G E O L O G I J A št.: 67/1, 2024 www.geologija-revija.si 7 Žvab Rožič, P. Hydrogeochemical and Isotopic Characterisation of the Učja Aquifer, NW Slovenia 25 Gale, L. & Rožič, B. Signs of crustal extension in Lower Jurassic carbonates from central Slovenia 41 Gosar, M., Bavec, Š., Miler, M. & Gaberšek, M. Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov, ki odvodnjavajo odlagališča rudarskih odpadkov 63 Dernov, V. Palaeoecological significance of the trace fossil Circulichnis Vyalov, 1971 from the Carboniferous of the Donets Basin, Ukraine 71 Skaberne, D., Čar, J., Pristavec, M., Rožič, B. &. Gale, L. Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia 105 Kanduč, T. & Markič, M. Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals 129 Placer, L., Popit, T. & Rižnar, I. Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain 157 Mencin Gale, E., Kralj, P., Trajanova, M., Gale, L. & Skaberne, D. Petrology dataset of Pliocene-Pleistocene sediments in northeastern Slovenias ISSN 0016-7789 2024 | št.: 67/1 20 24 | št .: 67 /1 ISSN Tiskana izdaja / Print edition: 0016-7789 Spletna izdaja / Online edition: 1854-620X GEOLOGIJA 67/1 – 2024 GEOLOGIJA 2024 67/1 1-185 Ljubljana GEOLOGIJA ISSN 0016-7789 Izdajatelj: Geološki zavod Slovenije, zanj direktor dr. Miloš Bavec Publisher: Geological Survey of Slovenia, represented by Director dr. Miloš Bavec Financirata Javna agencija za raziskovalno in inovacijsko dejavnost Republike Slovenije in Geološki zavod Slovenije Financed by the Slovenian Research and Innovation Agency and the Geological Survey of Slovenia UREDNIŠTVO / EDITORIAL TEAM Glavna in odgovorna urednica / Editor-in-Chief: dr. Mateja Gosar, Geological Survey of Slovenia, Ljubljana, Slovenia Tehnična urednica / Technical Editor: Bernarda Bole, Geological Survey of Slovenia, Ljubljana, Slovenia ČLANI TEHNIČNEGA UREDNIŠTVA / TECHNICAL EDITORIAL TEAM Vida Pavlica, Geological Survey of Slovenia, Ljubljana, Slovenia Maks Šinigoj, Geological Survey of Slovenia, Ljubljana, Slovenia Irena Trebušak, Geological Survey of Slovenia, Ljubljana, Slovenia Marko Zakrajšek, Marko Zakrajšek, e-Tutor s.p., Kranj, Slovenia UREDNIŠKI ODBOR / EDITORIAL BOARD Dunja Aljinović, Faculty of Mining Geology and Petroleum Engineering, Zagreb, Croatia Kristine Asch, Federal Institute for Geosciences and Natural Resources (BGR), Hannover, Germany Maria João Batista, National Laboratory of Energy and Geology, Lisbon, Portugal Giovanni Battista Carulli, University of Trieste, Department of Mathematics and Earth Sciences, Trieste, Italy Miloš Bavec, Geological Survey of Slovenia, Ljubljana, Slovenia Mihael Brenčič, University of Ljubljana, Faculty of Natural Sciences and Engineering and Geological Survey of Slovenia, Ljubljana, Slovenia Stefano Covelli, University of Trieste, Department of Mathematics, Informatics and Geosciences, Trieste, Italy Katica Drobne, Research Centre of the Slovenian Academy of Sciences an Arts, Ivan Rakovec Institute of Palaeontology, Ljubljana, Slovenia Jadran Faganeli, University of Ljubljana, Biotechnical Faculty Ljubljana, Slovenia Lászlo Fódor, Eötvös Loránd University, Budapest, Hungary Luka Gale, University of Ljubljana, Faculty of Natural Sciences and Engineering and Geological Survey of Slovenia, Ljubljana, Slovenia Špela Goričan, Research Centre of the Slovenian Academy of Sciences an Arts, Ivan Rakovec Institute of Palaeontology, Ljubljana, Slovenia Andrej Gosar, Slovenian Environment Agency and University of Ljubljana, Faculty of Natural Sciences and Engineering, Ljubljana, Slovenia János Haas, Etvos Lorand University, Budapest, Hungary Mitja Janža, Geological Survey of Slovenia, Ljubljana, Slovenia Mateja Jemec Auflič, Geological Survey of Slovenia, Ljubljana, Slovenia Bogdan Jurkovšek, Geological Survey of Slovenia, Ljubljana, Slovenia Roman Koch, GeoZentrum Nordbayern, Institute of Palaeontology, Erlangen, Germany Marko Komac, Marko Komac s.p., Ljubljana, Slovenia Harald Lobitzer, GeoSphere Austria, Vienna, Austria Tamara Marković, Croatian Geological Survey, Zagreb, Croatia Miloš Miler, Geological Survey of Slovenia, Ljubljana, Slovenia Rinaldo Nicolich, University of Trieste, Trieste, Italy Simon Pirc, University of Ljubljana, Faculty of Natural Sciences and Engineering, Ljubljana, Slovenia Frank Preusser, University of Freiburg, Institute of Earth and Environmental Science, Freiburg, Germany Roberto Rettori, University of Perugia, Department of Physics and Geology, Perugia, Italy Mihael Ribičič, University of Ljubljana, Faculty of Natural Sciences and Engineering, Ljubljana, Slovenia Nina Rman, Geological Survey of Slovenia, Ljubljana, Slovenia Boštjan Rožič, University of Ljubljana, Faculty of Natural Sciences and Engineering, Ljubljana, Slovenia Milan Sudar, University of Belgrade, Faculty of Mining and Geology, Beograd, Serbia Kristina Šarić, University of Belgrade, Faculty of Mining and Geology, Beograd, Serbia Sašo Šturm, Institut »Jožef Stefan«, Ljubljana, Slovenia Gevorg Tepanosyan, Center for Ecological-Noosphere Studies NAS RA, Yerevan, Armenia Timotej Verbovšek, University of Ljubljana, Faculty of Natural Sciences and Engineering, Ljubljana, Slovenia Miran Veselič, Faculty of Civil and Geodetic Engineering, University of Ljubljana, Ljubljana, Slovenia Michael Wagreich, University of Vienna, Department of Geology, Vienna, Austria Nina Zupančič, University of Ljubljana, Faculty of Natural Sciences and Engineering, Ljubljana, Slovenia Naslov uredništva / Editorial Office: GEOLOGIJA Geološki zavod Slovenije / Geological Survey of Slovenia Dimičeva ulica 14, SI-1000 Ljubljana, Slovenija Tel.: +386 (01) 2809-700, Fax: +386 (01) 2809-753, e-mail: urednik@geologija-revija.si URL: https://www.geologija-revija.si/ GEOLOGIJA izhaja dvakrat letno. / GEOLOGIJA is published two times a year. 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Baze, v katerih je Geologija indeksirana / Indexation bases of Geologija: Scopus, Directory of Open Access Journals, GeoRef, Zoological Record, Geoscience e- Journals, EBSCOhost Cena / Price Posamezni izvod / Single Issue Letna naročnina / Annual Subscription Posameznik / Individual: 15 € Posameznik / Individual: 25 € Institucija / Institutional: 25 € Institucija / Institutional: 40 € Tisk / Printed by: TISKARNA JANUŠ d.o.o. Slika na naslovni strani: Mikrofaciesi klastov pliocensko-pleistocenskih sedimentov Dravsko-Ptujskega bazena (foto: Eva Mencin Gale). Cover page: Microfacies of the clasts in the Pliocene-Pleistocene sediments in the Drava-Ptuj Basin (photo: Eva Mencin Gale). GEOLOGIJA 67/1, 1-185, Ljubljana 2024 VSEBINA – CONTENTS Članki - Articles Žvab Rožič, P. Hydrogeochemical and Isotopic Characterisation of the Učja Aquifer, NW Slovenia ...................................................7 Hidrogeokemična in izotopska karakterizacija vodonosnika Učje, SZ Slovenija Gale, L. & Rožič, B. Signs of crustal extension in Lower Jurassic carbonates from central Slovenia .................................................... 25 Znaki ekstenzije skorje v spodnjejurskih karbonatih osrednje Slovenije Gosar, M., Bavec, Š., Miler, M. & Gaberšek, M. Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov, ki odvodnjavajo odlagališča rudarskih odpadkov ........................................................................................................41 Contents of potentially toxic elements in sediments and waters of the Meža river and its tributaries draining mine waste deposits Dernov, V. Palaeoecological significance of the trace fossil Circulichnis Vyalov, 1971 from the Carboniferous of the Donets Basin, Ukraine ................................................................................................................................................... 63 Paleoekološki pomen fosilne sledi Circulichnis Vyalov, 1971 iz karbona Doneškega bazena v Ukrajini Skaberne, D., Čar, J., Pristavec, M., Rožič, B. &. Gale, L. Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia ....................................... 71 Srednjetriasna globljemorska vulkansko-sedimentna zaporedja v zahodni Sloveniji Kanduč, T. & Markič, M. Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals ........................................................................................................................................................................ 105 Izotopska sestava ogljika (δ13C) in dušika (δ15N) petrološko različnih terciarnih lignitov in premogov Placer, L., Popit, T. & Rižnar, I. Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain .............................................................................................................................................................. 129 Tektonika in gravitacijski pojavi, drugi del: Trnovsko-banjško-šentviška degradirana uravnava Podatkovni članki - Data Articles Mencin Gale, E., Kralj, P., Trajanova, M., Gale, L. & Skaberne, D. Petrology dataset of Pliocene-Pleistocene sediments in northeastern Slovenia.................................................... 157 Podatki o petrologiji pliocensko-pleistocenskih sedimentov severovzhodne Slovenije Poročila in ostalo - Reports and More Rajver, D.: 7. Svetovni geotermalni kongres WGC 2023, Peking (Kitajska) 15.–17. september 2023 ......................161 Novak, M.: Poročilo slovenskega nacionalnega odbora za geoznanosti in geoparke (IGGP) za leto 2023 .............. 169 Švara, A.: Poročilo o aktivnostih Slovenskega geološkega društva v letu 2023 ........................................................ 171 Nove publikacije - New Publications Veselič, M.: Decrouez, D., Finger, W., Haldimann, P., Hofstetter, J.-C., Kündig, R., Meyer, C., Mumenthaler, T., Sieber, N., Spescha, R., Testaz, G. et al. (eds.) 2018: Stein und Wein: Entdeckungreisen durch schweizerischen Rebbaugebiete, AS Verlag & Grafik, Zürich: 612 p. .................................................................... 178 © Author(s) 2024. CC Atribution 4.0 License Hydrogeochemical and Isotopic Characterisation of the Učja Aquifer, NW Slovenia Hidrogeokemična in izotopska karakterizacija vodonosnika Učje, SZ Slovenija Petra ŽVAB ROŽIČ University of Ljubljana, Faculty of Natural Sciences and Engineering, Department of Geology, Aškerčeva 12, SI–1000 Ljubljana, Slovenia; e-mail: petra.zvabrozic@ntf.uni-lj.si Prejeto / Received 23. 10. 2023; Sprejeto / Accepted 2. 2. 2024; Objavljeno na spletu / Published online 7. 2. 2024 Key words: groundwater, hydrogeochemistry, isotopes, cross-border aquifer, Učja Valley Ključne besede: podzemna voda, hidrogeokemija, izotopi, čezmejni vodonosnik, dolina Učje Abstract The groundwater characteristics of the Učja aquifer were investigated using geochemical and isotopic data. The water discharge and physico-chemical properties of the groundwater and the Učja River ref lect the climate that is characteristic of the area. The mixed snow/rainfall regime is characteristic for the Učja Valley, with the highest discharges appearing during the spring snowmelt and autumn precipitation, and the lowest discharges in the winter and especially summer months. The temperature of the groundwater and the Učja River is lower in winter and higher in summer. The specific electrical conductivity values indicate a very permeable carbonate aquifer. Higher conductivity values were observed in spring and autumn at all sampling sites, which is related to snowy and rainy periods. The groundwater from the Učja aquifer indicates a uniform type of water (Ca-Mg-HCO3), with Ca2+, Mg2+ and HCO3 – the most abundant ions. Differences in Ca2+ and Mg2+ concentrations and in the Mg2+/Ca2+ molar ratio between sampling sites were observed. Those springs with lower Mg2+ and lower Mg2+/Ca2+ molar ratios indicate limestone recharge areas, and those springs with higher Mg2+ and molar ratios indicate interaction with the dolomite hinterland. The pH values confirm alkaline waters characteristic of carbonate aquifers. The hydrogen (δ2H) and oxygen (δ18O) isotope values suggest the main source of water is from precipitation from a complex mixing of maritime and continental air masses. An altitude isotopic effect is observed with minor δ18O and δ2H depletion at higher altitude sampling sites compared to those springs at lower altitudes. The altitude isotopic effect is most prominent in spring. The δ13CDIC values indicate the dissolution of carbonates and the degradation of organic matter. Izvleček Značilnosti podzemne vode vodonosnika doline Učje so bile raziskane z uporabo geokemijskih in izotopskih podatkov. Pretoki in f izikalno-kemijski parametri reke Učje in podzemne vode na izvirih odražajo podnebne značilnosti območja. Za dolino Učje je značilen mešani snežno-dežni režim z največjimi pretoki v času spomladanskega taljenja snega in jesenskih padavin ter najnižjimi pretoki pozimi in predvsem poleti. Temperatura podzemne vode in reke Učje je pozimi nižja in poleti višja. Rezultati specifične elektroprevodnosti kažejo na zelo prepusten karbonatni vodonosnik. Na vseh vzorčnih mestih so bile izmerjene višje vrednosti spomladi in jeseni, kar povezujem s snežnimi in deževnimi obdobji. Podzemna voda vodonosnika doline Učje je enotnega tipa (Ca-Mg-HCO3) z najvišjimi koncentracijami Ca2+, Mg2+ in HCO3 – ionov. Med vzorčnimi mesti so bile ugotovljene razlike v koncentracijah Ca2+ in Mg2+ ter molskim razmerjem Mg2+/Ca2+. Izviri z nižjimi vrednostmi Mg2+ in nižjim molskim razmerjem izkazujejo apnenčevo napajalno območje, izviri z višjimi vrednostmi Mg2+ in višjim molskim razmerjem pa interakcijo z dolomitom. Vrednosti pH potrjujejo alkalnost voda, značilnih za karbonatne vodonosnike. Vrednosti izotopov vodika (δ2H) in kisika (δ18O) kažejo, da so glavni vir vode v vodonosniku padavine, ki nastanejo ob kompleksnem mešanju morskih in celinskih zračnih mas. Višinski izotopski efekt je opazen v nižjih vrednostih δ18O in δ2H na vzorčnih mestih višjih nadmorskih višin v primerjavi z izviri na nižjih nadmorskih višinah. Višinski izotopski učinek je najizrazitejši spomladi. Vrednosti δ13CDIC odražajo raztapljanje karbonatov in razgradnjo organske snovi. GEOLOGIJA 67/1, 7-24, Ljubljana 2024 https://doi.org/10.5474/geologija.2024.001 8 Petra ŽVAB ROŽIČ Introduction Geochemical studies of surface and groundwa- ter play an important part in understanding the mechanisms determining water chemistry (Gibbs, 1970). Karst and fractured aquifers pose a spe- cific challenge due to their heterogeneity and the special geochemical processes at work in aquifers (Ford & Williams, 2007; Moral et al., 2008; New- man, 2005; White, 1988). Understanding the wa- ter f low in aquifers and the connections between the atmosphere and deeper aquifers is essential (Allshorn et al., 2007; Keim at al., 2012; Maurice et al., 2021). The characteristics of spring water are the result of the mixing of groundwaters, in- teraction with the host rocks in the aquifer, and fresh surface water from precipitation with specif- ic climate-related characteristics (Khadka & Rijal, 2020; White, 2010). Karst springs often respond very quickly and intensively to rainy events, while their response to snowmelt varies in space and time (Weber et al., 2016) and also depends on oth- er climatic factors. Both sources of water contrib- ute considerably to aquifer recharge and are useful in understanding the impact of the composition of precipitation on groundwater (spring water). Hydrogeochemical and isotopic data provide us with information about groundwater sources and residence times, aquifer properties, water-rock in- teraction along the f low path, and the mixing of different types of water (Cartwright et al., 2012). The temporal and spatial variability of major ions in karstic waters is important in an understanding of chemical and physical processes inf luenced by geological conditions, climate, and anthropogenic activities (Gibbs, 1970; Meybeck, 1987). The iso- topic compositions of hydrogen and oxygen of wa- ter and carbon in the dissolved inorganic carbon, in combination with meteorological, hydrological, hydrogeological, and physicochemical data all help us to characterise and trace waters through the hydrological cycle (Dansgaard, 1964; Kendall & Doctor, 2003; Kanduč et al., 2012; Torkar et al., 2016; Calligaris et al., 2018; Shamsi et al., 2019; Serianz et al., 2021 and others). Stable isotopes of hydrogen (δ2H) and oxygen (δ18O) are used to determine the source of the water and residence time, the f low of water through the water body, or to quantify exchanges of water, solutes, and partic- ulates between hydrological compartments to in- dicate the potential water inputs to the system and characterize the inf luence of different processes during infiltration, and to determine the mixing of waters of different origins within the system (Ag- garwal at al., 2005; Clark & Fritz, 1997; Glynn & Plummer, 2005; Rodgers et al., 2005). Carbon iso- topes help us to assess the origin of dissolved inor- ganic carbon (DIC), the main component in waters draining carbonate systems. The isotope compo- sition of dissolved inorganic carbon (δ13CDIC) is used to understand the biogeochemical reactions controlling alkalinity and to trace the origin of the bicarbonate ion, which is the dominant anion in the shallow groundwater (Bullen & Kendall, 1998). Almost half of the Slovenian territory is char- acterized by karst (Gams, 1974, 2004; Gostinčar & Stepišnik, 2023). These systems are often vast reservoirs of high quality water and thus impor- tant sources of drinking water (Ravbar & Kovačič, 2006). Studies of karst aquifers are complex but pose important research challenges within the frame of determining and protecting potential sources of drinking water. In the past, various hydrogeological research has been carried out in the area of the Kanin (Komac, 2001; Turk et al., 2014; Zini et al., 2014; Russo, 2015) and Kobariški stol aquifers (Brenčič et al., 2001), while the Učja Valley has not yet been studied in detail. The Učja aquifer represents a cross-border karstic aquifer, which may contain large amounts of quality groundwater (Brenčič et al., 2001; Rejc, 2014), and could in the future rep- resent an important source of drinking water or a commercial source as well, as it could be used as a significant water resource for cross-boundary supply. As a result, a comprehensive survey of the potential of the Učja aquifer was carried out. Various geological studies have been made of the wider investigated area in the past, which provide basic data for detailed lithological and structural maps of the territory. The first geolog- ical studies were made already in the 1970s and 1980s to produce basic geological maps (Kuščer, 1974; Buser, 1986, 1987). Later, due to the very complex tectonic structure of the area, numerous regional and local studies of the Učja Valley and its surroundings were elaborated (Čar & Pišljar, 1991, 1993; Vrabec, 2012). The lithology of the Mt. Kobariški Stol area, which represents the southern slopes of the Učja Valley, was described by Šmuc (2012) and is currently investigated in greater de- tail (Rožič et al., 2022; Vantur, 2023). From the hydrogeological point of view, the springs of the wider area were listed and described (Brenčič et al., 2001; Janež, 2002), whereas within the frame- work of national monitoring only hydrological measurements of surface water on the Učja River are carried out. A basic hydrogeological analysis of the Učja was also described (Rejc, 2014). 9Hydrogeochemical and Isotopic Characterisation of the Učja Aquifer, NW Slovenia The aim of this paper is to characterise the groundwater of the Učja aquifer. Physico-chemical parameters (T, EC, pH), hydrogeochemical com- position (cations and anions) and isotopic tracers (δ2H, δ18O, δ13CDIC, 3H) were used to characterize the (1) water–rock interaction in the aquifer, (2) the origin of the groundwater using isotopic trac- ers, and (3) the origin of carbon in the dissolved inorganic carbon to evaluate the biogeochemical processes at work in the groundwater. The present- ed results, in combination with other segments of the aquifer (geological conditions, climate land use characteristics, geochemical modeling etc.), will provide a useful basis for the further planning of the use and protection of the Učja water resource. The importance of the results extends beyond Slovenia’s borders, in terms of cross-border shar- ing of knowledge, coordination, and the potential cross-border planning and management of com- mon water resources. Study area Sampling location The Učja Valley is located in NW Slovenia be- tween the towns of Bovec and Kobarid. The val- ley extends in the W-E direction, and is bounded on the south and north by mountain ridges: the Kobariški stol ridge (with the highest peak Stol or Veliki Muzec, 1673 m) in the south and the ridge with the Skutnik peak (1721 m), which is part of the Kanin ridge in the north. The western border is defined by the state border with the Republic of Italy, and to the east by the Soča River valley near the village of Žaga (Fig. 1). The W-E orientation of the Učja Valley is unique from a tectonic point of view, as it almost perpendicularly cuts the en- tire fault zone of the Idrija fault (Fig. 2), one of the most prominent fault zones in western Slovenia (Čar & Pišljar, 1991; Vrabec, 2012). The area has a typical mountain morphology with steep slopes in the north and south, with the gorge of Učja River between them (Fig. 1). The northern and southern slopes descend towards the valley at an average gradient of 25–45°, with vertical slopes of some mountains, ridges, and gorges. The northern slopes in some parts above the river rise vertically up to 300 m, but then de- crease slightly (on average 40°). Due to the prom- inent ruggedness and especially steep slopes of the terrain, some parts are completely impassable and work in such areas is very difficult. Towards the west of the researched area, where the Učja River f lows into the Soča River, the slope of the Fig. 1. Geographic location of the Učja Valley with marked sampled springs in the study area (source map Geopedia; 13.36402° W, 13.52413° E, 46.33777° N, 46.26382° S). The hydrographic area of the Slovenian part of the Učja Valley is presented (ARSO, 2019b). 10 Petra ŽVAB ROŽIČ terrain decreases considerably (15–20°) and final- ly levels out on the alluvial plain of the Soča River. The Učja river originates under the western slopes of the Kanin ridge in Italy and f lows into Slovenia through a narrow gorge. After 18 km, the Učja Riv- er f lows into the Soča River as the right and second largest tributary near the village of Žaga. The Učja gorge is registered in the Nature Conservation At- las (ZRSVN, 2023) as Natural Value (ID 775). The Hydrogeological characteristics of the Učja Valley are directly dependent on the geological characteristics of the wider area (Fig. 2). Most of the main springs are located at the foot of the mountain slopes near the transition to the alluvial plain of the Soča Valley and appear along the Idri- ja fault (Fig. 1 and 2). A few springs were defined along the Učja riverbed (Čar & Pišljar, 1991), and individual springs higher up on the slopes, most likely linked to lithological changes or strong tec- tonic structures. Part of the groundwater (springs) is captured for drinking water in the public water supply network, while some springs are used for private drinking water supply. These springs also have water permits. Water protection zones are not defined for any of the springs (ARSO, 2019a). Water for geochemical and isotopic analyses was sampled at 13 locations in the Učja Valley (Fig. 1 and 2). The spring water (groundwater) was sampled at twelve sampling sites (UC1-UC8, UC10-UC13) as well as one additional water sam- ple from the Učja River (surface water, UC9). In this work, the results of 11 sampling sites are pre- sented (Table 1), while two sites (UC10, UC13) are not considered in the evaluation due to a lack of data. Seven sampling sites were positioned at the foot of the mountain slopes (UC3-UC8, UC12; on f igures marked with circles), near the transition to the alluvial plain of the Soča Valley. These springs are located west of the Idrija fault zone and one of them (UC12) in the fault zone. These sampling sites are located at altitudes of 389–480 m asl. Three sampling sites (UC1, UC2, UC11; on figures marked with squares) are located on the slopes of the Kobariški stol ridge near the former border crossing station with the Republic of Italy. These sampling sites are located at altitudes of 758–700 m asl. Sampling site UC9 (Učja stream water; on f igures marked with a triangle) was located ap- proximately 50 m upstream of the road bridge at the Žaga hydrological station. Table 1. Details of sampling locations in the Učja Valley (*not considered in this research), sampling periods of in-situ field measurements (physico-chemical parameters) and periods of laboratory analyses (geochemical and isotopic analyses – δ18O, δ2H, total alkalinity, δ13CDIC 3H). Label LAT [°] LONG [°] Altitude [m] Water type Sampling period (in-situ field measurements) Sampling period (laboratory measurements) Geochemical analyses δ18O, δ2H, total alkalinity, δ13CDIC Tritium (3H) UC1 46,29615 13,43663 758 Spring December 2017, January 2018, March 2018, April 2018, 2x June 2018, July 2018, August 2018, October 2018, November 2018, December 2018, March 2019 December 2017, April 2018 December 2017, April 2018, July 2018, October 2018 December 2017 UC2 46,29750 13,43778 707 Spring December 2017, January 2018, March 2018, April 2018, 2x June 2018, November 2018, December 2018, March 2019 Same as UC1 December 2017, April 2018 Same as UC1 UC3 46,30250 13,47594 437 Spring Same as UC1 Same as UC1 Same as UC1 Same as UC1 UC4 46,30222 13,47611 449 Spring Same as UC1 Same as UC1 Same as UC1 Same as UC1 UC5 46,30398 13,47432 480 Spring Same as UC1 Same as UC1 Same as UC1 Same as UC1 UC6 46,30431 13,47498 451 Spring Same as UC1 Same as UC1 Same as UC1 Same as UC1 UC7 46,30347 13,47806 389 Spring Same as UC1 Same as UC1 Same as UC1 Same as UC1 UC8 46,30377 13,47710 411 Spring Same as UC1 Same as UC1 Same as UC1 Same as UC1 UC9 46,30972 13,47805 342 River Same as UC1 Same as UC1 Same as UC1 Same as UC1 UC10* 46,30996 13,47887 367 Spring December 2017, January 2018, March 2018, April 2018, June 2018 – – – UC11 46,29795 13,43901 700 Spring January 2018, March 2018, April 2018, 2x June 2018, November 2018, December 2018, March 2019 April 2018 December 2017, April 2018 – UC12 46,30787 13,47196 447 Spring December 2017, January 2018, March 2018, April 2018, 2x June 2018, October 2018, November 2018, December 2018, March 2019 April 2018 April 2018, October 2018 – UC13* 46,29218 13,44839 985 Spring June 2018 – – – 11Hydrogeochemical and Isotopic Characterisation of the Učja Aquifer, NW Slovenia Geological setting The area of the Učja Valley structurally belongs to the Southern Alps and is characterized by Mio- cene south-directed thrusting (Fig. 2). The major part of the Učja Valley consists of a succession of the Tolmin Nappe, i.e. the lowest of the South- alpine nappes, whereas the highest peaks of the Kanin ridge (northern slopes of Učja Valley) are composed of the structurally higher Krn (Julian) Nappe. Thrust units are further displaced by neo- tectonic strike-slip faults (Placer, 1999, 2008). The most prominent is the NW-SE oriented Idrija fault zone that generally runs east of the Učja Valley, i.e. along the Soča Valley between the town of Tolmin and the village of Žaga, through the Kanin ridge and enters the Rezija (Resia) Valley near Mt. Sku- tnik. A few minor faults parallel to the Idrija fault zone run across the Učja Valley. On the southern slopes of the Učja Valley important E-W trending vertical faults divide two slightly diverse strati- graphic successions (Buser, 1987). The entire area is dominated by a thick succes- sion of Upper Triassic carbonates (Fig. 2). In the Kobariški stol ridge the succession starts with the Norian Hauptdolomit (Main Dolomite) formation passing upward into the Norian-Rhaetian Dachstein Limestone formation, which is covered further by Lower Jurassic platform limestone (Buser, 1986, 1987). Above the stratigraphic gap, the Middle Ju- rassic limestone breccia and thin-bedded hemipe- lagic limestone follows and is in turn replaced by Upper Jurassic ammonitico rosso-type limestone of the Prehodavci formation, and finally the end Ju- rassic-earliest Cretaceous pelagic Biancone Lime- stone formation. These three units are condensed, only reaching several tens-of-meters in thickness (Šmuc, 2012; Rožič et al., 2022; Vantur, 2023). Above, an end-Cretaceous Upper f lyschoid forma- tion is deposited, composed of alternating shale/ marl and graded sandstone. At the base of the for- mation, laterally discontinuous limestone breccia beds are deposited. Similar beds occur also as in- terbeds within f lysch-type deposits (Vantur, 2023). North of the E-W trending fault, i.e. in the cen- tral part of the Učja Valley, only the Norian-Rhae- tian is developed as the Hauptdolomit formation. With the erosional contact, it is overlain with Up- per Cretaceous deep-marine Volče Limestone for- mation (resedimented and pelagic limestone) and upwards by an Upper f lyschoid formation highly similar to the one described above. The Krn Nappe, which is thrust over the soft bed of the Upper f ly- schoid formation, is composed almost exclusive- ly of the Norian-Rhaetian Dachstein Limestone formation with only local occurrences of dolomite (Buser, 1986, 1987). Fig. 2. Geological map of the Učja Valley with sampled springs marked (modified after Buser, 1987; source map in background from ARSO, 2019a; 13.36482° W, 13.50750° E, 46.33294° N, 46.27038° S). The hydrographic area of the Slovenian part of the Učja Valley is presented (ARSO, 2019b). 12 Petra ŽVAB ROŽIČ Materials and methods In-situ measurements and water sampling were carried out from December 2017 to March 2019. Information about sampling and laboratory anal- yses for individual sampling sites is presented in Table 1. The missing measurements in the ta- ble are the result of the absence of spring water (springs were dry) at the time of sampling. The measurements of physico-chemical pa- rameters (temperature, pH, specific electrical con- ductivity) were measured on a monthly basis or at least every two months (Table 1) using a WTW Multi 3430 Multiparameter probe (WTW GmbH, Weilheim, Germany). Additionally, the discharge of springs was observed and, where possible, measured in the field using a bucket (Fig. 5). The Učja River discharge and the precipitation of the area is measured in the frame of the Slovenian na- tional monitoring system. Data from the gauging hydrological station Žaga – Učja (46.30978º N, 13.47774º E, 342 m a.s.l.) was used to analyse the discharge of the Učja River (ARSO, 2019c). Discharge measurements at the gauging station are monitored every 10 minutes. Data from the Bovec meteorological gauging station (46.33171º N, 13.55382º E, 441 m a.s.l.) was used to analyse the precipitation f luctuations in the area (ARSO, 2023). The amount of precipitation at the gauging station is measured every half hour. Two rounds of hydrogeochemical analysis and four rounds of isotopic analysis were performed on a seasonal basis (Table 1). Water samples for hy- drogeochemical analysis were collected in 50 mL in high-density polyethylene HDPE bottles. For cations, the water was further filtered through a 0.45 µm nylon filter and pre-treated with HNO3 – on site. Analyses were performed in the ActLabs ac- credited laboratory (Activation Laboratories Ltd., Ancaster, ON, Canada). Cations (major, minor, and trace) were analysed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), with some of the major cations (e.g. Ca2+, Mg2+) also analysed using Overrange Inductively Coupled Plasma-Op- tical Emission Spectrometry (ICP-OES) due to some excessively high concentrations for ICP-MS, and major anions (Br-, Cl-, F-, NO2 2-, NO3 -, PO4 3-, SO4 2-) were determined using Ion Chromatography (IC). Internal laboratory reference materials and independent quality control with duplicates (one for each measurement campaign) were measured. Detection limits for each element or compound for individual methods are reported on the ActLabs homepage (ActLabs, 2023). Water samples for oxygen (δ18O) and hydrogen isotope (δ2H) analysis (Table 1) were collected in 50 mL HDPE bottles. The isotopic composition of oxygen and hydrogen was determined at the Jožef Stefan Institute using the H2 – H2O (Coplen et al., 1991) and CO2 – H2O (Avak & Brand, 1995; Ep- stein & Mayeda, 1953) equilibration technique on a dual inlet isotope ratio mass spectrometer (Fin- nigan MAT DELTA plus) with a CO2 – H2O and H2 – H2O HDOeq 48 automatic equilibrator and a water bath at 18°C (Kanduč et al., 2018a, 2018b, 2018c, 2018d). CO2 (Messer 4.7) and H2 (IAEA) gasses were used as working standards for water equilibration. Two laboratory reference materials (LRM), such as W-3896 and W-3871, calibrated to the international VSMOW-SLAP scale, were used to normalize the data. LRM W-45 and commercial reference materials USGS 45, USGS 46, and USGS 47 were used for the independent quality control of measurements as also described in Žvab Rožič et al. (2021). The average repeatability of the sam- ples was 0.02 ‰ for δ18O and 0.3 ‰ for δ2H, with results expressed as a δ-value per mil (‰). For the analysis of total alkalinity (TA) and iso- tope composition of dissolved inorganic carbon (δ13CDIC) (Table 1), water was filtered through a 0.45 µm pore-sized membrane filter. Samples were stored in 30 mL HDPE bottles for TA and 12 in mL Labco glass vials with septum, without headspace, for δ13CDIC analyses. Before TA analyses in the labo- ratory, pH was measured using a pH meter (Mettler Toledo AG 8603, Schwerzenbach, Switzerland). To- tal alkalinity (TA) was measured within 24 hr after sampling using the Gran titration method (Giesk- es, 1974; Kanduč, 2006) to determine the results with an accuracy of ±1%. Approximately 8 g of the water sample was weighed into a plastic container and placed on a magnetic stirrer. A calibrated pH electrode (7.00 and 4.00 ± 0.02) was placed in the sample and the initial pH was recorded. Titration was performed using a CAT titrator (Ingenierbüro CAT, M. Zipperer GmbH Ballrechten-Dottingen, Germany). Reagencon HCl 0.05 N (0.05 M) was used for the titration (Kanduč et al., 2018a, 2018b, 2018c, 2018d). The method is described in detail by Zuliani et al. (2020). The isotope composition of dissolved inorganic carbon (δ13CDIC) was determined according to the Spötl procedure ( Spötl, 2005; Kanduč, 2006). Am- poules of saturated phosphoric acid (100-20 µL) were f lushed with pure helium, 6 ml of the water sample was added, and headspace CO2 was meas- ured. The δ13CDIC values were determined using a continuous f low Europa Scientific 20-20 isotope mass spectrometer with the ANCA - TG prepa- ration module (Sercon Limited, Crewe, UK). A standard solution of Na2CO3 (Carlo Erba reagents, 13Hydrogeochemical and Isotopic Characterisation of the Učja Aquifer, NW Slovenia Val de Ruil, France) and a Scientific Fischer sam- ple with known δ13CDIC values of -10.8 ‰ ± 0.2 ‰ and -4.8 ‰ ± 0.1 ‰ were used to calibrate the measurements. Messer reference gas with known δ13CCO2 -35.5 ‰ ± 0.2 ‰ was also used. The ref- erence material (Carlo Erba solution) was used to convert the analytical results to the Vienna Pee Dee Belemnite (VPDB) scale. The average sample repeatability was 0.2 ‰. Two replicates of each sample were measured. Results are expressed as a δ-value per mil (‰) (Kanduč et al., 2018a, 2018b, 2018c, 2018d). For tritium (3H) the water was sampled once in 1 L HDPE bottles. The tritium (3H) was measured in Hydrosys Labor Ltd. in Budapest using a liquid scintillation counting (LSC) TriCarb 3170 TR/SL (PerkinElmer, Waltham, MA, USA). Before analy- sis, the sample was treated and prepared using elec- trolytic enrichment. Analysis error was ±0.3 TU, with a detection limit of 3 TU. Results and discussion Climate conditions and discharge regime The wider Učja Valley is located in a transition area between Alpine and Sub-mediterranean cli- mate zones. Winters are long and snowy, with De- cember and January the coldest months (Fig. 3). Fig. 4. Precipitation (blue) measured at the Bovec meteorological gauging station (ARSO, 2023) and discharge (dark grey) of the Učja River at the Žaga – Učja hydrological gauging station (ARSO, 2019c) for 2018. Fig. 3. Air temperature measured at the Bovec meteorological gauging station (ARSO, 2023). 14 Petra ŽVAB ROŽIČ Summers are moderately warm (around 20 ºC) with rare air temperatures above 30 ºC (Fig. 3). Higher amounts of precipitation fall in autumn and spring, and lower amounts in winter and summer (local showers) (Fig. 4). Precipitation in the region (measured at Bovec meteorologi- cal gauging station; ARSO, 2023) and at the Učja River discharge (measured at the Žaga – Učja hydrological gauging station; ARSO, 2019c) is plotted in Fig. 4. The most pronounced increase of Učja River discharge in spring (March-April) and autumn (November) is in accordance with the mixed snow/rainfall regime. Lower discharg- es are recorded in winter and especially during summer, and the highest discharges during the spring snowmelt and with autumn precipitation. A quick and intense response in the discharge of the river is also observed twice in winter. Dur- ing the summer, the response of river discharge to precipitation is not so intense, which may be the result of short and local summer showers (the Bovec gauging station is located some 10s of km northwest in the Soča Valley) and more intense evapotranspiration. Similar trends are also seen in the measured springs, with two periods of higher water discharge in the spring and autumn, and low or even no discharge in the summer (Fig. 5). Physico-Chemical Parameters of Učja aquifer Measured physico-chemical parameters are presented in Figures 6 and 7. The entire range of results are presented in common database in Pangaea repository (Žvab Rožič et al., 2024). The groundwater temperature of the springs and water from Učja River (Fig. 6) generally follow the f luc- tuations in air temperature (Fig. 3), and therefore ref lect the significant seasonal temperature condi- tions of the area. The highest water temperatures were measured in summer (max 18.7 ºC at UC6 in July 2018) and the lowest in winter (min 3.6 ºC at UC9 in December 2017 and 2018). More noticea- ble changes are recorded at the springs where the watershead area of the springs is smaller and sig- nificantly lower discharges were observed in the summer months. The quick response of groundwa- ter temperature to f luctuations in air temperature is also the result of water heating in the shallow or surface pipelines and reservoirs from which the water was sampled. The springs at higher altitudes (UC1, UC2, UC11; Fig. 1, Table 1) show less mark- able temperature f luctuations. This may be the re- sult of higher elevations and the shadier locations of spring areas in the valley and probably deep- er local recharge areas. The temperature trend of these springs is also less than entirely clear, be- cause the temperature was not measured at some sampling sites (UC2, UC11) due to a lack of water in the summer months. Fig. 5. Discharge of springs where taking of measurements was possible. Missing measurements are the result of the absence of spring water (springs were dry) at the time of sampling. 15Hydrogeochemical and Isotopic Characterisation of the Učja Aquifer, NW Slovenia The specific electrical conductivity (EC) of sampling water ranges from 186 to 438 μS/cm (average 266 μS/cm) (Fig. 7). The EC values in- dicate a highly permeable carbonate aquifer with a low resistence time as also described in Torkar & Brenčič (2015). The highest EC was observed at sampling site UC12 (max 438 μS/cm) and the low- est at sampling site UC2 (min 186 μS/cm). Low- er EC values were generally measured in spring waters at higher altitudes (UC1, UC2, UC11 – marked with squares; Fig.1, Table 1) and in the water from the Učja River (UC9 – marked with Fig. 6. Measured water temperatures (ºC) at sampling sites in the Učja Valley. Fig. 7. Field measurements of specific electrical conductivity (μS/cm) at sampling sites in the Učja Valley. 16 Petra ŽVAB ROŽIČ a triangle). The EC inversely related to elevation was also described for fractured dolomite aquifers in central Slovenia (Verbovšek & Kanduč, 2016). Slight f luctuations in EC values at all sampling sites is observed throughout the year. Rather low- er EC values were recorded in April-March and November-December, and related to snowmelt in spring and rainy periods in autumn (Fig. 4), and most likely also to lower evapotranspiration. A more prominent EC f luctuation is noticeable at the UC12 sampling site, with the lowest values in the spring and a marked decrease in November, which is associated with rainy periods (Fig. 4), and the highest in the summer before the spring dries up. The spring is also located within the tectonic zone of the Idirja fault (Čar & Pišljar, 1991, 1993; Vra- bec, 2012), where inf low and mixing with deeper waters with higher EC could occur. However, more precise explanations and processes in the aquifer remain to be developed and investigated. The pH of sampled water varied from 7.60 to 8.96, with an average value of 8.12, and ref lects the common characteristics of a carbonate aquifer, with no differences between sampling sites. The pH values are comparable with groundwater sam- ples from fractured dolomite aquifers in central Slovenia (Verbovšek & Kanduč, 2016). Hydrogeochemistry of the Učja aquifer The geochemical results for the Učja Valley aq- uifer are part of a common database in Pangaea re- pository (Žvab Rožič et al., 2024). The major com- position of groundwater from the Učja aquifer does not change between the two sampling campaigns (December 2017 and April 2018) and is dominat- ed by HCO3 –, Ca2+, and Mg2+ ions (Fig. 8), which is characteristic for carbonate types of waters. All samples belong to the Ca-Mg-HCO3 facies with low K+, Na+, Cl-, NO3 - and SO4 2+ content (Jäckli, 1970). Comparable results are also described for karstic April 2018 UC9 (Učja River) UC3 - UC8, UC12 (lower al�tude) UC1, UC2, UC11 (higher al�tude) December 2017 Legend UC9 (Učja River) UC3 - UC8 (lower al�tude) UC1, UC2 (higher al�tude) Ca2+ Mg 2+ N a + + K + CO 3 2- + H CO 3 - SO4 2- Cl - SO 4 2 - + Cl - Ca 2+ + M g 2+ Na + + K + CO3 2- + HCO3 - Fig. 8. Piper plot diagram of the Učja Valley water samples. 17Hydrogeochemical and Isotopic Characterisation of the Učja Aquifer, NW Slovenia and fractured aquifers in Central Slovenia (Ver- bovšek & Kanduč, 2016) and for the Triglavska Bistrica River in Northern Slovenia (Serianz et al., 2021). Total alkalinity ranged from 1.95 mM (UC1) to 3.40 mM (UC5), and concentrations of Ca2+ and Mg2+ from 27.0 mg/L (UC6) to 47.9 mg/L (UC12) and from 1.96 mg/L (UC1) to 20.9 mg/L (UC5), respectively. The Mg2+/Ca2+ molar ratio, which in- dicates the relative contribution of dolomite and calcite to the intensity of carbonate weathering in the groundwater, differs significantly between sampling sites: group I (UC1, UC2 and UC11) ex- hibits ratios ranging from 0.08 to 0.25 and group II (UC3-UC8) ratios ranging from 1.00 to 1.15. Sampling sites UC9 (Učja River) and UC12 show a Mg2+/Ca2+ molar ratio of 0.32. The same grouping is also visible on the Piper plot diagram (Fig. 8). The Mg2+/Ca2+ molar ratios are slightly higher than those found in descriptions of fractured dolomite aquifers in central Slovenia (Verbovšek & Kanduč, 2016). The results can be explained by the geologi- cal conditions of the area (Fig. 2). The springs from group II indicate that dolomite (the main rock in the catchment area) weathering is the source of the ma- jor solutes within the aquifer, while for group I the Ca2+ contribution from limestone layers (limestone breccia or thick platform limestone succession, as both are located south of the E-W trending fault) prevail (Fig. 2). Isotopic characteristics of the Učja aquifer The isotopic results for the Učja Valley aquifer are presented entirely in database in Pangaea reposito- ry (Žvab Rožič et al., 2024). The δ18O and δ2H val- ues for the groundwater from the Učja Valley vary from –8.7 ‰ to –7.4 ‰ (average –8.0 ‰) and from –54.9 ‰ to –45.1 ‰ (average –49.5 ‰), respec- tively. The surface water of the Učja River has δ18O values from –8.7 ‰ to –8.1 ‰ (average –8.4 ‰) and δ2H values from –55.3 ‰ to –50.4 ‰ (aver- age –52.6 ‰). δ18O and δ2H values vary seasonally at all sampling sites (Fig. 9). In general, the lowest values were measured during the spring sampling campaign (average -8.2 ‰ for δ18O and -51.8 ‰ for δ2H) and the highest during the winter sampling campaign (average -7.8 ‰ for δ18O and -48.0 ‰ for δ2H). Differences in the δ18O values are noticeable between sampling sites (Fig. 9). Higher δ18O values were recorded in springs UC1 and UC2 (from 0.6 to 0.7 ‰) and the Učja River (0.6 ‰), while in the re- maining springs (UC3-UC8, UC12) the amplitudes are lower (from 0.3 to 0.5 ‰). This may indicate rather longer residence times for the springs at low- er altitudes (UC3-UC8, UC12) due to the dolomite rocks in the watershed (Torkar et al., 2016). The results of δ18O and δ2H measurements of Učja groundwater and the Učja River are present- ed in Figure 10. For comparison, the results of se- lected previous studies from Northern and Central Slovenia (Kanduč et al., 2012; Zega et al., 2015; Verbovšek & Kanduč, 2016; Torkar et al., 2016; Serianz et al., 2021) are presented together with selected water lines: global meteoric water line (GMWL; δ2H = 8 × δ18O + 1 ‰; Craig, 1961), local meteoric water line for Kredarica (LMWLK; δ 2H = 8.42 (±0.19) × δ18O + 18.98 (±2.09); SLONIP, 2023), local meteoric water line for Zgornja Ra- dovna (LMWLZR; δ 2H = 7.98 (±0.13) × δ18O + 11.13 (±1.21); SLONIP, 2023), and local meteoric water line for Portorož (LMWLP; δ 2H = 8.09 (±0.2) × δ18O + 9.99 (±1.34); SLONIP, 2023). For Local meteoric lines the precipitated weighted reduced major axis regression (PWRMA LMWL) was used (Vreča et al., 2022; SLONIP, 2023). The isotopic composition of the groundwater from the Učja aq- uifer and the Učja River is similar to the isotopic composition of the Žveplenica sulfur karst spring (Zega et al., 2015), which is inf luenced by simi- lar climate conditions. If we compare the results with the springs from Northern Slovenia (Kanduč et al., 2012), from karst and fractured aquifers in Central Slovenia (Verbovšek & Kanduč, 2016), Ra- dovna Valley (Torkar et al., 2016), and Triglavska Bistrica (Serianz et al., 2021) (Fig. 10) the ground- water from the Učja Valley is enriched with heav- ier isotopes (i.e. 2H and 18O). This is attributed to the proximity of the Mediterranean climate, and the continental isotopic effect is ref lected in pre- cipitation (Kern et al., 2020; Vreča & Malenšek, 2016). The results from the Učja Valley show that all water samples are above the GMWL, LMWLZR and LMWLP, plotted between local meteoric water lines for Zgornja Radovna LMWLZR and especial- ly for Kredarica LMWLK. As already described in some previous studies (Vreča et al., 2006; Torkat et al., 2016), the results from the Učja Valley sug- gest a complex mixing of maritime and continental air masses. The δ18O and δ2H values in the groundwater of the Učja Valley reveal isotopic depletion (altitude isotopic effect) in the sampling locations (UC1, UC2, UC11) at higher altitudes (app. 720 m asl) compared to the locations (UC3-UC8, UC12) at lower altitudes (app. 440 m asl). In view of the difference between the UC1 (758 m asl) and UC7 (389 m asl) sampling sites, the average altitude ef- fect for the Učja Valley is 0.11 ‰ per 100 m for δ18O (the same as for the Radovna Valley; Torkar et al., 2016) and 0.45 ‰ per 100 m for δ2H. The altitude isotopic effect varies between seasons. 18 Petra ŽVAB ROŽIČ Fig. 9. Time series of isotopic compositions of δ18O and δ2H in groundwater of the Učja aquifer and the Učja River. Fig. 10. Plot of δ18O versus δ2H values for groundwater of the Učja aquifer (groundwater) and the Učja River, the results from selected previ- ous studies from Northern and Central Slovenia (Kanduč et al., 2012; Zega et al., 2015; Verbovšek & Kanduč, 2016; Torkar et al., 2016; Seri- anz et al., 2021), together with the global meteoric water line (GMWL) and the local meteoric water lines from Kredarica (LMWLK), Zgornja Radovna (LMWLZR) and Portorož (LMWLP) (Vreča et al., 2022; SLONIP, 2023). 19Hydrogeochemical and Isotopic Characterisation of the Učja Aquifer, NW Slovenia The least prominent altitude effect was found in winter (0.08 ‰ per 100 m for δ18O and 0.05 ‰ per 100 m for δ2H), and the highest in spring (0.2 ‰ per 100 m for δ18O and 1.11 ‰ per 100 m for δ2H). Seasonal differences in altitude effect were also described in precipitation across the Adriatic– Pannonian region (Kern et al., 2020). The δ13CDIC values for the groundwater of the Učja Valley vary from –12.6 ‰ to –8.3 ‰ (av- erage –10.7 ‰) and alkalinity from 2.0 mM and 3.4 mM (average 2.9 mM). The surface water of the Učja River has higher δ13CDIC values, from –7.4 ‰ to –6.8 ‰ (average –7.0 ‰), while the alkalinity is slightly lower than in groundwa- ter, from 2.2 mM and 2.6 mM (average 2.5 mM). Seasonal variations of δ13CDIC are generally ob- served with slightly higher values in the summer and noticeably lower values in the winter. Simi- lar trends were described for the Radovna Valley (Torkar et al., 2016). The geochemical processes inf luencing the δ13CDIC values in groundwater are presented in Figure 11 and described in Kanduč et al. (2012, 2016). Geochemical processes were cal- culated as follows: line1 (with a value of +1.2 ‰) – dissolution of carbonates according to the aver- age δ13CCaCO3 value – predicted value (Kanduč et al., 2012) resulting in 1 ‰ enrichment in 12C in DIC (Romanek et al., 1992), line 2 (with a value of –12.5 ‰) – nonequilibrium carbonate dissolu- tion by carbonic acid produced from soil zone CO2 (Kanduč et al., 2012; Verbovšek & Kanduč, 2016), and line 3 (with a value of –18.2 ‰) open sys- tem equilibration of DIC with soil CO2 originating from the degradation of organic matter with δ13Csoil –27.2 ‰ (Kanduč et al., 2012; Verbovšek & Kan- duč, 2016) (Fig. 8). There are a number of possible sources of carbon. All δ13CDIC values (Fig. 11) indi- cate that the groundwater from the Učja Valley is a resulting mixture of the dissolution of carbonates and the degradation of organic matter. The results are comparable with groundwater samples from springs of Northern Slovenia (Kanduč et al., 2012), individual karstic and fractured dolomite aquifers in Central Slovenia (Verbovšek & Kanduč, 2016), the Triassic aquifers of the Velenje Basin (Kanduč et al., 2016) and δ13CDIC measurements from the Radovna Valley (Torkar et al., 2016). Tritium (3H) concentrations in the groundwater from the Učja aquifer ranged from 3.0 to 4.5 TU (average 3.5 TU), which is close to the detection limit of the method. More measurements would be needed to understand the age of the water in more detail, and should be further investigated in the future. Fig. 11. Total alkalinity versus isotopic composition of dissolved inorganic carbon (δ13CDIC) of groundwater from the Učja aquifer and the Učja River, together with groundwater from northern Slovenia (Kanduč et al., 2012) and karstic and fractured aquifers from Central Slovenia (Verbovšek & Kanduč, 2016). See the explanation of dotted lines 1, 2, and 3 in Verbovšek & Kanduč (2016). 20 Petra ŽVAB ROŽIČ Conclusions The groundwater from the Učja aquifer, a cross-border karst aquifer in NW Slovenia, was characterised using geochemical and isotopic data. Analysis was carried out on water samples from 10 springs (groundwater) and on (surface) water from the Učja River. The measurements were performed over the period December 2017 to March 2019. The water discharge and physico-chemical pa- rameters of the Učja groundwater and the Učja River ref lect the climate that is characteristic of the area. The mixed snow/rainfall regime is char- acteristic for the Učja Valley. Lower discharges of the Učja River are recorded in winter and espe- cially during summer, with the highest discharges seen during the spring snowmelt (March-April) and in autumnal precipitation (November). Simi- lar trends are also seen in groundwater from the area (spring water measurements), with two pe- riods of higher water discharge in the spring and autumn, and low or no discharge (dry springs) in the summer. The temperatures of both the ground- water and the Učja River are lower in winter (min 3.6 ºC) and higher in summer (max 18.7 ºC). The EC values indicate a highly permeable carbonate aquifer with a low residence time. The f luctuation of specific electrical conductivity at all sampling sites throughout the year refelects depletions dur- ing the dry season and higher values in spring (March-April) and autumn (November-December) and are related to periods of snow and rain. Slight differences in physico-chemical parameters were observed between sampling sites of higher and lower elevations. All water samples indicate the same Ca-Mg- HCO3 facies, with the most abundant ions Ca 2+, Mg2+, and HCO3 –, and low concentrations of K+, Na+, Cl-, NO3 -, and SO4 2+. Differences in concentra- tions of Ca2+ and Mg2+ and of the Mg2+/Ca2+ molar ratio between the two groups of springs are ob- served. The limestone defines the recharge area for the first group of springs (UC1, UC2, UC11), while the dolomite prevails in the second group of springs (UC3-UC8, UC12). The Mg2+/Ca2+ molar ratios for UC9 (Učja River) and UC12 (within the Idrija Fault zone) are rather higher than for first group of springs. The pH values (average 8.12) also indicate the rather alkaline waters character- istic of carbonate aquifers. The hydrogen (δ2H) and oxygen (δ18O) isotope values suggest the complex mixing of maritime and continental air masses. The isotopic compo- sition of Učja groundwater ref lects its proximity to the Mediterranean climate and to some degree the inf luence of continental precipitation as well. Minor depletions in the altitude isotopic effect are noted (0.11 ‰ per 100 m for δ18O and 0.45 ‰ per 100 m for δ2H) at sampling locations from springs at higher altitudes (UC1, UC2, UC11) compared to those springs at lower altitudes (UC3-UC8, UC12). The altitude isotopic effect varies between seasons and is most prominent in spring. The δ13CDIC val- ues indicate the dissolution of carbonates and the degradation of organic matter. The results contribute to a considerably better understanding of the aquifer recharge area, the or- igin of the water, and groundwater dynamics, and provide us with an important basis for a compre- hensive interpretation of a potential natural water resource in the future. Acknowledgments The research was financial supported by the Slove- nian Research Agency (ARRS) within the postdoctoral project Z1-8154 (Evaluation of Učja Valley karstic aq- uifer as a potential source of drinking water (NW Slo- venia) and research programme P1-0195 (Geoenviron- ment and geomaterials). The results of this study have been discussed within the COST Action: “WATSON” CA19120 (www.cost.eu). Special thanks to all my col- leagues for their assistance in the f ieldwork performed (A. Grkman, B. Miklavič, D. Rehakova, B. Rožič, T. Ver- bovšek), to M. Švob, and B. Rožič for their preparation of the cartographic images, and to Jeff Bickert for his copy edit of the text. References ActLabs, 2023: Tools for buried deposit targets, Hydrogeochemistry. Available online: https:// ac t l ab s .c om/ge o c hem i s t r y/to ol s - for - bu r - ied-deposit-targets/hydrogeochemistry/ (20. 10. 2023). Aggarwal, P.K., Froehlich, K.F. & Gat, J.R. 2005: Isotopes in the Water Cycle. 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CC Atribution 4.0 License Signs of crustal extension in Lower Jurassic carbonates from central Slovenia Znaki ekstenzije skorje v spodnjejurskih karbonatih osrednje Slovenije Luka GALE1,2 & Boštjan ROŽIČ2 1Department of Geology, University of Ljubljana, Aškerčeva 12, SI–1000 Ljubljana, Slovenia; e-mail: luka.gale@ntf.uni-lj.si; bostjan.rozic@ntf.uni-lj.si 2Geological Survey of Slovenia, Dimičeva ulica 14, SI– 1000 Ljubljana, Slovenia; e-mail: luka.gale@geo-zs.si Prejeto / Received 7. 8. 2023; Sprejeto / Accepted 27. 2. 2024; Objavljeno na spletu / Published online 29. 3. 2024 Key words: carbonate platform, External Dinarides, Early Jurassic, Podbukovje Formation, neptunian dyke, breccia Ključne besede: karbonatna platforma, Zunanji Dinaridi, zgodnja jura, Podbukovška formacija, neptunski dajk, breča Abstract The Lower Jurassic Podbukovje Formation represents a succession of shallow marine carbonate rocks deposited on the former Southern Tethyan Megaplatform and one of its successors, the Adriatic Carbonate Platform. Several outcrops of the Podbukovje Formation from central Slovenia (southern margin of the Ljubljana Moor) are presented, bearing possible evidence of Early Jurassic extensional tectonics. Peritidal facies of the lowermost, Hettangian – Sinemurian, part of the Podbukovje Formation locally interfingers with bodies of matrix supported pervasively dolomitized polymictic breccia, several metres to tens of metres thick and is locally cut by neptunian dykes some few decimetres to metres wide. The same or slightly younger part of the formation locally contains grabens/half- grabens metres to tens of metres deep and filled with poorly sorted pervasively dolomitized matrix supported polymictic breccia. Small miliolid foraminifera are present within the clasts and in the matrix. Finally, partly dolomitized blocky breccia tens of metres thick locally overlies the Pliensbachian – lowermost Toarcian limestone with lithiotid bivalves. Besides completely and partly dolomitized clasts, the breccia contains a variety of limestone clasts and preserves common radial ooids and some bioclasts within the partially dolomitized matrix. The Hettangian-Sinemurian breccias and dykes are presumably related to the early, diffused rifting stage of the Penninic (Alpine Tethys) Ocean, whereas Toarcian breccias relate to the main, focused rifting stage. Together with evolving biota and changing paleo-oceanographic conditions, the extensional tectonics may have been an important factor behind the facies changes observed within the Podbukovje Formation. Izvleček Spodnjejurska Podbukovška formacija predstavlja zaporedje plitvomorskih karbonatnih kamnin, odloženih na nekdanji Južnotetidini karbonatni megaplatformi in Jadranski karbonatni platformi. V članku predstavljamo nekaj izdankov Podbukovške formacije iz osrednje Slovenije ( južni rob Ljubljanskega barja), v katerih so vidni možni dokazi za zgodnjejursko ekstenzijsko tektoniko. Periplimski facies najnižjega, hettangijsko-sinemurijskega dela Podbukovške formacije se lokalno prepleta z nekaj metri do nekaj deset metri debelimi plastmi muljasto podprte povsem dolomitizirane polimiktne breče. Drugod plasti periplimskih karbonatov sekajo neptunski dajki, ki so široki do nekaj metrov in zapolnjeni z dolomikritom. Isti ali nekoliko višji deli formacije ponekod vsebujejo tektonske grabne/polgrabne, zapolnjene z nekaj metri ali desetinami metrov povsem dolomitizirane slabo sortirane, muljasto podprte polimiktne breče. V klastih in vezivu so prisotne drobne miliolidne foraminifere. Delno dolomitizirana blokovna breča je prisotna tudi v zgornjih delih Podbukovške formacije nad pliensbachijsko – spodnjetoarcijskim litiotidnim apnencem. Poleg povsem in delno dolomitiziranih klastov breča vsebuje tudi raznolike klaste apnenca. V vezivu so prisotni radialno žarkoviti ooidi in nekaj bioklastov. Hettangijsko–sinemurijske breče in dajke povezujemo z zgodnjo, razpršeno fazo razpiranja Peninskega oceana (Alpske Tetide), toarcijske breče pa z glavno, fokusirano fazo razpiranja. Ekstenzijska tektonika je skupaj z razvojem biote in spremembami v paleo-oceanografskih razmerah pomembno vplivala na faciesne spremembe med nižjimi in višjimi deli Podbukovške formacije. GEOLOGIJA 67/1, 25-40, Ljubljana 2024 https://doi.org/10.5474/geologija.2024.002 26 Luka GALE & Boštjan ROŽIČ Introduction The Late Triassic to Early Jurassic paleogeog- raphy of central Pangea and the western Tethys Ocean was greatly affected by the opening of the Central Atlantic and related systems of basins belonging to the Penninic Ocean (Ratschbacher et al., 2004; Meschede & Warr, 2019). The main rifting phase started during or at the end of the Pliensbachian and into the Toarcian, and is re- f lected in the Southern Alps in the subsidence and eventual drowning of smaller platform areas, to- gether with the establishment of marine plateaus (Buser, 1989; Bosellini, 2004; Šmuc, 2005; Ber- ra et al., 2009; Rožič & Šmuc, 2009; Šmuc, 2010; Rožič et al., 2014). The main rifting event was preceded by a phase of diffuse early rifting, which occurred from the late Hettangian to the Sinemu- rian. In the western and central Southern Alps, this phase is manifested through the subsidence of the Lombardian and Belluno basins (Winterer & Bosellini, 1981; Bertotti et al., 1993; Sarti et al., 1993; Clari & Masetti, 2002; Berra et al., 2009), whereas accelerated subsidence, increase in slope inclination, segmentation, and block tilting have been documented in the basin areas in the eastern Southern Alps (Rožič et al., 2017). In the External Dinarides, major shifts in car- bonate platform facies were described from the uppermost Pliensbachian – Toarcian successions (Dragičević & Velić, 2002; Črne & Goričan, 2008; Sabatino et al., 2013; Martinuš & Bucković, 2015; Ettinger et al., 2021), but the earlier tectonic events are not as well documented and their inf luence on the evolution of the platform has not yet been ful- ly evaluated (Dozet & Strohmenger, 1996; Knez et al., 2003). Fig. 1. Location and geological map of the study area. a: Outline of Slovenia. Position of the area, shown in Fig. 1b is indicated by a black rectangle. b: Detailed map and geological map of the studied area. Position of the described outcrops 1–4 (see text and Table 1) is indicated by the circled numbers 1–4. Geological map (Buser et al., 1967; Buser, 1968) is drawn over the LIDAR digital model of the relief, 2015. Data source: Slovenian Environment Agency. Accessed via portal Geopedia (Sinergise d.o.o.) in May 2023. 27Signs of crustal extension in Lower Jurassic carbonates from central Slovenia The aim of this paper is to present possible ev- idence for the Early Jurassic extensional tectonics in the area of the present-day External Dinarides (central Slovenia) related to both tectonic phases mentioned above. We suggest that Early Jurassic extensional tectonics was an important force be- hind the transition from the Hettangian facies as- sociation of intertidal f lats to the Sinemurian and Pliensbachian shallow lagoon and shoal facies. Geological Setting The presented successions of Lower Jurassic rocks deposited in the shallow marine environ- ments of the Southern Tethyan Megaplatform (sensu Vlahović et al., 2005). During the late Ear- ly Jurassic, this large entity broke up into several smaller (but still relatively large) carbonate plat- forms, one of which was the Adriatic Carbonate Platform, which extended from present-day NE Italy to Montenegro and Albania (Dragičević & Velić, 2002; Vlahović et al., 2002, 2005). To the north (present orientation), the platform faced the Slovenian Basin (Buser, 1989, 1996). The Adriat- ic Carbonate Platform was separated from other platform areas to the west through the formation of the Adriatic Basin that connected the Belluno and the Ionian Basins (Vlahović et al., 2005). The presented outcrops are located in central Slovenia, on the southern rim of the Ljubljana Moor Ba- sin (Fig. 1). Structurally, the area belongs to the Hrušica Nappe of the External Dinarides (Placer, 1999), and is dissected by major SSE-NNW direct- ed dextral strike-slip and associated faults (Buser et al., 1967; Pleničar, 1970; Buser, 1968, 1974). The Lower Jurassic succession has been as- signed to the Podbukovje Formation and subdi- vided into four to five members (Fig. 2) (Dozet & Strohmenger, 2000; Dozet, 2009; Brajkovič et al., 2022). The lowermost Krka Limestone Member rep- resents bedded intertidal limestone and dolostone (Dozet, 1993). According to Gale (2015), and Gale and Kelemen (2017), Lofer-type cycles of the Het- tangian part of this member upwards pass into pre- dominantly subtidal micritic and oolitic limestone. The following Orbitopsella Limestone Member is dominated by thick-bedded limestone in which fo- raminifera Orbitopsella first occurs. Breccia, on- coid, gastropod, and megalodontid limestone beds are sporadically present (Dozet, 2009). The follow- ing Lithiotis Limestone Member contains variety of facies types, deposited under restricted subtidal and intertidal conditions. Lithiotid bivalves occur at several levels and are a distinctive feature of this member (Dozet, 2009). The next, Oolitic Limestone Fig. 2. Lithostratigraphic units of the Lower Jurassic car- bonates of central Slovenia and approximate stratigraphic posi- tion of the presented outcrops. Schemes for Suha Krajina and for Radensko Polje are drawn after Dozet and Strohmenger (2000) and Dozet (2009), re- spectively. The lithological units from the Mt. Krim area are modified after Gale (2015). 28 Luka GALE & Boštjan ROŽIČ Member is characterised by oolitic limestone fa- cies (Dozet & Strohmenger, 2000; Dozet, 2009). The Podbukovje Formation ends with the Spotted (or Spotty) Limestone Member, representing suc- cession of thin to medium thick beds of dark grey limestone of nodular-like appearance. Limestone is mostly micritic (Dozet, 2009). Previous records of Lower Jurassic breccias in southern Slovenia Although it remains valid to this day that the Lower Jurassic platform carbonates of the southern Slovenia show little or no evidence of Early Juras- sic extension, there are a few mentions of breccias that could be related to palaeotectonics. Breccias positioned atop the Upper Triassic Main Dolomite Formation were mentioned from the vicinity of Logatec (Buser, 1965). Ogorelec and Rothe (1993) described breccias at the boundary between the Upper Triassic platform carbonates and Jurassic deposits in the Čepovan-Lokovec section. Blocky breccias exceed 10 m or 20 m in thickness and laterally pinch-out. Fragments of corals within the breccia indicate earliest Jurassic age. Knez et al. (2003) described poorly sorted (clasts ranging in size from very fine pebble to boulder), chaot- ic, matrix- and clast-supported dolomitic breccia discordantly lying on peritidal carbonates. No fos- sils were found, but based on the superposition the breccia was formed close to the Triassic-Jurassic boundary. Authors interpreted breccia as “synsed- imentary, fault, f issure, or small graben-related, tectonically inf luenced phenomenon” (Knez et al., 2003, p. 34–35). From younger beds, Buser (1965, 1974) mentioned limestone breccia beds alternat- ing with light grey lower and middle Lower Juras- sic limestone in the area between Ivančna Gorica and Trebnje. Lithiotid bivalves have been found in some of the limestone beds, indicating that the sedimentation of breccias lasted up to the Pliens- bachian (Buser, 1974). Upper Lower Jurassic to Middle Jurassic dolomitic breccias were also docu- mented between Velika Gora and Loški Potok (Bus- er, 1965). Breccias were also illustrated in a sche- matic column of middle Lower Jurassic (?) beds at Korinj, but not explained in detail (Strohmenger & Dozet, 1991). Finally, from the area of Mt. Krim studied herein, Miler and Pavšič (2008) described breccias within the Hettangian and Sinemurian, as well as the Pliensbachian and the Toarcian parts of the succession. The thickness of the breccia beds is not indicated, but the authors mention up to 15 cm large clasts in Toarcian breccias, which have wackestone matrix containing ooids and bioclasts, including miliolid foraminifera. Methods and materials The sections of Lower Jurassic shallow marine carbonates presented herein were investigated be- tween the years 2014 and 2022. The sections are situated along roads or hiking trails. The strati- graphic thickness of the studied successions varies from a few metres to several tens of metres and is indicated in the Results sections. For the purpose of petrographic description, 63 samples of rock were cut for thin sections of 28 × 47 mm in size. Thin sections were investigated with a polarizing mi- croscope. Carbonates were classified according to Dunham (1962), and Embry and Klovan (1971). In forming the textural name, we follow recommen- dations by Wright (1992) putting the predominant component first. Fifteen thin sections of breccias and the surrounding rock were stained with Aliza- rin Red S dye in order to determine the presence of dolomite. The texture of the dolomite was described in accordance with Sibley and Gregg (1987). Al- though the term “dolostone” has not gained wide usage among sedimentary petrologists, we use this term here to distinguish dolomitic rock from the mineral dolomite (see also Warren, 2000, p. 7). Results The examined outcrops are presented according to superposition. The coordinates of the sections are given in Table 1. Due to the presence of stromat- olites, herein presented outcrops 1–3 and the lower part of the section 4 lithostratigraphically belong to the lowermost, Krka Member. Breccias overly- ing the Lithiotid Limestone Member in the upper part of the section 4 are likely positioned lateral to the lower part of the Spotted/Spotty Member sensu Dozet and Strohmenger (2000) and Dozet (2009). Locality Stratigraphic position Latitude Longitude Pijava Gorica (Outcrop 1) Krka Limestone Member (Hettangian) 45°56’40.29’’ N 14°34’17.68’’ E Tomišelj (Outcrop 2) Krka Limestone Member (Sinemurian) 45°57’46.69’’ N 14°28’19.15’’ E Strahomer (Outcrop 3) Krka Limestone Member (Sinemurian) 45°56’57.24’’ N 14°28’0.86’’ E Mt. Krim (Outcrop 4, lower) Krka Limestone Member (Hettangian) 45°55’16.31’’ N 14°28’38.02’’ E Mt. Krim (Outcrop 4, upper) Unnamed member (Toarcian) 45°55’38.72’’ N 14°28’28.90’’ E Table 1. "Coordinates of the presented outcrops and sections." 29Signs of crustal extension in Lower Jurassic carbonates from central Slovenia Fig. 3. Field view of the outcrops 1–3. a: Neptunian dykes cutting through Lower Jurassic dolostone at Pijava Gorica (outcrop 1). b: Clasts of dolostone floating in dolomicrite filling the Neptunian dykes at Pijava Gorica (outcrop 1). c–c’: Base of the matrix-supported dolomitic breccia in outcrop 2 above Tomišelj (lower 4 m of sedimentary log in Fig. 4). d: Eastern side of the outcrop of dolomitic breccia at the roadcut between the Sleme, Strmec, and Trešenk summits west of Strahomer (outcrop 3). Yellow lines indicate the position of a paleo-fault plane (left side) and the bedding plane separating the breccia from the overlying stromatolitic dolomite. e: Western side of the outcrop depicted in Figure 3d. Yellow line indicates the position of the upper bedding plane of breccia. f: Hand sample of matrix-supported dolomitic breccia from outcrop 2. Note the different colours of clasts and that some clasts (left side of the sample) themselves are matrix-supported breccia. g: Hand sample of Toarcian breccia, outcrop 4 (upper). 30 Luka GALE & Boštjan ROŽIČ Outcrop 1: Neptunian dykes within the Krka Limestone Member at Pijava Gorica (Hettangian – ?Sinemurian) The roadcut between Pijava Gorica and Smr- jene exposes medium thick-bedded dark grey do- lostone (dolomicrite). The section is crossed by numerous smaller faults, and the bedding orien- tation changes, so the actual thickness of the suc- cession cannot be determined. Planar laminations (stromatolites) are locally visible. The dolostone is crosscut by dykes filled with darker dolostone (do- lomicrite), which locally contains angular clasts of dolostone lithologically identical to the surround- ing rock (Fig. 3a–b). The size of clasts ranges from 5 mm to 50 cm. Some of the clasts closely fit to- gether, indicating very short transport, while oth- ers f loat within the matrix. Outcrop 2: Syndepositional breccia within the Krka Limestone Member above Tomišelj (Hettangian – Sinemurian) Dolomitized matrix-supported carbonate con- glomeratic breccia with characteristic brown- ish-grey matrix is found at several localities around Mt. Krim. However, due to the intense weathering of the dolostone and the dense vegeta- tion, outcrops with visible relationships with the surrounding lithologies are difficult to find. Dol- omitic breccia a few metres thick was discovered roughly west of Tomišelj along a forest road run- ning along the eastern slopes of the small summits Gadna (elevation 521 m) and Srobotnik (elevation 603 m) (Fig. 1). The described section is approximately 10 m thick (Fig. 4). It starts with thin to thick beds of light grey dolostone (dolosparite and dolomicrite). Stromatolites and desiccation cracks are present in dolomicrite. Upwards (immediately below the breccia level) lies a bed of light grey dolostone 140 cm thick with stromatolite intraclasts in its lower part. The described beds dip at 240/55 and laterally end at a steep scarp, interpreted as a nor- mal paleofault (Fig. 3c). The succession continues with pervasively dolomitized conglomeratic brec- cia, which covers the paleofault and fills the gra- ben. The breccia is matrix-supported and at least 4.5 m thick within the graben. The clasts vary in colour and are angular to subrounded. Some are shattered into mosaic-like configurations. Clast dimensions decrease upwards: close to the paleofault they measure up to 15 cm, while they are up to 2 cm large near the top of the breccia. In the graben-filling succession (basinward sen- su Matenco & Haq, 2020), the breccia is followed by several thinner and possibly internally lay- ered beds of pervasively dolomitized fine-grained polymict breccia. The clasts in this fine-grained breccia consist of crystalline dolostone, as well as completely dolomitised calcimudstone, peloi- dal-bioclastic packstone, and bioclastic packstone, transitioning to calcimudstone. Dolomitized bio- clastic packstone is relatively abundant in miliolid foraminifera (Fig. 5a–b, e). The same foraminif- era can also be found within the finely crystalline dolomitized breccia matrix, indicating the same/ similar age of the matrix and (at least part of ) the clasts. Sinemurian foraminifera were deter- mined from beds lying approximately 60 strati- graphic metres higher in the succession (section “Tomišelj 1” in Gale & Kelemen, 2017). Fig. 4. Sedimentary log of the breccia body within the Lower Juras- sic (Hettangian?) Krka Limestone Member above Tomišelj (outcrop 2). Numbers to the right indicate thin section numbers. Outcrop 3: Matrix-supported dolomitic breccia within the Krka Limestone Member west of Strahomer (Hettangian – Sinemurian) Roadcuts between the Sleme, Strmec, and Trešenk summits west of Strahomer feature long exposures of pervasively dolomitized matrix-sup- ported breccia, macroscopically identical to the breccia in outcrop 2, described above. At the east- ern (lowermost) side of the outcrop bedded light grey dolostone (dolosparite and dolomicrite with rare fenestrae) is exposed (Fig. 3d). The bedded 31Signs of crustal extension in Lower Jurassic carbonates from central Slovenia Fig. 5. Selected foraminifera from the described outcrops. a–b: Miliolid foraminifera (?Istriloculina sp.). Outcrop 2. Thin section 1895. c–d: Miliolid foraminifera (?Istriloculina sp.). Outcrop 3. Thin section 1903. e: Undetermined foraminifera. Outcrop 2. Thin section 1895. f: Various foraminifera in ooids (Trocholinidae and Miliolida) and as free particles (?Ammobaculites or ?Everticyclammina sp.). Outcrop 4 (upper). Thin section 1927. g: Trocholinidae (cf. Trocholina conica (Schlumberger).). Outcrop 4 (upper). Thin section 1927. h: Trocholinidae (cf. Trocholina conica (Schlumberger).). Outcrop 4 (upper). Thin section 1920. i: Trocholinidae (cf. Coscinoconus alpinus Leupold in Leupold and Bigler). Outcrop 4 (upper). Thin section 1933. j: Coscinoconus sp. Outcrop 4 (upper). Thin section 1916. k–m: Socotraina serpentina Banner, Whittaker, BouDagher-Fadel and Samuel. Outcrop 4 (upper). Thin section 1930. n: Sessile foraminifera on radial ooids. Outcrop 4 (upper). Thin section 1932. o: ?Ammobaculites sp. Outcrop 4 (upper). Thin section 1914. p: Meandrovoluta asiagoensis Fugagnoli and Rettori. Outcrop 4 (upper). Thin section 1911. 32 Luka GALE & Boštjan ROŽIČ dolostone dips at 300/25. The beds are truncat- ed along a subvertical (120/80) plane, a possible palaeofault that separates the bedded dolostone from the breccia. The matrix-supported to locally clast-supported breccia is poorly exposed and at- tains a thickness of at least 25–30 m. Clasts with- in the breccia are very poorly sorted (Fig. 3f–g). On average, they form approximately 20 % of the rock, but are more abundant near the mentioned paleofault. The clasts are generally a centimetre in size, but the size of the clasts varies consider- ably between the samples. The largest recorded clasts measure approximately 15 cm, while the smallest are less than 0.2 mm in size. Macroscop- ically, they are white, greyish-brown, and brown laminated dolomicrite. At the microscopic level, the following lithoclasts can be distinguished: dolomitic tectonic breccia, crystalline dolostone, pervasively dolomitized lithoclasts with recognis- able primary composition of mudstone, fenestral mudstone, laminated mudstone (stromatolite), pe- loidal wackestone, bioclastic-peloidal wackestone and packstone, and intraclastic grainstone. Clasts are angular to subrounded, and highly variable in shape. No connection between lithological com- position and roundness was noted. The matrix is brownish dolomicrite. Small benthic foraminifera are rare, both within the clasts and in the matrix (Fig. 5c–d). The breccia is crosscut by younger veins, up to 2 cm thick and filled with dolomitic cement. At the opposite, western side of the roadcut the breccia at the top laterally and vertically pass- es into bedded light grey dolostone (dolosparite) and laminated dolostone (dolomicrite) (Fig. 3e). Small-scale cracks, f illed with black dolomicrite (seemingly identical to the neptunian dykes in outcrop 1), are present within beds of light grey dolosparite overlying the breccia. Outcrop 4 (lower part): Dolomitic breccia within the Krka Limestone Member on the NE slope of Mt. Krim (Hettangian-Sinemurian) A thick succession of pervasively dolomitized breccia is exposed within a 280 m long succes- sion underlying Sinemurian and Pliensbachian limestone on the hiking path from Gornji Ig to Mt. Krim. The area was covered also by a detailed ge- ological map of Miler and Pavšič (2008), where the same breccias are brief ly described. The succes- sion was logged schematically because of the poor visibility of bed boundaries (Fig. 6). The lower 100 m of the succession is represented by bedded dolostone, in which stromatolites, birdseyes fenes- trae, stromatolitic intraclasts, and black pebbles Fig. 6. Stratigraphic succession of Lower Jurassic (Hettangian – Toarcian) beds on the NE slope of Mt. Krim (all of outcrop 4). Num- bers to the right indicate thin section numbers. 33Signs of crustal extension in Lower Jurassic carbonates from central Slovenia are locally present. Fractures filled with dark do- lostone (dolomicrite) resembling neptunian dykes from outcrop 1, were noticed in the upper part of this interval. The next 50 m of the succession is dominated by chaotic and poorly sorted dolomitic breccias, deposited in beds 3–17 m thick. Breccia is clast or matrix-supported, with clasts ranging from 1 mm to at least 30 cm in size. The average clast size is approximately 5 cm. Clasts are angu- lar to rounded, dolomicritic or dolosparitic, and of different colours. The section continues upwards with thick to massive beds of dolostone, with a single bed of dolomitic breccia at 190 m of the suc- cession. At approximately 290 m of the succession, the dolostone is succeeded by bedded limestone. The lower part of the limestone succession roughly corresponds to the Orbitopsella Limestone Member (although Orbitopsella f irst occurs approximately 30 m above the first limestone bed). The lowest occurrence of the lithiotid bivalves, 41 m above the base of the limestone part of the section, defines the base of the approximately 85-m-thick Lithiotid Limestone Member (Fig. 6). Within the limestone interval, oolitic and bioclastic limestones predom- inate, with bioclasts becoming more common in the Lithiotid Limestone Member. Micritic lime- stone is subordinate. Beds are between 5 cm and 160 cm thick. Small-scale neptunian dykes are lo- cally present within this member. Outcrop 4 (upper part): Dolomitized blocky breccia overlying the Lithiotid Limestone Member on the NE slope of Mt. Krim (Toarcian) After the highest occurrence of the lithiotid bi- valves, a few beds of nearly black limestone (intr- aclastic-bioclastic grainstone with oncoids) follow. Foraminifera Haurania deserta Henson is numer- ous in some beds, while ?Bosniella oenensis Gušić and Involutina liassica (Jones) are less common. According to Velić (2007), the stratigraphic range of H. deserta is from the late Sinemurian to the end of the Pliensbachian, and B. oenensis is limited to the Pliensbachian. Other bioclasts are fragments of bivalve shells, gastropods, calcimicrobes, mi- croproblematica Thaumatoporella, echinoderms, and dasycladacean algae. Limestone is followed by poorly exposed dolos- tone (dolosparite) with small lithoclasts overlain by one or several beds (this part of the section is mostly covered) of very poorly sorted, coarse- grained partly dolomitized polymictic breccia (Figs. 3g, 6). Clasts are rounded to angular, and on average 3–5 cm large. The largest clasts are up to 30 cm in size. Some clasts completely escaped dol- omitization or are only partially dolomitized (mud- stone, bioclastic wackestone, oolitic grainstone, pelletal grainstone, bioclastic-intraclastic-oolitic grainstone, peloidal-oolitic-crinoidal grainstone, peloidal-bioclastic grainstone, peloidal grain- stone, and lithoclastic-bioclastic rudstone), while the others are completely replaced by dolomite and rarely show their original texture and composition (one exception being oolitic grainstone, mimeti- cally replaced by coarse, planar-s dolomite). The lithoclastic-bioclastic rudstone clasts contain So- cotraina serpentina Banner, Whittaker, BouDagh- er-Fadel, and Samuel (Fig. 5k–m), Siphovalvulina sp., Meandrovoluta asiagoensis Fugagnoli & Ret- tori, and Haurania deserta Henson. Trocholinidae (Fig. 5f–j), Miliolida, and Pseudopfenderina were determined from other clasts. Besides the litho- clasts, non-dolomitized radial ooids, fragments of corals, sponges, gastropods, and echinoderms are present in the dolomitized matrix of the breccia. Some ooids formed around tests of foraminifera Miliolida and ?Siphovalvulina. Poorly sorted breccias are followed by poorly exposed dolostone (dolosparite), followed by thin- to medium thick-bedded, almost black limestone (oolitic wackestone, packstone and grainstone, mudstone, rare spiculitic packstone, and bioclas- tic-pelletal packstone). Ooids are of the radial type. Skeletal material is relatively rare: echino- derms, gastropods, bivalves, ostracods, pelagic crinoids, foraminifera, sponge spicules, and cal- careous spheres (radiolarians?) are present. Fo- raminiferal assemblage comprises common agglu- tinated sessile forms (Fig. 5n), ?Ammobaculites sp. (Fig. 5o), Meandrovoluta asiagoensis Fugagnoli & Rettori (Fig. 5p), Ophthalmidium sp., Lenticulina sp., nodosariids, Textulariida, and Epistominidae. The section ends with bedded dolostone. For the breccia described above, Toarcian age is assumed. This is supported by the findings of S. serpentina, which was described from the up- per Lower Jurassic (Toarcian) beds (Banner et al., 1997; Martinuš & Bucković, 2015; BouDagh- er-Fadel, 2018). Based on the presence of M. asia- goensis with the stratigraphic range from Sinemu- rian to Toarcian (Velić, 2007), Toarcian age is also presumed for the oolites overlying the breccia. Dolomitization Although all of the breccias described above show some degree of dolomitization, there are some notable differences between the Hettangian-Sine- murian and the Toarcian breccias. The Hettangi- an-Sinemurian breccias from outcrops 2, 3, and 4 (lower part) are completely (pervasively) dolo- mitized (Fig. 7a–b). Non-mimical dolomitization 34 Luka GALE & Boštjan ROŽIČ Fig. 7. Dolomitization of Lower Jurassic breccias. All pictures are from the stained parts of the thin sections. a: Pervasive dolomitization of clasts and matrix. Thin section 1903; outcrop 3; Sinemurian. b: Pervasive dolomitization of clasts and matrix. Most dolomite in the clasts is non-mimic, subhedral. Thin section 1906; outcrop 3; Sinemurian. c: Different degrees of dolomitization of breccia. Some clasts are undolo- mitized (1), others partly dolomitized with euhedral rhomboidal dolomite (2), and some non-mimically replaced by subhedral dolomite (3). The breccia matrix is mostly dolomitized. Thin section 1921; outcrop 4 (upper); Toarcian. d: Mimical dolomitization of oolitic grainstone. Outlines of ooids is indicated by the arrowhead. Thin section 1915; outcrop 4 (upper); Toarcian. e: Partial dolomitization of breccia, with undolomitized (1) and completely dolomitized clasts (2). Thin section 1916; outcrop 4 (upper); Toarcian. f: Partial dolomitization of breccia. Mimical (1) and non-mimical (2) dolomitization of clasts. Thin section 1916; outcrop 4 (upper); Toarcian. crystalline and mimically replaces fine-grained calcimudstone. Pervasive mimical dolomitization by very small crystals of dolomite was also recog- nized in peloidal grainstone and laminated (stro- matolitic) dolomicrite. The matrix of the Hettangi- an-Sinemurian breccias is non-mimically replaced by equigranular, rarely polymodal, anhedral (?) to subhedral dolomite. of the clasts includes the growth and replacement of original textures by medium (0.025 mm) to coarse (0.330 mm) subhedral dolomite crystals of equal or different sizes (unimodal or polymodal). Other clasts show mimical replacement by very small subhedral dolomite. Staining with Aliz- arin Red S revealed that micritic clasts are also composed of dolomite, which is thus very finely 35Signs of crustal extension in Lower Jurassic carbonates from central Slovenia In contrast, Toarcian breccia shows only par- tial dolomitization (Fig. 7c–f). Some of the clasts are completely devoid of dolomitization or are only partly dolomitized. These are calcimudstone (partially dolomitized clasts show non-mimical growth of euhedral, rhombic dolomite crystals), peloidal packstone, and bioclastic wackestone. Oo- litic grainstone is present in a non-dolomitized as well as completely dolomitized variety. The latter comprises mimical replacement by coarse subpla- nar dolomite. Completely dolomitized clasts in- clude non-mimical, unimodal, subhedral dolomite, and polymodal, non-mimical subhedral dolomite. The matrix of the breccia is partially or completely dolomitized, non-mimically replaced by euhedral crystals of dolomite of different sizes (polymod- al), or by both, subplanar and euhedral crystals of dolomite. Discussion Interpretation of described outcrops The outcrops described above contain two types of sedimentary bodies that are here inter- preted as evidence for extensional tectonics: (1) neptunian dykes, and (2) breccias associated with palaeofaults. Neptunian dykes are “sedimentary dykes and sills formed by sediment f illing of submarine f is- sures or cavities” (Lehner, 1991, p. 593). They can be “caused by extensional movement of lith- if ied and indurated sediment due to gravitation- al mass movement or differential tectonic move- ment” (Lehner, 1991, p. 593). Alternatively, open spaces could be created by dissolution by mete- oric waters during the emergence of the platform (Winterer et al., 1991). Early Jurassic tectonics was advocated as a possible cause for the forma- tion of the neptunian dykes cutting through the shallow platform deposits of the former Trento Platform in the Sasso Rosso region in Trentino, northern Italy (Lehner, 1991), and for the dykes transecting the Upper Triassic and Lower Juras- sic peritidal facies of the Julian Carbonate Plat- form in the Julian Alps, Slovenia (Babić, 1981; Šmuc, 2005; Črne et al., 2007). These last are dated as probably Pliensbachian in age (Črne et al., 2007). Small-scale neptunian dykes have also been recognized in Sinemurian limestone from the vicinity of Ig, but they are f illed with intra- clastic-bioclastic packstone containing Upper Ju- rassic microfossils (Rožič et al., 2018). Evidence of neptunian dykes and sills is unambiguous in outcrop 1. No fossils were found in the infill of neptunian dykes at Pijava Gorica. Based on lo- cally derived clasts that are barely detached from the sides of the dykes and sills, we assume that their age is similar to that of the host rock, i.e. Hettangian – ?Sinemurian in age. In the case of outcrops 2 and 3, it seems that breccia deposited along fault-scarps. Combining the existence of paleo-scarps and the large thick- ness of the breccia in outcrops 2 and 3, interpre- tation of this as intraformational breccia related to subaerial exposures and the Lofer cycle-type of sedimentation can be excluded. Instead, breccias deposited at the base of the scarp, which itself was created by a normal fault in the form of submarine talus (see Mišík et al., 1994; Ruiz-Ortiz et al., 2004; Aubrecht & Szulc, 2006; Ortner et al., 2008). The matrix-supported nature of the breccia suggests deposition from submarine debris f lows (Fig. 2 in Ribes et al., 2019), rather than via collapse of the footwall (Ortner et al., 2008). As described above, the breccia from outcrop 2 is of Sinemurian age or slightly older. Seemingly the same miliolid fo- raminifera were found in the clasts and matrix of breccias from outcrops 2 and 3, so Hettangian – Sinemurian age is also assumed for the latter too. In the section below the summit of Mt. Krim (out- crop 4), carbonate breccias occur below as well as above the Lithiotid Limestone Member. The first breccia is lithologically identical to the breccia re- corded in outcrops 2 and 3, but the geometry of the breccia could not be determined, nor were any palaeofaults identified. The breccia overlying the Lithiotid Limestone Member clearly differs from the above mentioned breccias in age, in the composition of the clasts and matrix, in the manner of dolomitization, and in their being under- and overlain by subtidal car- bonates. Here also, the geometry of the breccia body is not determined due to the vegetative cover of the area. However, the variety of clasts, which are mixed with ooids, sponge and coral fragments, derived from an active carbonate platform sug- gests that this too could be scarp breccia. The late Pliensbachian – Toarcian extension is clearly manifested in the partial disintegration of the north-eastern margin of the Southern Tethyan Megaplatform margin (Dragičević & Velić, 2002), the deepening of some other areas of the same plat- form (Masetti et al., 2012; Sabatino et al., 2013; Ettinger et al., 2021), and the break-up and par- tial subsidence of the Julian Carbonate Platform (Šmuc, 2005; Šmuc & Goričan, 2005; Rožič et al., 2014; Gale et al., 2021). The effects of the earli- er, Hettangian–Sinemurian extensional tectonics on the Southern Tethyan Megaplatform, are less clear, since the tectonics coincide with eustatic 36 Luka GALE & Boštjan ROŽIČ sea-level changes (Haq et al., 1988; Hallam, 2001), as well as the recovery of skeletal-carbonate pro- ducing biota after the biotic crisis at the Triassic/ Jurassic boundary (Hallam, 1996; Barattolo & Ro- mano, 2005; Damborenea et al., 2017). Neverthe- less, we hypothesise that the extensional tectonics, through the establishment of rugged palaeotopog- raphy, played an important role in the recorded fa- cies changes (see Ruiz-Ortiz et al., 2004; Lachkar et al., 2009). This tectonic phase may potentially coincide with the subsidence of the margin, the in- creased sedimentation of the slope sediments, and the tilting of tectonic blocks in the Slovenian Basin (Rožič et al., 2017). Timing and style of dolomitization Despite the differences in the completeness of dolomitization (pervasive dolomitization of the Hettangian-Sinemurian breccia, and the partial dolomitization of the Toarcian breccia), subhe- dral and euhedral dolomite textures predomi- nate in both cases. Planar dolomite forms early during diagenesis at temperatures below 50 °C (Gregg & Sibley, 1984; Warren, 2000), so an early diagenetic dolomitization is assumed for both types of breccia. Early, even penecontemporaneous dolomiti- zation has been postulated for the lowermost Ju- rassic peritidal dolomites of the Mt. Krim area (Ogorelec, 2009), as well as for analogous Upper Triassic dolomites from Slovenia and Hungary (Ogorelec & Rothe, 1993; Haas & Demény, 2002; Haas et al., 2015). For the peritidal facies of the Krka Member, microbially induced precipitation of the Ca–Mg carbonate precursor to dolomite is assumed, coupled with penecontemporaneous mi- metic dolomitization via evaporative pumping or seepage inf lux. In contrast, dolomitization via re- f lux of slightly evaporated seawater after deposi- tion of the sediment was suggested for the subtidal facies (Haas et al., 2015). In the case of the Hettangian-Sinemurian brec- cia, we thus assume that some of the clasts were dolomitized already prior to brecciation, and that pervasive dolomitization of the rest of the clasts, as well as the matrix of the breccia, took place via the ref lux of seawater after the deposition of the breccia and its subsequent burial by younger per- itidal deposits. The variations in dolomite textures between different clasts and matrix could be ex- plained by precursor grain size and mineralogical composition, and/or differences in concentrations of Mg ions in dolomitizing f luids (see Sibley & Gregg, 1987). The coarse-grained dolomite fabrics observed in some clasts, probably formed during later stages of diagenesis from finer-grained pre- cursors (Warren, 2000; Haas & Demény, 2002; Ogorelec, 2009). A similar early diagenetic dolomitization is as- sumed for the Toarcian breccia. However, due to deposition in a completely subtidal environment, it is possible that some other mechanism of do- lomitization should be applied, such as one of the normal marine dolomite models (see Warren, 2000, fig. 10). Conclusions Early Jurassic extensional tectonics is man- ifested in the northern sector of the Southern Tethyan Megaplatform of the central Slovenia in the presence of neptunian dykes and sills cutting through the peritidal dolostone, and in possible scarp breccias. The latter occur at two stratigraph- ic levels. The Hettangian – Sinemurian breccias are pervasively dolomitized. Clasts are poorly sorted and matrix supported. Their occurrence could be related to the “diffused rifting stage” rec- ognized across the western and central Southern Alps at the beginning of the Jurassic. The younger breccias some metres thick are Toarcian in age. They are matrix-supported with poorly sorted clasts. Limestone clasts predominate over dolo- mitic ones and are more variable in texture. Radi- al ooids, coral and sponge fragments occur within the matrix. Extensional tectonics had a significant effect on the architecture of the Southern Tethyan Meg- aplatform in the Early Jurassic. While the late Pliensbachian – Toarcian extension had a regional impact, leading to the breaking-up of the Southern Tethyan Megaplatform, the earlier extension may have governed the Hettangian – Pliensbachian transition from peritidal facies towards the pre- dominantly subtidal lagoon and shoal facies ob- served within the Podbukovje Formation. Acknowledgements The research was supported by the Slovenian Research Agency (research core fundings No. P1- 0011 and P1-0195). Thin sections were prepared at the Geological Survey of Slovenia. We thank the reviewers for their thorough reading of and con- structive remarks on the manuscript. 37Signs of crustal extension in Lower Jurassic carbonates from central Slovenia References Aubrecht, R. & Szulc, J. 2006: Deciphering of the complex depositional and diagenetic history of a scarp limestone breccia (Middle Jurassic Krasin Breccia, Pieniny Klippen Belt, Western Carpathians). Sed. 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CC Atribution 4.0 License Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov, ki odvodnjavajo odlagališča rudarskih odpadkov Contents of potentially toxic elements in sediments and waters of the Meža river and its tributaries draining mine waste deposits Mateja GOSAR, Špela BAVEC, Miloš MILER & Martin GABERŠEK Geološki zavod Slovenije, Dimičeva ulica 14, SI–1000 Ljubljana, Slovenija; e-mail: mateja.gosar@geo-zs.si Prejeto / Received 5. 12. 2023; Sprejeto / Accepted 20. 3. 2024; Objavljeno na spletu / Published online 29. 3. 2024 Ključne besede: rudarjenje, odlagališča rudarskih odpadkov, kovine in metaloidi, sedimenti, površinska voda, monitoring, rudnik Mežica Key words: mining, mine waste deposits, metals and metalloides, sediments, stream water, monitoring, Mežica mine Izvleček Predstavljeni so rezultati spremljanja vsebnosti potencialno strupenih elementov (PSE) v sedimentih (v letih 2013, 2017, 2020) in vodah (v letih 2017, 2020) reke Meže ter njenih pritokov, ki odvodnjavajo odlagališča rudarskih odpadkov. Skupno 13 vzorčnih mest je vzpostavljenih v vzorčni shemi, ki omogoča dolgoročno opazovanje vpliva odlagališč rudarskih odpadkov. V sedimentih so zaradi vplivov več kot 300-letnega delovanja rudarsko-predelovalne industrije močno povečane vsebnosti PSE, predvsem Pb, Zn, Cd, Mo in As, ki s časom precej nihajo. Razlike v vsebnostih na istih lokacijah v različnih letih so najbolj izrazite v pritokih reke Meže, ki drenirajo odlagališča rudarskih odpadkov. Na vsebnosti imajo pomemben vpliv hidrološki pogoji, saj so ob višjem vodostaju in višjem pretoku vsebnosti PSE večje. Vodna erozija odlagališč ima pomemben vpliv na dotok onesnaženega materiala v vodotoke. V nasprotju s pritoki, v zgornjem toku reke Meže nismo opazili večjega vpliva višjega vodostaja in pretoka na vsebnosti PSE v sedimentih. Dolvodno od Žerjava so nihanja vsebnosti med posameznimi leti oz. različnimi hidrološkimi pogoji tudi v Meži večja. Predstavljeni rezultati kažejo, da so v sedimentih reke Meže in njenih pritokov vsebnosti Pb, Zn, Cd, Mo in As zelo velike ter krepko presegajo zakonsko določeno kritično vrednost za tla. V površinski vodi so vsebnosti PSE lokalno povečane in se s časom bistveno ne spreminjajo. Glede na primerjavo z zakonodajnimi smernicami, so v obravnavanih vodah lokalno presežene koncentracije Pb, Cd in Zn. Ocenjujemo, da je dinamika obremenjenosti sedimentov reke Meže s PSE vzdolž krajev Črna na Koroškem, Žerjav in Mežica zelo kompleksna. Poleg odlagališč rudarskih odpadkov na vsebnosti PSE v sedimentih in vodah vplivajo tudi razpršeni viri v okolju, kot so onesnažena tla in poplavne ravnice ter njihova različna stopnja onesnaženosti, saj je okolje obremenjeno zaradi dolgoletnih rudarskih in talilniških dejavnosti. Dodaten okoljski vpliv ima morda tudi sedanja industrijska dejavnost v dolini reke Meže. Abstract The results of the monitoring of the contents of potentially toxic elements (PTE) in sediments (2013, 2017, 2020) and waters (2017, 2020) of the Meža River and its tributaries, which drain mining waste deposits, are presented. A total of 13 sample sites were established in a sample scheme that enables long-term observation of the impact of mining waste deposits. In the sediments, the content of PTE, especially Pb, Zn, Cd, Mo and As, is greatly elevated and f luctuates with time. The study area is affected by more than 300 years of mining and ore processing industry. The differences in the contents in various years are most pronounced in the Meža River tributaries, which drain the mining waste dumps. Hydrological conditions have a significant inf luence on the contents in sediments, as PTE content increases with higher water level and higher water f low. Water erosion of mining waste dumps has a significant impact on the discharge of contaminated material into watercourses. In contrast, in the upper part of the Meža River, we did not observe strong inf luence of higher water level on the content of PTE in the sediments. Fluctuations in the content between individual years and f luctuations between various hydrological conditions are higher again in the middle part of the the Meža river, downstream from Žerjav. The presented results demonstrate that the contents of Pb, Zn, Cd, Mo and As in the sediments of the Meža River and its tributaries are very high and that they by far exceed the legislative critical value for the soil. PTE contents in the surface water are elevated in some locations and do not change significantly over time. The local concentrations of Pb, Cd and Zn exceed the legislative guidelines. We estimate that the dynamics of the sediment load in the Meža River along the towns of Črna na Koroškem, Žerjav and Mežica is very complex. In addition to mining waste deposits, the content of PTE in sediments and waters is also affected by scattered sources in the environment, such as contaminated soil and f loodplains and their varying degrees of pollution, as the environment has been burdened by long-term mining, ore processing and smelting activities. Current industrial activity may also have an additional environmental impact. GEOLOGIJA 67/1, 41-61, Ljubljana 2024 https://doi.org/10.5474/geologija.2024.003 42 Mateja GOSAR, Špela BAVEC, Miloš MILER & Martin GABERŠEK Uvod Dolgoletno rudarjenje, različna industrija, pro- met in druge človekove dejavnosti lahko povzročijo povečanje vsebnosti nekaterih elementov v okolju (npr. v tleh, sedimentih) ter spremembe naravnega kroženja elementov. Človekove dejavnosti so geo- loško recentne in lahko izrazito vplivajo na naše okolje in so globalno prevladujoči vzrok za večino sodobnih okoljskih sprememb (Lewis & Maslin, 2015). Geokemično kartiranje tal v kontinental- nem merilu (projekt GEMAS) je pokazalo, da so prisotnost rudišč s spremljajočo rudarsko-prede- lovalno industrijo, litološka sestava in podnebje pomembni dejavniki, ki vplivajo na porazdelitve elementov v tleh. Na primer, pozitivne anomalije svinca zaznamujejo večino mineraliziranih ob- močjih po Evropi (Reimann et al., 2012), delo- vanje največjega rudnika živega srebra (Almadén) pa je povzročilo veliko pozitivno anomalijo žive- ga srebra v osrednji Španiji (Ottesen in sodelavci, 2013; Ballabio et al., 2021). Tudi v Sloveniji so bili ugotovljeni lokalni in regionalni vplivi dolgolet- nega pridobivanja kovinskih mineralnih surovin (Šajn & Gosar, 2004; Gosar et al., 2006; Fux & Gosar, 2007; Gosar & Miler, 2011; Miler & Gosar, 2012; Žibret et al., 2018; Gosar et al., 2019; Miler et al., 2022). Kovine in drugi potencialno strupeni elementi (PSE), prvotno sproščeni v okolje zara- di rudarjenja in predelave rud, so po nekaj letih razpršeno prisotne v različnih predelih površja kot difuzna onesnaževala v tleh in sedimentih ter nakopičene v različnih odlagališčih, od katerih so najpomembnejša odlagališča rudarskih odpadkov (Salomons & Förstner, 1988; Kesler, 1994; Boni et al., 1999). Po hujših okoljskih nesrečah povezanih tudi z odloženimi rudarskimi odpadki v svetu v zadnjih 30-tih letih (na primer Aznacolar leta 1998 (Galán et al., 2002) in Baia Mare leta 2000 (Cunningham, 2005), se je pokazala potreba po ustreznejši za- konodaji. Evropska komisija je leta 2006 sprejela Uredbo o ravnanju z odpadki iz rudarskih in drugih ekstraktivnih dejavnosti (v nadaljevanju Direktiva 2006/21/ES), s katero je določila ukrepe, postop- ke in smernice za preprečevanje ali zmanjševanje škodljivih vplivov na okolje, zlasti na vodo, zrak, tla, favno in f loro, pokrajine, ter tveganj za zdravje ljudi, ki so nastali kot posledica ravnanja z odpad- ki iz ekstraktivnih dejavnosti. Ti ukrepi zajemajo ravnanje z odpadki, ki nastanejo pri raziskovanju, pridobivanju, bogatenju in skladiščenju mineralnih surovin. Direktiva 2006/21/ES je bila leta 2008 prenesena tudi v pravni red Slovenije (Uradni list RS, št. 43/08, 30/11, 64/21 in 44/22 – ZVO-2). V omenjeni direktivi je med drugim navedeno, da mora vsaka država članica zbrati podatke o zaprtih in opuščenih odlagališčih rudarskih odpadkov ter opredeliti ali obstaja potencialna nevarnost, da bi ta odlagališča lahko povzročila resne škodljive vplive na okolje in srednjeročno ali kratkoročno postala resna grožnja za zdravje ljudi ali okolje. Geološki zavod Slovenije (GeoZS) je zbiral potreb- ne podatke o zaprtih in opuščenih odlagališčih ru- darskih odpadkov ter po posebni metodologiji, ki smo jo podrobno opisali Gosar in sodelavci (2014; 2017; 2020; 2021), določil tista zaprta odlagališča rudarskih odpadkov, ki bi lahko povzročila resne škodljive vplive na okolje in bi zato lahko obstajala resna grožnja za zdravje ljudi ali okolje ter jih je zato potrebno, skladno z omenjeno direktivo, red- no (na vsaka 3 leta) opazovati oz. spremljati. Zaradi več kot 300 let trajajoče rudarsko-pre- delovalne dejavnosti je območje zgornje Mežiške doline močno obremenjeno. Analize tal (Kugonič & Zupan, 1999; Vreča et al., 2001; Šajn, 2006; Zupan et al., 2008; Finžgar et al., 2014) so poka- zale močno onesnaženost s Pb, Zn in Cd. Z geoke- mičnim kartiranjem tal sta Šajn in Gosar (2004) ugotovila, da so tla najbolj onesnažena v okolici Žerjava in Črne. Območje kritično onesnaženih tal se nadaljuje s prekinitvami vzdolž reke Meže vse do Raven na Koroškem. Prva sistematična analiza sedimentov vodotokov (reka Meža in njeni pritoki) je pokazala, da so med PSE vsebnosti Pb, Zn in Cd večinoma velike ali povečane (Bole et al., 2002). Kasnejše sistematične analize (Fux & Gosar, 2007; Gosar & Miler, 2011) so pokazale močno onesna- ženost sedimentov zgornjega toka reke Meže s Pb, Zn, Mo, Cd in deloma z As, v nižjih delih pa so bile vsebnosti teh elementov manj velike, še vedno pa so močno presegale vrednosti naravnega ozadja. Poleg tega so bile vsebnosti Co, Cr, Cu in Ni pove- čane na območju Raven zaradi železarske industri- je. Skupna ugotovitev študij sedimentov (Svete et al., 2001; Bole et al., 2002; Fux & Gosar, 2007; Go- sar & Miler, 2011; Miler & Gosar, 2012) je bila, da so izjemno velike vsebnosti PSE (še posebno Pb, Zn in Cd) v sedimentih Helenskega potoka posle- dica odvodnjavanja odlagališč rudarskih odpad- kov (Helena in Štoparjev odval). Bole in sodelav- ci (2002) so ugotovili, da so v Helenskem potoku vsebnosti Pb, Cd in Zn povečane tudi v površinski vodi. Miler in Gosar (2012) sta primerjala in ugo- tovila dobro ujemanje med mineralnimi oblikami ter količinami rudnih mineralov, ki vsebujejo PSE v sedimentu iz Helenskega potoka ter materialu iz gorvodnega odlagališča rudarskih odpadkov (Štoparjev odval). Podobno so Gošar in sodelavci (2015) opazili, da so, zaradi prisotnosti rudarskih odpadkov v zaledju, koncentracije Cr, Cu, Pb in Zn 43Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov ... v vodi v Helenskem potoku nekoliko povečane. V reki Meži dolvodno od Mežice pa so opazili izrazito večje koncentracije Pb in Zn ter v manjši meri tudi Cd, kar so pripisali vplivu rudarskih odpadkov v zaledju in najverjetneje tudi prisotnosti tovarne baterij in druge metalurške industrije na tem ob- močju (Gošar et al., 2015). Novejše raziskave po- razdelitve vsebnosti v sedimentih in površinski vodi v reki Meži in pritokih (Goltnik et al., 2022; Miler et al., 2022) so potrdile, da so vsebnosti Pb, Zn in Cd ter v manjši meri Mo in As v sedimentih še vedno zelo velike, medtem ko so v površinski vodi povečane v pritokih Meže, predvsem tistih, ki dre- nirajo odlagališča rudarskih odpadkov, v Meži pa predvsem na lokacijah dolvodno od Žerjava, kjer se nahaja trenutno dejavna industrija. Miler in sode- lavci (2022) so z razmerji Pb izotopov ugotovili, da obstajajo različni viri Pb v sedimentih. Pomemben vir so primarni Pb rudni minerali, ki se nahajajo v orudenih kamninah. Drugi viri so produkti pre- perevanja, vplivi sedanje industrije v Žerjavu (re- ciklaža Pb odpadkov) in različna litologija. Poleg tega so izmerili ekstremno velike vsebnosti Pb, Zn in Cd na odlagališčih rudarskih odpadkov, močno sta povečana tudi As in Mo. Z uporabo geoaku- mulacijskega indeksa so ugotovili, da so sedimenti dolvodno od odlagališč rudarskih odpadkov veči- noma močno do zelo močno obremenjeni s PSE. Goltnik in sodelavci (2022) so ocenili, da zaradi velikih vsebnosti PSE, obstaja visoko tveganje za vpliv PSE na vodne organizme, da so vsebnosti Pb, Zn in Cd večje v frakciji < 0,063 mm v primerjavi s frakcijo < 0,150 mm, ter da se razmerja Pb izo- topov prostorsko razlikujejo, kar pomeni, da so na območju prisotni različni viri Pb. Med viri onesnaženja na preiskovanem obmo- čju so v preteklosti prevladovali rudarjenje in pre- delava rude (talilnica svinca). V novejšem času pa poleg močno obremenjenega okolja, še reciklaža svinčevih odpadkov in ostali zelo raznoliki viri (promet, druga industrija, urbanizacija, kmetij- stvo). Tako so danes med najpomembnejšimi viri odlagališča rudarskih odpadkov (Budkovič et al., 2003; Miler & Gosar, 2012; Miler et al., 2022), nekdanji rudarski revirji z metalurško dejavno- stjo, onesnažene poplavne ravnice (Bidovec, 1997) in onesnažena tla (Šajn & Gosar, 2004). Dodatno k onesnaženju prispeva tudi današnja sekundarna predelava Pb odpadkov (Svete et al., 2001; Miler & Gosar, 2013, 2019; Žibret et al., 2018; Miler et al., 2022). Pomemben pretekli vir obremenitve vodo- tokov je bilo sproščanje mulja iz separacijske jalo- vine v reko Mežo do leta 1980 (Žibret et al., 2018). Po letu 1980 so začeli mulj odlagati v opuščene dele rudnika, v stare odkope in tako razbremenili reko Mežo (Fajmut Štrucl & Pungartnik v Eržen et al., 2002). Poleg imisij v tleh, prahu, zraku in drugih okoljskih medijih so sedaj pomembni viri Pb in ne- katerih drugih PSE odlagališča rudarskih odpad- kov in dejavnosti, povezane z industrijo. V kamno- lomu Žerjav rudarski odpadni material, ki vsebuje veliko svinca in drugih PSE (Miler & Gosar, 2012), reciklirajo v prodajne izdelke za uporabo v grad- beništvu. Gradbeni material se pogosto uporablja v lokalnem okolju. V Žerjavu se izvajajo dejavnost recikliranja odpadkov za pridobivanje Pb, končni odpadki iz procesa recikliranja pa se odlagajo na bližnje odlagališče nevarnih odpadkov (NOMO). Upravljanje odlagališča je pod nadzorom Ministr- stva za okolje, podnebje in energijo. V Črni na Ko- roškem obratuje proizvodnja startnih baterij. Oba industrijska objekta sta uvrščena med industrijske dejavnosti, ki lahko povzročijo onesnaževanje oko- lja v večjem obsegu, zato sta zavezana k stalnemu monitoringu. Na sliki 1 so prikazana večja odla- gališča rudarskih odpadkov, industrijski objekti in odlagališči za nevarne in nenevarne odpadke. Namen pričujočega članka je strokovni in splo- šni javnosti predstaviti izsledke raziskav vpliva zaprtih odlagališč rudarskih odpadkov na sedi- mente in površinske vode na območju nekdanjega rudnika v Mežici od leta 2013 do leta 2020. Poseb- no pozornost smo posvetili vsebnostim PSE v se- dimentih in površinskih vodah dolvodno od ome- njenih odlagališč ter njihovi časovni variabilnosti in vplivu hidroloških pogojev na vsebnosti PSE v sedimentih. Metode Preiskovano območje, vzorčenje, priprava in analiza vzorcev Preiskovano območje zajema del vodotoka reke Meže s pritoki (celotno porečje Meže meri 551,68 km2; Kolbezen & Pristov, 1998), kjer se v hidrološkem zaledju nahajajo odlagališča rudar- skih odpadkov. To je od območja po pritoku potoka Topla do Prevalj (sl. 1). Na preiskovanem območju se nahaja zaprti rudnik Mežica, kjer so 300 let pridobivali rudo, iz katere so pridobivali svinec, cink in v zadnjih desetletjih delovanja tudi molibden. Rudišče je epigenetsko tipa Mississippi Valley (MVT), kjer poteka mineralizacija v srednje- do zgornjetrias- nih dolomitih in apnencih (Drovenik et al., 1980; Štrucl, 1984; Zeeh et al., 1998; Spangenberg et al., 2001). Glavna rudna minerala sta bila galenit in sfalerit (Drovenik et al., 1980; Štrucl, 1984). Spek- tralne analize rudnih mineralov iz Mežice kažejo, de je slednih prvin v sfaleritu malo. Edina prvina, 44 Mateja GOSAR, Špela BAVEC, Miloš MILER & Martin GABERŠEK Sl. 1. Shematski prikaz obravnavanega območja z označenimi opazovanimi rudarskimi odlagališči in vzorčnimi mesti za sedimente in vode. Fig. 1. Schematic study area map with marked observed mining waste deposits and sampling sites for sediments and water. je najbolj razširjen v zgornjem delu rudišča, nje- gova količina pa z globino upada (Drovenik et al., 1980). Pridobivanje Pb-Zn rude in primarno talje- nje Pb na območju Mežice sta prenehala leta 1995, talilnica pa se je preoblikovala v obrat za reciklažo Pb-odpadkov in izrabljenih Pb-kislinskih baterij (sekundarna predelava Pb). ki jo vsebujejo vsi vzorci v večji količini je Cd. V skorjastem sfaleritu je sorazmerno veliko As in Tl. Galenit vsebuje le malo slednih prvin, izjema je As, ki ga je v nekaterih vzorcih veliko, v drugih pa manj. Za mežiški galenit sta značilni izredno majhna vsebnost Ag in rahla obogatitev s Sb. Mo- libden v mežiškem rudišču je vezan v wulfenit, ki 45Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov ... Na območju Mežice je 32 deponij rudar- skih odpadkov s skupno prostornino približno 7.400.000 m3 (Gosar et al., 2020), kjer so odpadni materiali odlagali na odlagališča v bližnjih ozkih dolinah in na strmih pobočjih manjših potokov. Večinoma so odlagališča sestavljena iz karbonat- nih kamnin v katerih se nahaja rudišče (Gosar & Miler, 2011; Miler & Gosar, 2012; Miler et al., 2022 in tam navedeni viri), a tudi iz revne rude in sepa- racijske jalovine ali žlindre. Pritoki Meže, ki smo jih obravnavali, so Helenski potok, Mušenik, Jazbinski potok, Junčarjev potok z dvema pritokoma, ki nimata jasnega geografske- ga imena, zato smo jih poimenovali kot pritok 1 (ang. tributary 1) in pritok 2 (ang. tributary 2; po nekaterih virih imenovan tudi Kavšakov potok). Odlagališča odpadkov, ki jih potoki drenirajo, so podana v tabeli 1 in prikazana na sliki 1. Helenski potok in Jazbinski potok spadata med večje prito- ke, medtem ko so ostali pritoki manjši. Reka Meža ima pretežno hudourniški značaj, medtem ko ima- jo njeni pritoki izrazit hudourniški značaj in s tem tudi veliko erozijsko moč (Kuzmič & Suhadolnik, 2005), ki je bila v primeru izjemno obilnih pada- vin tekom vremenske ujme v začetku avgusta 2023 tudi rušilna. Struge Meže in pritokov so v naseljih delno regulirane, izven naselij pa so zaradi velikih vzdolžnih padcev dna ter hudourniškega značaja pogosto izpostavljene eroziji (Kuzmič & Suhadol- nik, 2005). Vzorčenje potočnih in rečnih sedimentov je bilo izvedeno leta 2013 (25. 11. in 28. 11.), leta 2017 (8. 6.) in leta 2020 (29. 10. in 30. 10.), vsakič na skup- no 13 vzorčnih mestih v Meži in njenih pritokih, ki so podana v tabeli 1 in prikazana na sliki 1. V letih 2017 in 2020 je bil sočasno z vzorčenjem sedimen- tov na istih mestih odvzet tudi vzorec vode. Vodostaj in pretok reke Meže v času vzorčenj povzemamo po podatkih arhiva površinskih voda Agencije Republike Slovenije za okolje, in sicer za postaji Črna (Č) in Otiški vrh I (OV). Pri vodo- merni postaji Otiški vrh I je potrebno upoštevati, da se pred njo v Mežo izliva večji pritok Mislinja. Na prvi dan vzorčenja sta bila pretok in vodostaj največja leta 2013 (Č: 86 cm in 7,6 m3/s ter OV: 190 cm in 60,3 m3/s) in najmanjša leta 2017 (Č: 42 cm in 1,1 m3/s ter OV: 108 cm in 7,8 m3/s) (sl. 2a, b). Leta 2020 sta bila vodostaj in pretok nekoli- ko večja kot leta 2017 (Č: 66 cm in 3,3 m3/s ter OV: 116 cm in 14,5 m3/s). Poleg tega sta bila vodostaj in pretok leta 2020 dlje časa (skupno 3 tedne) pred vzorčenjem konstantna, medtem ko sta v letu 2013 in 2017 nihala (eden ali več intenzivnejših pada- vinskih dogodkov). Padavinski dogodki leta 2013 Tabela 1. Podatki o vzorčnih lokacijah. Table 1. Sampling locations data. Oznaka lokacije / Mark of sampling site Zemljepisna dolžina / Longitude Zemljepisna širi- na / Latitude Vodotok / Watercourse Odlagališče rudarskih odpadkov / Mine waste spoil heaps SS-26/3 14,8083 46,4682 Meža - SS-26/5 14,8216 46,4709 Helenski potok K-26/1 (Drče), K-26/11 (Pavel Mulb), K-26/12 (Štoparjev odval), K-26/13 (Helena) SS-26/6 14,8349 46,4674 Meža - SS-26/7 14,8503 46,4793 Mušenik K-26/17 (Igrče) SS-26/8 14,8552 46,4814 Pritok 1/Tributary 11 K-26/18 (Unionski odval), K-26/19 (Matjaževo odlagališče), K-26/20 (Svitni), K-26/21 (Frančišek) SS-26/9 14,8664 46,4817 Meža - SS-26/10 14,8728 46,4854 Jazbinski potok K-26/22 (Kavšakovo odl.), K-26/23 (Žerjavski odval) SS-26/11 14,8778 46,4835 Pritok 2/Tributary 21 K-26/22 (Kavšakovo odl.) SS-26/15 14,8677 46,5022 Meža - SS-26/19 14,8635 46,5091 Junčarjev potok K-26/27 (Srce), K-26/28 (Lekšeče), K-26/30 (Fridrih) SS-26/20 14,8626 46,5132 Meža - SS-26/21 14,8554 46,5257 Meža K-26/31 Glančnik SS-26/22 14,9031 46,5431 Meža - 1manjši vodotoki, ki nimajo uradnega geografskega poimenovanja / smaller watercourses that do not have an official geographical name 46 Mateja GOSAR, Špela BAVEC, Miloš MILER & Martin GABERŠEK so bili bolj intenzivni kot leta 2017. Nihanja vodo- staja in pretoka sta v opazovanih obdobjih 2023 in 2017 podobna na obeh vodomernih postajah (sl. 2a,b). Drobnozrnati sediment je bil na vsakem vzorčnem mestu odvzet na najmanj petih loka- cijah v medsebojni razdalji 5 do 10 metrov. Tako pridobljen združeni vzorec je tehtal od 1 do 2 ki- lograma. Zračno posušene vzorce sedimentov smo presejali s sitom iz nerjavečega jekla na frakcijo < 0,125 mm, v kateri smo analizirali vsebnosti PSE. Kemična analiza vzorcev sedimentov je bila opravljena v laboratoriju Bureau Veritas Mineral Laboratories (mednarodna akreditacija ISO/IEC -20 -19 -18 -17 -16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 pretok / flow 2013 4,0 3,2 2,2 1,6 9,6 12,1 9,7 6,1 5,2 4,5 4,0 3,5 3,0 2,7 3,1 4,5 3,6 3,5 10,4 12,9 7,6 pretok / flow 2017 0,9 0,9 0,9 0,9 0,9 0,9 0,9 0,9 0,8 0,8 0,8 0,8 0,8 0,9 0,9 0,9 0,8 0,8 0,8 1,1 1,1 pretok / flow 2020 3,8 3,3 6,6 7,9 7,2 6,2 7,7 8,7 7,3 6,2 5,4 4,8 4,3 4,0 3,7 3,3 3,1 2,7 5,6 4,0 3,3 vodostaj / water level 2013 72 69 63 59 85 99 92 81 78 75 73 71 68 67 68 75 71 71 91 100 86 vodostaj / water level 2017 40 39 39 39 39 38 38 38 37 37 37 37 38 39 40 38 37 37 38 43 42 vodostaj / water level 2020 69 67 79 84 82 78 83 86 82 78 75 73 71 70 68 67 65 63 75 70 66 0 20 40 60 80 100 120 0 2 4 6 8 10 12 14 vo do st aj (w at er le ve l) -Č rn a (M ež a) (c m ) pr et ok (fl ow )- Čr na (M ež a) (m 3 / s) dan / day (a) -20 -19 -18 -17 -16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 pretok / flow 2013 29,4 23,7 16,2 13,2 59,2 71,9 58,2 40,3 33,3 28,9 25,9 23,3 20,4 18,2 18,2 23,1 20,6 24,1 51,2 91,0 60,3 pretok / flow 2017 5,6 5,4 5,4 5,4 5,6 5,1 5,1 4,8 4,7 4,6 4,5 4,4 4,6 6,1 7,8 7,2 5,3 4,9 5,3 8,7 7,8 pretok / flow 2020 17,0 15,5 36,8 46,3 33,3 26,7 31,9 34,0 28,1 24,2 21,5 19,6 18,2 17,0 16,0 15,5 14,9 13,8 19,2 16,3 14,5 vodostaj / water level 2013 142 133 121 115 178 205 187 160 149 142 137 133 128 124 124 132 128 134 174 229 190 vodostaj / water level 2017 101 100 100 100 101 99 99 98 97 97 96 96 97 103 107 106 100 98 100 111 108 vodostaj / water level 2020 121 118 152 169 149 138 147 151 141 134 129 126 123 121 119 118 116 114 124 119 116 0 50 100 150 200 250 0 10 20 30 40 50 60 70 80 90 100 vo do st aj (w at er le ve l) -O tiš ki v rh I (M ež a) (c m ) pr et ok (fl ow )- O tiš ki v rh I ( M ež a) (m 3 / s) dan / day (b) Sl. 2. Vodostaj (cm) in pretok (m3/s) na vodomernih postajah Črna (a) in (b) Otiški vrh I (po pritoku Mislinje) na reki Meži v 20. dneh pred začetkom in prvi dan vzorčenja v letu 2013, 2017 in 2020 (Vir podatkov: Arhiv površinskih voda, Agencija Republike Slovenije za Okolje). Fig. 2. Water level (cm) and flow (m3/s) at the water measuring stations of Meža river (a) Črna and (b) Otiški vrh I (after Mislinja confluent) 20 days before the start and on the 1st day of sampling in 2013, 2017 and 2020 (Source of data: Archive of surface waters, Slovenian Envi- ronment Agency). 47Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov ... 17025:2017), v Vancouvru v Kanadi. Za določitev vsebnosti 11 elementov (As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Zn) je bilo 15 g vzorca (izjemoma 0,5 g, v primeru da vzorca ni bilo dovolj) prelitega z modificirano zlatotopko (mešanica kislin HCl in HNO3 ter vode v razmerju 1:1:1), eno uro segreva- no na 95 °C in potem primerno razredčeno z desti- lirano vodo. Vsebnosti elementov v raztopini (ki- slinskem izvlečku) so bile določene z induktivno sklopljeno plazemsko (ICP) masno spektrometrijo (MS) ali optično emisijsko spektrometrijo (OES). Na podlagi ponovitev štirih vzorcev in analize standardov OREAS 45d ter 45e je bila kakovost analitike ocenjena kot ustrezna. Vzorci vode so bili na terenu prefiltrirani pre- ko filtra < 0,45 µm in shranjeni v 60 ml HDPE plastenke, ki so bile predhodno dvakrat sprane z vzorčeno vodo. Ob vzorčenju vode smo izmerili pH, temperaturo vode (T), oksidacijsko-redukcij- ski potencial (Eh), električno prevodnost (EC) in količino raztopljenega kisika (DO). Odvzeti vzorci vode so bili shranjeni na hladno (8–10 °C). Kemič- ne analize vode so bile opravljene v laboratoriju Activation Laboratories Ltd. (Actlabs; mednaro- dna akreditacija ISO/IEC 17025:2017) v Kanadi. V laboratoriju so bili vzorci najprej za nekaj dni zakisani z ultra čisto dušikovo kislino na pH < 2, da so se morebitno oborjene snovi ponovno razto- pile. Nato so bili analizirani z induktivno skloplje- no plazemsko (ICP) masno spektrometrijo (MS) in optično emisijsko spektrometrijo (OES). Kakovost analitike je bila zagotovljena s ponovitvami šestih vzorcev in uporabo standarda IV-STOCK-1643 (ICP/MS). Rezultati in razprava Vsebnosti potencialno strupenih elementov v sedimentih Vsebnosti 11 PSE (As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Zn) v obravnavanih vzorcih sedimen- tov so podane v tabeli 2. Ker slovenska okoljska zakonodaja trenutno ne predpisuje standardov kakovosti za potočne oz. rečne sedimente, smo vsebnosti PSE primerjali z normativnimi (mejni- mi in kritičnimi) vrednostmi za tla (tabela 2), ki so predpisane v Uredbi o mejnih, opozorilnih in kritičnih imisijskih vrednostih nevarnih snovi v tleh (Uradni list RS, št. 68/96, 41/04 – ZVO-1 in 44/22 – ZVO-2). Mejne in kritične vrednosti za tla po slovenski uredbi so zelo blizu vrednostim po t.i. nizozemski listi »The New Duch list« (VROM, 2000), ki je veljala tako za tla kot sedimente. Za Ba smo vzeli mejno vrednost po nizozemski listi (VROM, 2000), ker v slovenski zakonodaji ni de- finirana. Posebej smo izpostavili vsebnosti, ki presegajo 2 × kritično vrednost, da bi izpostavili s PSE zelo obremenjena območja (tabela 2). V pritokih Meže so vsebnosti Pb (tabela 1, sl. 3) v sedimentih v vseh opazovanih letih presegale kritično vrednost v Helenskem potoku (SS-26/5), v pritoku 1 (SS-26/8), v pritoku 2 (SS-26/11) in v Junčarjevem potoku (SS-26/19). Nekoliko man- jše vsebnosti, a še vedno večinoma nad kritično vrednostjo, smo izmerili v Jazbinskem potoku (SS-26/10) ter v Mušeniku (SS-26/7). Ugotavlja- mo, da so bile vsebnosti Pb v sedimentih iz prito- kov Meže, ki neposredno drenirajo odlagališča (z izjemo Jazbinskega potoka in pritoka 2), največje v letu 2013, ko sta bila pretok in vodostaj najvišja. Slednje verjetno odraža močan vpliv vodne erozi- je odlagališč na povečanje vsebnosti v sedimentih pritokov Meže. Slednje ne velja za Jazbinski potok in pritok 2. Zelo verjetno je vzrok temu dobra za- jezitev materiala pod Kavšakovo haldo, katere od- točne vode napajajo pritok 2, ki se izliva v Jazbin- ski potok in slednji v Mežo. Kavšakovo haldo vrsto let uporabljajo kot vir nekovinskih mineralnih su- rovin, predvsem za gradbene namene. Jazbinski potok pred pritokom 2 v zaledju drenira le nekaj majhnih odlagališč rudarskih odpadkov (Gosar et al., 2021). Sklepamo, da sta majhen vpliv odlaga- lišč rudarskih odpadkov v zaledju Jazbinskega po- toka pred izlivom pritoka 2 ter dobra zajezitev iz- toka materiala iz Kavšakovega odlagališča glavna vzroka za podobne vsebnosti Pb v času različnih vodostajev in pretokov. Na večini vzorčnih mest v Meži so bile vsebno- sti Pb velike. Kritična vrednost za Pb je bila pre- sežena v vseh opazovanih letih na vseh lokacijah, z izjemo lokacije SS-26/9 v letu 2020, kjer je bila vsebnost Pb med mejno in kritično vrednostjo ter lokacije SS-26/3, ki je v zgornjem toku Meže. Na slednji so bile vsebnosti glede na ostale lokaci- je zelo majhne, kar je pričakovano, saj se nahaja gorvodno od večine v uvodu predstavljenih virov Pb. V nasprotju z večino pritokov, vsebnosti Pb v sedimentih Meže niso bile znatno večje v obdobju povišanega vodostaja in pretoka, razen na lokaci- jah SS-26/21 in SS-26/22 (večkratno povišanje v 2013 v primerjavi z letoma 2017 in 2020), ki sta iz- med 13 vzorčnih mest najbolj oddaljeni (dolvodno) od virov Pb v Zgornji Mežiški dolini. Možen raz- log za izrazito večje vsebnosti v letu 2013 bi lahko bila povečana erozija s Pb močno obremenjenih poplavnih ravnic. Poleg tega je potrebno upošteva- ti, da se lokacija SS-26/22 nahaja tik za rovom, ki drenira rudnik, in da so bile na tej lokaciji vedno ugotovljene velike vsebnosti Pb ter prisotnost ve- like količine Pb-oksidnih/karbonatnih mineralov 48 Mateja GOSAR, Špela BAVEC, Miloš MILER & Martin GABERŠEK Tabela 2. Vsebnosti As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb in Zn (v mg/kg). Table 2. Contents of As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb and Zn (in mg/kg). Vzorčno mesto / Sampling site Leto / Year Vodotok / Watercourse As Ba Cd Co Cr Cu Hg Mo Ni Pb Zn SS-26/3 20131 Meža 6,4 28 1,4 7,0 18,3 11,4 0,04 1,7 16,7 93 288 20171 8,8 30 2,2 8,2 16,2 14,8 0,09 1,8 19,2 83 358 2020 6,5 28 1,9 6,1 17,5 9,6 0,11 2,1 14,5 135 336 SS-26/5 20131 Helenski potok 33,7 53 102,9 4,3 17,6 28,4 0,15 149 15,1 9149 18200 20171 23,8 60 64,9 7,5 15,9 37,4 0,13 97,7 22,4 4982 8169 2020 14,3 47 24,7 7,4 13,8 21,3 0,08 21,1 19,7 1828 3507 SS-26/6 20131 Meža 7,7 33 5,6 6,6 21,5 12,4 0,16 14,1 14,9 887 805 20171 11,2 40 11,4 8,9 17,6 16,2 0,10 18,3 19,8 929 1561 2020 8,1 34 8,2 5,9 18,1 12,1 0,09 26,2 14,0 1130 1216 SS-26/7 20131 Mušenik 6,7 28 5,4 2,1 7,4 8,5 0,02 15,8 6,6 815 656 20171 4,5 12 2,6 1,4 3,2 4,2 0,04 8,9 3,0 337 364 2020 3,4 9 1,5 1,3 3,9 2,8 0,02 4,9 2,3 178 180 SS-26/8 20131 pritok 1 /tributary 1 71,8 205 81,1 2,3 14,4 13,3 0,34 3310 9,1 46200 14500 20171 25,3 108 40,2 3,3 10,4 12,0 0,26 286 8,8 5213 5107 2020 40,2 165 57,2 4,2 16,2 13,8 0,37 749 11,4 13533 7684 SS-26/9 20131 Meža 13,1 150 7,2 11,5 30,6 24,7 0,85 33,3 21,9 1672 1235 20171 13,5 128 9,5 12,0 23,9 27,7 0,31 18,3 21,8 1430 1341 2020 8,4 85 5,1 14,2 32,9 24,6 0,20 10,2 31,8 498 814 SS-26/10 20131 Jazbinski potok 6,0 95 1,7 4,0 10,3 13,2 0,29 5,2 10,7 634 282 20171 10,2 44 6,0 3,0 8,3 18,7 0,13 6,6 9,3 671 529 2020 6,8 61 2,0 4,9 10,1 12,2 1,15 4,9 11,8 419 306 SS-26/11 20131 pritok 2 / tributary 2 23,7 307 103,9 1,1 7,2 10,5 0,10 17,7 6,7 3289 16600 20171 29,1 308 116,3 1,9 7,1 14,0 0,13 21,5 7,0 2470 17600 2020 37,0 196 94,8 5,4 19,1 73,6 0,38 38,2 33,1 4079 13800 SS-26/15 20131 Meža 27,6 124 14,7 9,1 28,3 42,9 0,19 104 21,8 7593 2665 20171 27,4 89 18,6 7,4 27,7 85,0 0,75 92,1 32,1 7611 2208 2020 10,8 77 5,8 10,7 26,0 23,8 0,12 11,3 26,3 1171 844 SS-26/19 20131 Junčarjev potok 20,6 285 25,5 1,2 6,2 8,8 0,04 122 5,2 4187 5834 20171 23,1 271 20,3 3,0 9,1 16,1 0,11 50,6 7,9 1733 3854 2020 13,0 212 12,8 1,1 4,9 4,9 0,04 32,1 3,7 1035 2530 SS-26/20 20131 Meža 17,1 119 8,0 9,3 25,2 30,8 0,79 70,2 21,9 4527 1337 20171 34,3 110 22,7 9,6 33,8 57,3 0,56 160 29,0 9198 3027 2020 11,5 84 7,2 10,5 26,6 24,5 0,19 17,1 25,8 1481 1144 SS-26/21 20131 Meža 24,6 132 23,0 8,7 26,9 35,0 0,13 113 19,5 7751 3728 20171 8,9 87 10,0 8,8 24,0 47,1 0,24 6,5 23,2 825 1090 2020 11,9 77 9,6 10,1 26,7 24,4 0,15 29,2 26,0 2019 1460 SS-26/22 20131 Meža 37,9 128 30,1 10,3 44,0 54,3 0,79 361 25,3 23100 5083 20171 22,1 136 17,0 13,2 33,5 45,9 0,22 70,7 32,4 3383 2302 2020 13,9 74 7,7 12,1 29,8 24,3 0,10 38,3 29,4 1737 1269 mejna vrednost / border (mg/kg)2 20 1603 1 20 100 60 0,8 10 50 85 200 kritična vrednost (mg/kg)2 55 6253 12 240 380 300 10 200 210 530 720 1Podatki povzeti po Miler et al. (2022) / Data after Miler et al. (2022) 2Mejne in kritične vrednosti povzete iz Uredbe o mejnih, opozorilnih in kritičnih imisijskih vrednostih nevarnih snovi v tleh (Ur. l. RS, št. 68/96, 41/04 – ZVO-1 in 44/22 – ZVO-2) / (Limit and critical values summarized from the Decree on limit values, alert thresholds and critical levels of dangerous substances into the soil (Ur. l. RS, št. 68/96, 41/04 – ZVO-1 in 44/22 – ZVO-2) 3Vrednosti povzete iz »The New Duch list« (VROM, 2000) / Values summarized from »The New Dutch list« (VROM, 2000) S črno barvo so zapisane vsebnosti pod mejno, z modro med mejno in kritično vrednostjo, z rdečo ne-odebeljeno vsebnosti nad kritično in pod 2 × kritično vrednostjo ter odebeljeno rdeče vsebnosti nad 2 × kritično vrednostjo / Contents below limit values are colored black, between limit and critical value in blue, above the critical value and below the 2 × critical value in red and above the 2 × critical value in bold red 49Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov ... v sedimentih (Miler et al., 2022). Na preostalih lokacijah v Meži, ki se nahajajo bližje virom Pb, so bile največje vsebnosti izmerjene v letu 2017 ali 2020, ko sta bila vodostaj in pretok nižja kot leta 2013, ali pa so si bile vsebnosti kljub veliki razliki v vodostaju in pretoku podobne v vseh opazovanih letih. V zgornjem toku Meže nismo opazili, da bi višji vodostaj in močnejši pretok neposredno vpli- vala na večje vsebnosti PSE v sedimentih. Dolvod- no od Mežice so nihanja vsebnosti tudi v Meži pre- cejšnja, kar je lahko odraz gradbenih del v strugi dolvodno od Žerjava. Ocenjujemo, da je dinamika onesnaženosti vodotoka Meže vzdolž krajev Črna na Koroškem, Žerjav in Mežica zelo kompleksna. Menimo, da imajo poleg odlagališč rudarskih od- padkov pomemben vpliv tudi ostali razpršeni viri PSE v okolju (onesnažena tla, poplavne ravnice in njihova različna ter kompleksno porazdeljena stopnja onesnaženosti) saj je okolje zaradi več kot 300-letnega izkoriščanja rude močno obremenje- no, kot smo podrobno opisali v uvodnem delu. Poleg tega verjetno vpliva na okolje tudi sedanja industrijska dejavnost. Močnejša vodna erozija struge lahko vpliva na vsebnosti na posamezni lo- kaciji, saj se že odloženi sedimenti v rečnem ko- ritu ob višjem vodostaju ponovno mobilizirajo in prenesejo po toku navzdol ter ponovno odložijo, ko energija toka nekoliko upade. Porazdelitev vsebnosti Zn (sl. 4) je zelo po- dobna porazdelitvi Pb. V vseh opazovanih letih so vsebnosti Zn v sedimentih presegale kritično vrednost v vseh pritokih Meže, razen v Mušeniku (SS-26/7), kjer so bile vsebnosti med mejno in kritično vrednostjo v letih 2013 in 2017, v letu 2020 pa pod mejno vrednostjo. Ravno tako so bile vsebnosti Zn v sedimentih Meže nad kritič- no vrednostjo v vseh opazovanih obdobjih na vseh lokacijah, razen na lokaciji SS-26/3, ki leži gorvodno od večine odlagališč odpadkov in ru- darskih revirjev. Na tej lokaciji so bile vsebno- sti Zn v vseh opazovanih obdobjih med mejno in kritično vrednostjo. Podobno kot v primeru Pb, so bile vsebnosti Zn v pritokih Meže večinoma največje leta 2013 (z izjemo Jazbinskega potoka 0 5 10 15 20 25 30 35 40 45 50 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 13000 14000 15000 SS-26/5 Helenski potok SS-26/7 Mušenik SS-26/8 Pritok 1 / Tributary 1 SS-26/10 Jazbinski potok SS-26/11 Pritok 2 / Tributary2 SS-26/19 Junčarjev potok SS-26/3 Meža SS-26/6 Meža SS-26/9 Meža SS-26/15 Meža SS-26/20 Meža SS-26/21 Meža SS-26/22 Meža Pb v v od i / P b in w at er (µ g/ l) Pb v se di m en tu / P b in se di m en t (m g/ kg ) vzorčna mesta v reki Meži (desno) in njenih pritokih (levo) sampling locations in Meža river (right) and its tributaries (left) Pb v sedimentu / Pb in sediment 2013 (mg/kg) Pb v sedimentu / Pb in sediment 2017 (mg/kg) Pb v sedimentu / Pb in sediment 2020 (mg/kg) Kritična vrednost v sedimentu / Critical value for sediments (mg/kg) Pb v vodi / Pb in water 2017 (µg/l) Pb v vodi / Pb in water 2020 (µg/l) Maksimalna dovoljena vrednost v površinski vodi / Maximum permitted value in surface waters (µg/l) 46200 mg/kg 23100 mg/kg Sl. 3. Pb v sedimentih (v mg/kg) v letih 2013, 2017 in 2020 ter Pb v površinski vodi (v µg/l) v letih 2017 in 2020 (podatki iz leta 2013 in 2017 povzeti po Miler et al., 2022) skupaj z zakonodajnimi vrednostmi. Na levi so prikazane vzorčne lokacije v pritokih, ki spirajo material iz odlagališč, na desni pa v reki Meži. Vzorčne lokacije si na diagramu sledijo kot v naravi po toku navzdol. Fig. 3. Pb in sediments (in mg/kg) in the years 2013, 2017 and 2020 and Pb in surface water (in µg/l) in the years 2017 and 2020 (data from 2013 and 2017 are summarized after Miler et al., 2022). Sampling locations of the tributaries, which wash the material from the waste sites, are presented on the left and of Meža River on the right. Sampling locations on the chart follow each other like in nature downstream. 50 Mateja GOSAR, Špela BAVEC, Miloš MILER & Martin GABERŠEK 0 100 200 300 400 500 600 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 SS-26/5 Helenski potok SS-26/7 Mušenik SS-26/8 Pritok 1 / Tributary1 SS-26/10 Jazbinski potok SS-26/11 Pritok 2 / Tributary 2 SS-26/19 Junčarjev potok SS-26/3 Meža SS-26/6 Meža SS-26/9 Meža SS-26/15 Meža SS-26/20 Meža SS-26/21 Meža SS-26/22 Meža Zn v v od i / Z n in w at er (µ g/ l) Zn v se di m en tu / Z n in se di m en t ( m g/ kg ) vzorčna mesta v reki Meži (desno) in njenih pritokih (levo) sampling locations in Meža river (right) and its tributaries (left) Zn v sedimentu / Zn in sediment 2013 (mg/kg) Zn v sedimentu / Zn in sediment 2017 (mg/kg) Zn v sedimentu / Zn in sediment 2020 (mg/kg) Kritična vrednost v sedimentu / Critical value in sediments (mg/kg) Zn v vodi / Zn in water 2017 (µg/l) Zn v vodi / Zn in water 2020 (µg/l) 2017: 2290 µg/l 2020: 2850 µg/l Sl. 4. Zn v sedimentih (v mg/kg) v letih 2013, 2017 in 2020 ter Zn v površinski vodi (v µg/l) v letih 2017 in 2020 (podatki iz leta 2013 in 2017 povzeti po Miler et al., 2022) skupaj z zakonodajnimi vrednostmi. Na levi so prikazane vzorčne lokacije v pritokih, ki spirajo material iz odlagališč, na desni pa v reki Meži. Vzorčne lokacije si na diagramu sledijo kot v naravi po toku navzdol. Fig. 4. Zn in sediments (in mg/kg) in the years 2013, 2017 and 2020 and Zn in surface water (in µg/l) in the years 2017 and 2020 (data from 2013 and 2017 are summarized after Miler et al., 2022). Sampling locations of the tributaries, which wash the material from the waste sites, are presented on the left and of Meža River on the right. Sampling locations on the chart follow each other like in nature downstream. 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 0 20 40 60 80 100 120 140 SS-26/5 Helenski potok SS-26/7 Mušenik SS-26/8 Pritok 1 / Tributary 1 SS-26/10 Jazbinski potok SS-26/11 Pritok 2 / Tributary 2 SS-26/19 Junčarjev potok SS-26/3 Meža SS-26/6 Meža SS-26/9 Meža SS-26/15 Meža SS-26/20 Meža SS-26/21 Meža SS-26/22 Meža Cd v v od i / C d in w at er (µ g/ l) Cd v se di m en tu / C d in se di m en t ( m g/ kg ) vzorčna mesta v reki Meži (desno) in njenih pritokih (levo) sampling locations in Meža river (right) and its tributaries (left) Cd v sedimentu / Cd in sediment 2013 (mg/kg) Cd v sedimentu / Cd in sediment 2017 (mg/kg) Cd v sedimentu / Cd in sediment 2020 (mg/kg) Kritična vrednost v sedimentu / Critical value in sediments (mg/kg) Cd v vodi / Cd in water 2017 (µg/l) Cd v vodi / Cd in water 2020 (µg/l) 2017: 11.2 µg/l 2020: 11.1 µg/l Sl. 5. Cd v sedimentih (v mg/kg) v letih 2013, 2017 in 2020 ter Cd v površinski vodi (v µg/l) v letih 2017 in 2020 (podatki iz leta 2013 in 2017 povzeti po Miler et al., 2022) skupaj z zakonodajnimi vrednostmi. Na levi so prikazane vzorčne lokacije v pritokih, ki spirajo material iz odlagališč, na desni pa v reki Meži. Vzorčne lokacije si na diagramu sledijo kot v naravi po toku navzdol. Fig. 5. Cd in sediments (in mg/kg) in the years 2013, 2017 and 2020 and Cd in surface water (in µg/l) in the years 2017 and 2020 (data from 2013 and 2017 are summarized after Miler et al., 2022). Sampling locations of the tributaries, which wash the material from the waste sites, are presented on the left and of Meža River on the right. Sampling locations on the chart follow each other like in nature downstream. 51Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov ... Vsebnosti Mo (sl. 6) so v pritokih Meže prese- gale kritično vrednost samo v pritoku 1 (SS-26/8), medtem ko so bile v preostalih pritokih med mejno in kritično vrednostjo oz. pod mejno vrednostjo v Jazbinskem potoku v vseh opazovanih obdobjih, ter v Mušeniku v letu 2017 in 2020. Na lokacijah v Meži so bile vsebnosti Mo večinoma med mejno in kritično vrednostjo, z izjemo lokacije SS-26/22, kjer je bila v letu 2013 vsebnost nad kritično vre- dnostjo, ter lokacije SS-26/21, kjer je bila vrednost v letu 2017 pod mejno vrednostjo. Pod mejno vre- dnostjo so bile tudi vsebnosti Mo na lokaciji SS- 26/3 v vseh opazovanih obdobjih. Glede na vodo- staj in pretok, vsebnosti Mo kažejo podoben trend kot vsebnosti Pb, Zn in Cd; vsebnosti so bile naj- večje v letu 2013 v pritokih (z izjemo Jazbinskega potoka in pritoka 2), v Meži pa na lokacijah SS- 26/15, SS-26/21 in SS-26/22. Vsebnost As (sl. 7) je v pritokih Meže prese- gla kritično vrednost samo v pritoku 1 (SS-26/8) leta 2013, medtem ko je bila v letih 2017 in 2020 med mejno in kritično vrednostjo. Poleg tega so bile vsebnosti med mejno in kritično vrednostjo še v Helenskem potoku (SS-26/5) in Junčarjevem potoku (SS-26/19) leta 2013 ter 2017 ter v pritoku 2 (SS-26/11) v vseh opazovanih obdobjih. Na lokacijah in pritoka 2), torej v času največjega pretoka in najvišjega vodostaja. Vsebnosti Zn v sedimentih Meže so bile v letu 2013 največje na lokaciji SS- 26/15 ter lokacijah SS-26/21 in SS-26/22, ki sta od virov Pb najbolj oddaljeni (dolvodno). Na pre- ostalih lokacijah so bile največje vsebnosti Zn v Meži izmerjene bodisi v letu 2017 ali 2020, ko sta bila pretoka nizka in precej podobna ali pa so si bile vsebnosti podobne v vseh opazovanih letih. Odvisnost vsebnosti Zn od vodostaja in pretoka tako v pritokih kot v Meži kaže podobne lastnosti kot vsebnosti Pb. Vsebnosti Cd (sl. 5) so presegale kritično vred- nost v vseh pritokih Meže, razen v Mušeniku (SS- 26/7) in Jazbinskem potoku (SS-26/10), kjer so bile vsebnosti med mejno in kritično vrednostjo. Na lo- kacijah v Meži velja obratno, saj so bile vsebnosti Cd večinoma med mejno in kritično vrednostjo, z izjemo SS-26/15 v letih 2013 in 2017, SS-26/20 v letu 2017 ter SS-26/22 v letih 2013 in 2017, kjer so vsebnosti presegale kritično vrednost. Glede na vodostaj in pretok, vsebnosti Cd kažejo enak trend kot vsebnosti Pb in Zn; vsebnosti so največje v letu 2013 v pritokih reke Meže (z izjemo Jazbinskega potoka in pritoka 2) ter v Meži na lokacijah SS- 26/21 in SS-26/22. 0 2 4 6 8 10 12 14 16 18 20 0 50 100 150 200 250 300 SS-26/5 Helenski potok SS-26/7 Mušenik SS-26/8 Pritok 1 / Tributary 1 SS-26/10 Jazbinski potok SS-26/11 Pritok 2 / Tributary 2 SS-26/19 Junčarjev potok SS-26/3 Meža SS-26/6 Meža SS-26/9 Meža SS-26/15 Meža SS-26/20 Meža SS-26/21 Meža SS-26/22 Meža M o v vo di / M o in w at er (µ g/ l) M o v se di m en tu / M o in se di m en t ( m g/ kg ) vzorčna mesta v reki Meži (desno) in njenih pritokih (levo) sampling locations in Meža river (right) and its tributaries (left) Mo v sedimentu / Mo in sediment 2013 (mg/kg) Mo v sedimentu / Mo in sediment 2017 (mg/kg) Mo v sedimentu / Mo in sediment 2020 (mg/kg) Kritična vrednost v sedimentu / Critical value in sediments (mg/kg) Mo v vodi / Mo in water 2017 (µg/l) Mo v vodi / Mo in water 2020 (µg/l) Maksimalna dovoljena vrednost v površinski vodi / Maximum permitted value in surface waters (µg/l) 200 µg/l3310 mg/kg 749 mg/kg 361 mg/kg Sl. 6. Mo v sedimentih (v mg/kg) v letih 2013, 2017 in 2020 ter Mo v površinski vodi (v µg/l) v letih 2017 in 2020 (podatki iz leta 2013 in 2017 povzeti po Miler et al., 2022) skupaj z zakonodajnimi vrednostmi. Na levi so prikazane vzorčne lokacije v pritokih, ki spirajo material iz odlagališč, na desni pa v reki Meži. Vzorčne lokacije si na diagramu sledijo kot v naravi po toku navzdol. Fig. 6. Mo in sediments (in mg/kg) in the years 2013, 2017 and 2020 and Mo in surface water (in µg/l) in the years 2017 and 2020 (data from 2013 and 2017 are summarized after Miler et al., 2022). Sampling locations of the tributaries, which wash the material from the waste sites, are presented on the left and of Meža River on the right. Sampling locations on the chart follow each other like in nature downstream. 52 Mateja GOSAR, Špela BAVEC, Miloš MILER & Martin GABERŠEK 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 0 10 20 30 40 50 60 70 80 SS-26/5 Helenski potok SS-26/7 Mušenik SS-26/8 Pritok 1 / Tributary 1 SS-26/10 Jazbinski potok SS-26/11 Pritok 2 / Tributary 2 SS-26/19 Junčarjev potok SS-26/3 Meža SS-26/6 Meža SS-26/9 Meža SS-26/15 Meža SS-26/20 Meža SS-26/21 Meža SS-26/22 Meža As v v od i / A s i n w at er (µ g/ l) As v se di m en tu / A s i n se di m en t ( m g/ kg ) vzorčna mesta v reki Meži (desno) in njenih pritokih (levo) sampling locations in Meža river (right) and its tributaries (left) As v sedimentu / As in sediment 2013 (mg/kg) As v sedimentu / As in sediment 2017 (mg/kg) As v sedimentu / As in sediment 2020 (mg/kg) Kritična vrednost v sedimentu / Critical value in sediments (mg/kg) As v vodi / As in water 2017 (µg/l) As v vodi / As in water 2020 (µg/l) 21 µg/l Sl. 7. As v sedimentih (v mg/kg) v letih 2013, 2017 in 2020 ter As v površinski vodi (v µg/l) v letih 2017 in 2020 (podatki iz leta 2013 in 2017 povzeti po Miler et al., 2022) skupaj z zakonodajnimi vrednostmi. Na levi so prikazane vzorčne lokacije v pritokih, ki spirajo material iz odlagališč, na desni pa v reki Meži. Vzorčne lokacije si na diagramu sledijo kot v naravi po toku navzdol. Fig. 7. As in sediments (in mg/kg) in the years 2013, 2017 and 2020 and As in surface water (in µg/l) in the years 2017 and 2020 (data from 2013 and 2017 are summarized after Miler et al., 2022). Sampling locations of the tributaries, which wash the material from the waste sites, are presented on the left and of Meža River on the right. Sampling locations on the chart follow each other like in nature downstream. 0 5 10 15 20 25 30 35 0 100 200 300 400 500 600 700 SS-26/5 Helenski potok SS-26/7 Mušenik SS-26/8 Pritok 1 / Tributary 1 SS-26/10 Jazbinski potok SS-26/11 Pritok 2 / Tributary 2 SS-26/19 Junčarjev potok SS-26/3 Meža SS-26/6 Meža SS-26/9 Meža SS-26/15 Meža SS-26/20 Meža SS-26/21 Meža SS-26/22 Meža Ba v v od i/ Ba in w at er (µ g/ l) Ba v se di m en tu / Ba in se di m en t ( m g/ kg ) vzorčna mesta v reki Meži (desno) in njenih pritokih (levo) sampling locations in Meža river (right) and its tributaries (left) Ba v sedimentu / Ba in sediment 2013 (mg/kg) Ba v sedimentu / Ba in sediment 2017 (mg/kg) Ba v sedimentu / Ba in sediment 2020 (mg/kg) Kritična vrednost v sedimentu / Critical value in sediments (mg/ kg) Ba v vodi / Ba in water 2017 (µg/l) Ba v vodi / Ba in water 2020 (µg/l) Sl. 8. Ba v sedimentih (v mg/kg) v letih 2013, 2017 in 2020 ter Ba v površinski vodi (v µg/l) v letih 2017 in 2020 (podatki iz leta 2013 in 2017 povzeti po Miler et al., 2022) skupaj z zakonodajnimi vrednostmi. Na levi so prikazane vzorčne lokacije v pritokih, ki spirajo material iz odlagališč, na desni pa v reki Meži. Vzorčne lokacije si na diagramu sledijo kot v naravi po toku navzdol. Fig. 8. Ba in sediments (in mg/kg) in the years 2013, 2017 and 2020 and Ba in surface water (in µg/l) in the years 2017 and 2020 (data from 2013 and 2017 are summarized after Miler et al., 2022). Sampling locations of the tributaries, which wash the material from the waste sites, are presented on the left and of Meža River on the right. Sampling locations on the chart follow each other like in nature downstream. 53Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov ... 0 5 10 15 20 25 30 35 40 45 50 SS-26/5 Helenski potok SS-26/7 Mušenik SS-26/8 Pritok 1 / Tributary 1 SS-26/10 Jazbinski potok SS-26/11 Pritok 2 / Tributary 2 SS-26/19 Junčarjev potok SS-26/3 Meža SS-26/6 Meža SS-26/9 Meža SS-26/15 Meža SS-26/20 Meža SS-26/21 Meža SS-26/22 Meža Cr v se di m en tu / Cr in se di m en t ( m g/ kg ) vzorčna mesta v reki Meži (desno) in njenih pritokih (levo) sampling locations in Meža river (right) and its tributaries (left) Cr v sedimentu / Cr in sediment 2013 (mg/kg) Cr v sedimentu / Cr in sediment 2017 (mg/kg) Cr v sedimentu / Cr in sediment 2020 (mg/kg) Kritična vrednost v sedimentu / Critical value in sediments (mg/kg) 380 µg/l 0 0,05 0,1 0,15 0,2 0,25 0 2 4 6 8 10 12 14 SS-26/5 Helenski potok SS-26/7 Mušenik SS-26/8 Pritok 1 / Tributary 1 SS-26/10 Jazbinski potok SS-26/11 Pritok 2 / Tributary 2 SS-26/19 Junčarjev potok SS-26/3 Meža SS-26/6 Meža SS-26/9 Meža SS-26/15 Meža SS-26/20 Meža SS-26/21 Meža SS-26/22 Meža Co v v od i/ Co in w at er (µ g/ l) Co v se di m en tu / Co in se di m en t ( m g/ kg ) vzorčna mesta v reki Meži (desno) in njenih pritokih (levo) sampling locations in Meža river (right) and its tributaries (left) Co v sedimentu / Co in sediment 2013 (mg/kg) Co v sedimentu / Co in sediment 2017 (mg/kg) Co v sedimentu / Co in sediment 2020 (mg/kg) Kritična vrednost v sedimentu / Critical value in sediments (mg/kg) Co v vodi / Co in water 2017 (µg/l) Co v vodi / Co in water 2020 (µg/l) Maksimalna dovoljena vrednost v površinski vodi / Maximum permitted value in surface waters (µg/l) 240 µg/l 2.9 µg/l Sl. 10. Cr v sedimentih (v mg/kg) v letih 2013, 2017 in 2020 (podatki iz leta 2013 in 2017 povzeti po Miler et al., 2022) skupaj z zakonodajnimi vrednostmi. Na levi so prikazane vzorčne lokacije v pritokih, ki spirajo material iz odlagališč, na desni pa v reki Meži. Vzorčne lokacije si na diagramu sledijo kot v naravi po toku navzdol. Fig. 10. Cr in sediments (in mg/kg) in the years 2013, 2017 and 2020 (data from 2013 and 2017 are summarized after Miler et al., 2022). Sampling locations of the tributaries, which wash the material from the waste sites, are presented on the left and of Meža River on the right. Sampling locations on the chart follow each other like in nature downstream Sl. 9. Co v sedimentih (v mg/kg) v letih 2013, 2017 in 2020 ter Co v površinski vodi (v µg/l) v letih 2017 in 2020 (podatki iz leta 2013 in 2017 povzeti po Miler et al., 2022) skupaj z zakonodajnimi vrednostmi. Na levi so prikazane vzorčne lokacije v pritokih, ki spirajo material iz odlagališč, na desni pa v reki Meži. Vzorčne lokacije si na diagramu sledijo kot v naravi po toku navzdol. Fig. 9. Co in sediments (in mg/kg) in the years 2013, 2017 and 2020 and Co in surface water (in µg/l) in the years 2017 and 2020 (data from 2013 and 2017 are summarized after Miler et al., 2022). Sampling locations of the tributaries, which wash the material from the waste sites, are presented on the left and of Meža River on the right. Sampling locations on the chart follow each other like in nature downstream. 54 Mateja GOSAR, Špela BAVEC, Miloš MILER & Martin GABERŠEK v Meži so vsebnosti As nihale med mejno in kri- tično vrednostjo na lokacijah SS-26/15 in SS-26/22 leta 2013 ter 2017, na lokaciji SS-26/20 leta 2017 in na lokaciji SS-26/21 leta 2013. Glede na vodostaj in pretok, vsebnosti As v pritokih kažejo delno podo- ben trend kot vsebnosti Pb, Zn in Cd, z izjemo, da se vsebnosti As z višjim vodostajem in pretokom poleg Jazbinskega potoka in pritoka 2 ne povečajo tudi v Junčarjevem potoku. Na lokacijah v Meži je trend enak, vsebnosti As so bile nekoliko večje leta 2013 na lokacijah SS-26/21 in SS-26/22, ki sta od virov Pb in ostalih PSE v okolju najbolj oddaljeni. Vsebnosti preostalih PSE (Ba, Co, Cr, Cu, Ni, Hg; sl. 8–13) so večinoma na nivoju naravnega ozadja in le izjemoma presegajo mejne vrednosti. Vsebnosti Ba (sl. 8) so bile nad mejno vrednostjo v pritoku 1 (SS-26/8) v letu 2013 ter v pritoku 2 (SS-26/11) in Junčarjevem potoku v vseh opazo- vanih obdobjih. Vsebnost Hg je bila nad mejno vrednostjo samo leta 2013 v Meži na lokaciji SS- 26/9 (sl. 13), Cu pa leta 2017 v Meži na lokaciji SS-26/9 in pritoku 1 (SS-26/11) leta 2020 (sl. 11). Za omenjene PSE je večinoma značilno, da njiho- ve vsebnosti v opazovanem obdobju oz. ob spre- menljivem vodostaju ter pretoku ne nihajo močno, ampak so na istem vzorčnem mestu relativno po- dobne. Kaže, da se z višjim vodostajem in večjim pretokom še najbolj povečajo vsebnosti Cr na loka- ciji SS-26/22 (sl. 10) in vsebnosti Hg na vzorčnih mestih SS-26/9, SS-26/20, SS-26/22 (sl. 13), vse v Meži. Nihanja v vsebnostih Ba, Co, Cr, Cu, Ni in Hg na posameznih vzorčnih mestih skozi leta so v primerjavi z nihanji vsebnosti Pb, Zn, Cd, Mo in As precej manj izrazita. Rezultati nazorno prikazujejo (sl. 3–8, tabe- la 2), da so vsebnosti Pb, Zn, Mo, Cd ter deloma tudi As v sedimentih pritokov močno nad geoke- mičnim ozadnjem. Vsebnosti Cd, Pb in Zn v sedi- mentih vodotokov, ki odvodnjavajo odlagališča, z izjemo Mušenika in Jazbinskega potoka ter Cd v Junčarjevem potoku (2017, 2020), za več kot 2 × presegajo kritične vrednosti v vseh opazovanih letih. Poglavitni vzrok temu je neustrezno stanje odlagališč. Odlagališča so bila sanirana pred več kot 25 leti, potem pa niso bila več vzdrževana. Na nekaterih lokacijah so brežine odlagališč strme in neporasle, odvodnjavanje ni pravilno urejeno (Gosar in sodelavci, 2021). Zaradi tega ima erozija odlagališč močan vpliv na dotok materiala v prito- ke Meže in nadalje po toku navzdol. 0 1 2 3 4 5 6 7 0 10 20 30 40 50 60 70 80 90 100 SS-26/5 Helenski potok SS-26/7 Mušenik SS-26/8 Pritok 1 / Tributary 1 SS-26/10 Jazbinski potok SS-26/11 Pritok 2 / Tributary 2 SS-26/19 Junčarjev potok SS-26/3 Meža SS-26/6 Meža SS-26/9 Meža SS-26/15 Meža SS-26/20 Meža SS-26/21 Meža SS-26/22 Meža Cu v v od i/ Cu in w at er (µ g/ l) Cu v se di m en tu / Cu in se di m en t ( m g/ kg ) vzorčna mesta v reki Meži (desno) in njenih pritokih (levo) sampling locations in Meža river (right) and its tributaries (left) Cu v sedimentu / Cu in sediment 2013 (mg/kg) Cu v sedimentu / Cu in sediment 2017 (mg/kg) Cu v sedimentu / Cu in sediment 2020 (mg/kg) Kritična vrednost v sedimentu / Critical value in sediments (mg/kg) Cu v vodi / Cu in water 2017 (µg/l) Cu v vodi / Cu in water 2020 (µg/l) Maksimalna dovoljena vrednost v površinski vodi / Maximum permitted value in surface waters (µg/l) 300 mg/kg 74 µg/l Sl. 11. Cu v sedimentih (v mg/kg) v letih 2013, 2017 in 2020 ter Cu v površinski vodi (v µg/l) v letih 2017 in 2020 (podatki iz leta 2013 in 2017 povzeti po Miler et al., 2022) skupaj z zakonodajnimi vrednostmi. Na levi so prikazane vzorčne lokacije v pritokih, ki spirajo material iz odlagališč, na desni pa v reki Meži. Vzorčne lokacije si na diagramu sledijo kot v naravi po toku navzdol. Fig. 11. Cu in sediments (in mg/kg) in the years 2013, 2017 and 2020 and Cu in surface water (in µg/l) in the years 2017 and 2020 (data from 2013 and 2017 are summarized after Miler et al., 2022). Sampling locations of the tributaries, which wash the material from the waste sites, are presented on the left and of Meža River on the right. Sampling locations on the chart follow each other like in nature downstream. 55Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov ... Vsebnosti PSE so tudi v sedimentih Meže zelo velike in na splošno močno nihajo med posame- znimi vzorčnimi mesti in med posameznimi leti, v katerih so bile izvedene meritve. V zgornjem toku je vpliv odlagališč rudarskih odpadkov na vseb- nosti PSE v sedimentih Meže bolj izrazit, medtem ko je dolvodno od Mežice zakrit zaradi preostalih virov, verjetno zaradi prispevka sedanje industrij- ske dejavnosti (Miler et al., 2022) in erozije one- snaženih tal ter poplavnih ravnic. Velik vpliv ima- jo tudi hidrološki pogoji. Pritoki imajo večinoma hudourniški značaj, za reko Mežo pa je značilno, da ima ob visokem vodostaju velik pretok, zaradi česar delno erodira lastno korito in v njem odlože- ne sedimente. Glede na hidrološke pogoje v času vzorčenja in med različnimi leti so bile v Meži v 30 % dosežene ugodne razmere za erozijo in tran- sport sedimenta obremenjenega s PSE (Miler et al., 2022). Zaradi tega se del onesnaženih sedimentov v obliki suspenzije ali po dnu struge transportira dolvodno v reko Dravo in dalje. To nakazuje tudi zelo drobna zrnavost trdnih nosilcev PSE v sedi- mentu in materialu odlagališč (Miler in sodelav- ci, 2022) in potrjujejo visoke vrednosti nekaterih PSE v sedimentih Drave (Fux & Gosar, 2007; Ga- beršek & Gosar, 2023) dolvodno od pritoka Meže. Akumulacijo onesnaženih sedimentov predstavlja- jo poplavne ravnice v srednjem in spodnjem toku Meže, ki jih močna erozija ob izjemnih dogodkih lahko erodira. Hudourniški značaj in izredno erozijsko moč Meže ter njenih pritokov smo opazovali tudi v za- četku avgusta 2023, ko je v skupno 72 urah, od 3. avgusta zvečer do 6. avgusta zjutraj, v večjem delu Slovenije padlo med 100 in 300 mm dež- ja (ARSO, 2023), kar je povzročilo katastrofalne poplave in številne plazove, med drugim tudi v porečju Meže. Ob izrednem padavinskem in posle- dično poplavnem ter erozijskem dogodku so bile v mežiški dolini premeščene ogromne količine mate- riala, predvsem iz predhodno odloženih poplavnih ravnic, melišč, tal in tudi odlagališč rudarskih od- padkov. Mnogo premeščenega in nižje odloženega materiala, predvsem drobnozrnatega, je zagotovo vsebovalo velike vsebnosti PSE. To dokazujejo tudi podatki, ki jih je objavila Agencija republike Slovenije za okolje (ARSO) za vsebnosti nekaterih PSE v sedimentih, ki so se ob poplavah odložili 0 0,5 1 1,5 2 2,5 3 3,5 4 0 5 10 15 20 25 30 35 40 SS-26/5 Helenski potok SS-26/7 Mušenik SS-26/8 Pritok 1 / Tributary 1 SS-26/10 Jazbinski potok SS-26/11 Pritok 2 / Tributary 2 SS-26/19 Junčarjev potok SS-26/3 Meža SS-26/6 Meža SS-26/9 Meža SS-26/15 Meža SS-26/20 Meža SS-26/21 Meža SS-26/22 Meža N i v v od i/ N i i n w at er (µ g/ l) N i v se di m en tu / N i i n se di m en t ( m g/ kg ) vzorčna mesta v reki Meži (desno) in njenih pritokih (levo) sampling locations in Meža river (right) and its tributaries (left) Ni v sedimentu / Ni in sediment 2013 (mg/kg) Ni v sedimentu / Ni in sediment 2017 (mg/kg) Ni v sedimentu / Ni in sediment 2020 (mg/kg) Kritična vrednost v sedimentu / Critical value in sediments (mg/kg) Ni v vodi / Ni in water 2017 (µg/l) Ni v vodi / Ni in water 2020 (µg/l) Maksimalna dovoljena vrednost v površinski vodi / Maximum permitted value in surface waters (µg/l) 34 µg/l210 mg/kg Sl. 12. Ni v sedimentih (v mg/kg) v letih 2013, 2017 in 2020 ter Ni v površinski vodi (v µg/l) v letih 2017 in 2020 (podatki iz leta 2013 in 2017 povzeti po Miler et al., 2022) skupaj z zakonodajnimi vrednostmi. Na levi so prikazane vzorčne lokacije v pritokih, ki spirajo material iz odlagališč, na desni pa v reki Meži. Vzorčne lokacije si na diagramu sledijo kot v naravi po toku navzdol. Fig. 12. Ni in sediments (in mg/kg) in the years 2013, 2017 and 2020 and Ni in surface water (in µg/l) in the years 2017 and 2020 (data from 2013 and 2017 are summarized after Miler et al., 2022). Sampling locations of the tributaries, which wash the material from the waste sites, are presented on the left and of Meža River on the right. Sampling locations on the chart follow each other like in nature downstream. 56 Mateja GOSAR, Špela BAVEC, Miloš MILER & Martin GABERŠEK (internet 1). Največjo vsebnost PSE v naplavljenem sedimentu so določili v Poljani (3800 mg/kg Zn, 590 mg/kg Pb, 25 mg/kg Cd, (podatki povzeti iz internet 1)). Vsebnosti PSE v sedimentih so velike in pričakovane, glede na podatke, ki jih obravna- vamo v tem prispevku. Dogodek tovrstnega obsega je zagotovo močno spremenil geokemične lastnosti preučevanega območja, zato bo v bodoče zanimivo izvesti dodatne raziskave in opraviti primerjavo s podatki predstavljenimi v tem prispevku. Vrednosti fizikalno-kemičnih parametrov in vsebnosti PSE v površinski vodi Terenske meritve osnovnih fizikalno-kemičnih parametrov vode (pH, T, Eh, EC in DO) na posa- meznih vzorčnih mestih so podane v tabeli 3. Iz- merjeni fizikalno-kemični parametri so osnovni indikatorji stanja vode. Pomembno vplivajo na ob- našanje trdnih snovi v vodi, tudi tistih, ki vsebu- jejo PSE ter posledično na vsebnosti PSE v vodah. Mejne vrednosti osnovnih fizikalno-kemičnih pa- rametrov v površinskih vodah v uredbah niso po- sebej predpisane. Vrednosti pH so bile leta 2020 med 7,4 in 8,6, kar je nekoliko manj kot leta 2017 (8,1–8,8). Vzrok temu je lahko izvedba meritev v različnih letnih časih. Leta 2017 smo meritve izvedli poleti, ko je sproščanje organskih snovi iz rastlin v vodo in- tenzivnejše, kot jeseni, v času katere smo meritve izvajali leta 2020. V pritokih, ki odvodnjavajo odlagališča, je bila v obeh letih najmanjša vred- nost izmerjena v pritoku 2 (SS-26/11), največja pa leta 2017 v Mušeniku (SS-26/7), leta 2020 pa v Helenskem potoku (SS-26/5). V reki Meži so se vrednosti pH gibale med 7,4 in 8,4. Vrednosti Eh so bile med 478 in 592 mV. Najmanjša vrednost v pritokih je bila izmerjena v Mušeniku (SS-26/7), največja pa v pritoku 2 (SS-26/11). Vrednosti v Meži so bile med 487 in 592 mV. Električna pre- vodnost (EC), ki odraža delež raztopljenih trd- nih snovi v vodi oziroma je neposredno odvisna od ionskih oblik elementov, se v meritvah gibl- je med 183 in 685 µS/cm, kar je zelo podobno vrednostim iz leta 2017 (181–609 µS/cm). V obeh letih smo najmanjše vrednosti v pritokih izmeri- li v Jazbinskem potoku (SS-26/10), največji pa v 0 0,2 0,4 0,6 0,8 1 1,2 1,4 SS-26/5 Helenski potok SS-26/7 Mušenik SS-26/8 Pritok 1 / Tributary 1 SS-26/10 Jazbinski potok SS-26/11 Pritok 2 / Tributary 2 SS-26/19 Junčarjev potok SS-26/3 Meža SS-26/6 Meža SS-26/9 Meža SS-26/15 Meža SS-26/20 Meža SS-26/21 Meža SS-26/22 Meža Hg v se di m en tu / Hg in se di m en t ( m g/ kg ) vzorčna mesta v reki Meži (desno) in njenih pritokih (levo) sampling locations in Meža river (right) and its tributaries (left) Hg v sedimentu / Hg in sediment 2013 (mg/kg) Hg v sedimentu / Hg in sediment 2017 (mg/kg) Hg v sedimentu / Hg in sediment 2020 (mg/kg) Kritična vrednost v sedimentu/Critical value in sediments (mg/kg) 10 mg/kg Sl. 13. Hg v sedimentih (v mg/kg) v letih 2013, 2017 in 2020 (podatki iz leta 2013 in 2017 povzeti po Miler et al., 2022) skupaj z zakonodaj- nimi vrednostmi. Na levi so prikazane vzorčne lokacije v pritokih, ki spirajo material iz odlagališč, na desni pa v reki Meži. Vzorčne lokacije si na diagramu sledijo kot v naravi po toku navzdol. Fig. 13. Hg in sediments (in mg/kg) in the years 2013, 2017 and 2020 (data from 2013 and 2017 are summarized after Miler et al., 2022). Sampling locations of the tributaries, which wash the material from the waste sites, are presented on the left and of Meža River on the right. Sampling locations on the chart follow each other like in nature downstream. 57Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov ... pritoku 2 (SS-26/11). V reki Meži so bile vrednosti v splošnem nekoliko manjše. Koncentracije v vodi raztopljenega kisika (DO) so bile leta 2020 (10,5– 11,4 mg/l) malenkost večje, kot so bile leta 2017 (9,3–11,2 mg/l). V pritokih je bila vrednost DO v obeh letih najmanjša v Junčarjevem potoku (SS- 26/19). Največjo vrednost DO v pritokih smo leta 2017 ugotovili v pritoku 2 (SS-26/11), leta 2020 pa v Helenskem potoku (SS-26/5). Vrednosti v Meži so bile v območju med 10,5 in 11,4 mg/l. Glede na izmerjene vrednosti parametrov pH, Eh in DO je okolje v večini vodotokov na območju obravnavanih odlagališč rudarskih odpadkov nevtralno do rahlo bazično in relativno dobro prezračeno. V takih pogojih so trdni nosilci PSE Pb-karbonati in sulfidi ter Fe-oksihidroksidi veči- noma stabilni, medtem ko so Zn-karbonati in sulfi- di ter Fe-oksihidroksi sulfati s Pb in Zn nestabilni, zaradi česar se lahko del PSE iz njih izloči v vodo. Vsebnosti 11 potencialno strupenih elementov (As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb in Zn) v obravnavanih vzorcih površinskih vod so podane v tabeli 4. Za vrednotenje koncentracij PSE v ob- ravnavanih vodah na vzorčnih mestih smo upora- bili mejne vrednosti, določene z Uredbo o stanju površinskih voda (Uradni list RS, št. 14/09, 98/10, 96/13, 24/16 in 44/22 – ZVO-2). Tako so v tabeli 4 navedene vrednosti naravnega ozadja (NO) in naj- višje dovoljene koncentracije za površinske vode. Z rdečo barvo so označene koncentracije, ki presega- jo normativ za površinske vode. Vsebnost kadmija (Cd) je v normativu za površinske vode odvisna od trdote vode, ki je razdeljena v pet razredov. Ravno tako je od trdote vode odvisna vrednost cinka (Zn) in je razdeljena v tri razrede. Glede na meritve terenskih parametrov in litološko sestavo smo pri- vzeli, da je trdota vode v obravnavanih vzorcih za Cd od 100 do < 200 mg CaCO3/l, s čimer je nor- Tabela 3. Terenske meritve osnovnih fizikalno-kemičnih parametrov vode (pH, Eh, EC, DO, T). Table 3. Field measurments of basic physico-chemical parametres of water (pH, Eh, EC, DO, T). Vzorčno mesto / Sampling site Leto / Year Vodotok / Watercourse pH Eh (mV) EC (µS/cm) DO (%) DO (mg/l) T (°C) SS-26/3 20171 Meža 8,54 / 180,9 101,6 11,06 8,5 2020 7,37 592 182,6 101,7 11,43 7,4 SS-26/5 20171 Helenski potok 8,74 / 376,5 100,9 10,67 9,7 2020 8,55 533 465,7 101,6 11,27 7,7 SS-26/6 20171 Meža 8,62 / 191,8 102,6 10,99 9,3 2020 7,97 534 200,0 101,1 11,26 7,6 SS-26/7 20171 Mušenik 8,79 / 362,8 100,1 10,34 11,0 2020 8,50 478 436,7 100,5 10,95 8,6 SS-26/8 20171 pritok 1/ tributary 1 8,77 / 348,1 100,7 10,39 10,7 2020 8,46 502 410,1 100,2 10,90 8,8 SS-26/9 20171 Meža 8,12 / 260,9 96,6 9,46 13,4 2020 8,36 506 270,0 99,5 10,90 8,5 SS-26/10 20171 Jazbinski potok 8,68 / 319,6 101,3 11,16 12,4 2020 8,40 493 355,7 100,7 11,02 8,6 SS-26/11 20171 pritok 2/ tributary 2 8,24 / 609,0 100,7 11,18 7,9 2020 7,90 567 684,9 96,8 10,70 8,2 SS-26/15 20171 Meža 8,58 / 324,4 100,1 9,42 15,5 2020 8,42 487 383,7 97,9 10,55 9,6 SS-26/19 20171 Junčarjev potok 8,68 / 348,7 99,2 9,95 12,6 2020 8,53 537 401,5 97,9 10,63 9,2 SS-26/20 20171 Meža 8,64 / 324,7 100,8 9,28 16,6 2020 8,39 511 373,2 98,5 10,65 9,5 SS-26/21 20171 Meža 8,61 / 331,4 99,6 9,32 16,0 2020 8,34 490 376,4 98,3 10,57 9,9 SS-26/22 20171 Meža 8,71 / 298,0 99,4 9,48 15,0 2020 8,26 503 325,7 97,1 10,46 10,0 58 Mateja GOSAR, Špela BAVEC, Miloš MILER & Martin GABERŠEK mativ za Cd 0,9 + NO μg/l ter za Zn ≥ 100 mg Ca- CO3/l, s čimer je normativ za Zn 520 + NO μg/l. Izmerjene vsebnosti Pb v vzorcih vode (tabe- la 4, sl. 3) so leta 2017 presegale normativ za povr- šinske vode za svinec (14 μg/l) na vzorčnih mestih v Helenskem potoku (SS-26/5; 47,1 μg/l), v prito- ku 2 (SS-26/11; 38,1 μg/l) in v Junčarjevem po- toku (SS-26/19; 33,8 μg/). Preseganje normativne vrednosti in dobro ujemanje z vrednostmi iz leta 2017 na omenjenih treh lokacijah smo ugotovili tudi leta 2020. Vsebnosti Pb na vzorčnih mestih SS-26/5 (28 μg/l) in SS-26/19 (15,4 μg/l) sta bili le nekoliko manjši kot leta 2017, na vzorčnem mestu SS-26/11 pa rahlo večja (44,4 μg/l). Na vseh omenjenih lokacijah smo tudi v sedimentih v obeh letih ugotovili močno povečane vsebnosti Pb, ki presegajo kritične vrednosti za Pb. Tabela 4. Vsebnosti As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb in Zn (V μg/l) v površinskih vodah. Table 4. Contents of As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb and Zn (in μg/l) in surface waters. Vzorčno mesto / Sampling site Leto / Year Vodotok / Watercourse As Ba Cd Co Cr Cu Hg Mo Ni Pb Zn SS-26/3 20171 Meža 0,88 7,3 0,02 0,013 < 0,5 0,2 < 0,2 1,0 < 0,3 0,18 3,3 2020 1,19 7,1 0,02 0,014 < 0,5 0,2 < 0,2 0,9 < 0,3 0,17 3,7 SS-26/5 20171 Helenski potok 0,46 12,2 0,45 0,049 < 0,5 2,1 < 0,2 1,7 0,4 47,1 83,6 2020 0,49 8,5 0,45 0,067 < 0,5 0,7 < 0,2 0,9 0,4 28,0 88,4 SS-26/6 20171 Meža 0,94 8,1 0,09 0,016 < 0,5 0,3 < 0,2 1,2 < 0,3 1,90 10,6 2020 1,19 7,6 0,10 0,016 < 0,5 0,2 < 0,2 1,0 < 0,3 1,23 12,4 SS-26/7 20171 Mušenik 0,30 6,3 0,04 0,026 < 0,5 0,4 < 0,2 1,5 < 0,3 2,69 8,1 2020 0,38 6,0 0,05 0,026 < 0,5 0,4 < 0,2 1,0 0,3 3,57 8,6 SS-26/8 20171 pritok 1/ tributary 1 0,20 11,2 < 0,01 0,016 < 0,5 0,2 < 0,2 1,7 < 0,3 < 0,01 < 0,5 2020 0,24 13,1 0,04 0,024 < 0,5 0,4 < 0,2 1,2 2,0 5,65 11,6 SS-26/9 20171 Meža 0,51 12,6 0,10 0,026 < 0,5 0,7 < 0,2 1,8 0,4 0,89 19,7 2020 0,71 12,8 0,10 0,033 < 0,5 0,4 < 0,2 1,5 < 0,3 0,56 4,9 SS-26/10 20171 Jazbinski p. 0,33 17,7 0,15 0,016 < 0,5 0,5 < 0,2 2,1 < 0,3 2,15 43,3 2020 0,34 16,0 0,04 0,016 < 0,5 0,3 < 0,2 1,7 0,3 3,02 74,4 SS-26/11 20171 pritok 2/ tributary 2 0,70 9,1 11,20 0,034 < 0,5 0,5 < 0,2 5,6 1,3 38,1 2290 2020 1,02 7,3 11,10 0,052 < 0,5 0,6 < 0,2 4,2 1,6 44,4 2850 SS-26/15 20171 Meža 0,48 17,4 1,14 0,143 < 0,5 6,1 < 0,2 2,3 3,1 5,84 42,9 2020 1,23 16,7 1,45 0,140 < 0,5 1,4 < 0,2 10,5 2,4 4,17 59,0 SS-26/19 20171 Junčarjev potok 0,52 29,4 0,38 0,030 < 0,5 0,6 < 0,2 2,9 2,4 33,8 162 2020 0,56 15,2 0,09 0,032 < 0,5 0,5 < 0,2 1,6 0,5 15,4 78 SS-26/20 20171 Meža 0,54 18,6 1,17 0,126 < 0,5 6,1 < 0,2 2,5 3,0 7,68 44,8 2020 1,35 18,1 1,78 0,175 < 0,5 1,9 < 0,2 8,2 3,3 4,28 65,1 SS-26/21 20171 Meža 0,61 21,2 0,91 0,089 < 0,5 4,2 < 0,2 2,5 2,4 4,86 38,6 2020 1,27 20,1 1,21 0,110 < 0,5 0,9 < 0,2 6,1 2,2 2,98 53,9 SS-26/22 20171 Meža 0,68 22,0 0,47 0,042 < 0,5 3,5 < 0,2 2,5 1,7 1,80 20,5 2020 1,18 20,5 0,65 0,028 < 0,5 0,7 < 0,2 3,9 1,1 0,64 41,4 Naravno ozadje / Natural background (NO; μg/l)2 / / 0,04 0,100 / 1,0 0,0025 / / / 4,2 Površinske vode-največja dovoljena koncentracija / Surface waters-highest permissible level (μg/l)3 21 / r.4 a: 0,9+NO 2,8 +NO 160 73 +NO 0,07 +NO 200 34 14 520b +NO Odpadne vode (neposredno v vodo) Waste water (directly in water) (μg/l)4 100 5000 25 30 500 500 5 1000 500 500 2000 1Podatki povzeti po Miler et al. (2022) / Data after Miler et al. (2022) 2, 3Uradni list RS, št. 14/09, 98/10, 96/13, 24/16 in 44/22 – ZVO-2. Uredba o stanju površinskih voda / Decree on surface water status 4Uradni list RS, št. 64/12, 64/14, 98/15, 44/22 – ZVO-2, 75/22 in 157/22. Decree on the emission of substances and heat when discharging waste water into waters and the public sewage system. 59Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov ... Vsebnosti Zn (tabela 4, sl. 4) so leta 2017 prese- gale normativ za površinske vode za Zn (524,2 μg/l) samo v pritoku 2 (SS-26/11; 2290 μg/l). Podobno stanje smo ugotovili tudi leta 2020, ko je bila vseb- nost Zn na vzorčnem mestu SS-26/11 nekoliko večja (2850 μg/l). Tudi vsebnosti Zn v sedimentu na istem vzorčnem mestu sta v obeh letih močno presegali kritično vrednost za Zn. Vsebnosti Cd (tabela 4, sl. 5) so leta 2017 presegale normativ za površinske vode za Cd (0,94 μg/l) na treh vzorčnih mestih: v pritoku 2 (SS-26/11; 11,2 μg/l) ter na dveh lokacijah v Meži (SS-26/15; 1,14 μg/l in SS-26/20; 1,17 μg/l). Na vseh omenjenih lokacijah so tudi vsebnosti Cd v sedimentih presegale pripadajočo kritično vred- nost. Tudi v letu 2020 smo ugotovili presegan- je normativa za površinske vode za Cd v pritoku 2 (SS-26/11; 11,1 μg/l) ter v Meži na lokacijah SS-26/15 (1,45 μg/l) in SS-26/20 (1,78 μg/l). Dodatno smo leta 2020 ugotovili preseganje še na eni lokaciji v Meži (SS-26/21; 1,21 μg/l). Vsebnosti Cd v sedimentu v letu 2020 so bile na vzorčnem mestu SS-26/11 nad kritično vrednostjo za Cd, na preostalih treh vzorčnih mestih pa med mejno in kritično vrednostjo. Vsebnosti Mo (sl. 6), As (sl. 7), Ba (sl. 8), Co (sl. 9), Cr (sl. 10), Cu (sl. 11) in Ni (sl. 12) v povr- šinski vodi niso presegale zakonodajnih smernic, izmerjeni vrednosti na posameznem vzorčnem mestu sta si v obeh opazovanih letih večinoma zelo podobni. Prostorska porazdelitev vsebnosti posameznih elementov je podana v nadaljevanju. Vsebnosti Mo v površinski vodi so bile v obeh le- tih v pritokih Meže (z izjemo pritoka 2) in v zgor- njem toku Meže do naselja Žerjav (na lokacijah SS-26/3, SS-26/6 in SS-26/9), nekoliko manjše kot v pritoku 2 ter lokacijah v Meži dolvodno od Žerjava (SS-26/15, SS-26/20, SS-26/21 in SS- 26/22). Ob tem so bile vsebnosti na vzorčnih mes- tih dolvodno od Žerjava leta 2020 izrazito večje, kot leta 2017. Vsebnosti As v površinski vodi so bile nekoliko večje v pritoku 2 in na vseh lokaci- jah v Meži (z izjemo lokacije SS-26/9), predvsem leta 2020. Vsebnosti Ba so nekoliko večje v Jaz- binskem (SS-26/10) in Junčarjevem potoku (SS- 26/19) ter v Meži na lokacijah SS-26/15, SS-26/20, SS-26/21 in SS-26/22. Nakazuje se, da vsebnosti Ba naraščajo navzdol po toku Meže. Vsebnosti Co so nekoliko večje v Helenskem potoku in pritoku 2 ter v Meži na lokacijah SS-26/15, SS-26/20 in SS-26/21. Vsebnosti Cu v površinski vodi so bile leta 2017 na vzorčnih mestih SS-26/5 in v Meži dolvodno od Žerjava izrazito večje, kot leta 2020. Tudi leta 2020 so bile vsebnosti v Meži nižje od Žerjava nekoliko večje od preostalih. Vsebnosti Ni so bile v obeh letih največje na vzorčnih mestih v Meži dolvodno od Žerjava, v posameznih pritokih pa se obe vsebnosti precej razlikujeta. Leta 2017 je bila izmed pritokov največja na vzorčnem mestu SS-26/8 in SS-26/11, leta 2020 pa na SS-26/11 in SS-26/19. Izkazalo se je, da so površinske vode reke Meže s pritoki manj obremenjene s PSE v raztopljeni in bolj s PSE v trdni obliki. Ugotovili smo le lokal- no velike vsebnosti v vodi, predvsem v vodotokih, ki odvodnjavajo odlagališča. To so koncentracije Pb v Helenskem potoku, pritoku 2, ki odvodnja- va Kavšakovo odlagališče in Junčarjevem potoku, koncentracije Zn v pritoku 2 in koncentracije Cd v pritoku 2. V Meži pa je površinska voda obre- menjena s Cd na lokacijah SS-26/15, SS-26/20, SS-26/21, to je nižje od Žerjava, v Mežici in dol- vodno od Mežice. Miler in sodelavci (2022) so s pomočjo izluževalnih testov (z vodo) ugotovili, da material iz odlagališč Štoparjev odval (Helenski potok), Igrče (Mušenik), Kavšakovo odlagališče (pritok 2, Jazbinski potok) in Fridrih (Junčarjev potok) vsebuje Pb, ki se lahko izlužuje in vpliva na vsebnosti Pb v vodni raztopini. Poleg tega se iz materiala odlagališč Fridrih in Kavšakovo odla- gališče izlužujeta tudi Cd oziroma Zn. To pomeni, da ima zadrževanje vode v odlagališčih pomembno vlogo pri dotoku raztopljenih oblik Pb, Zn in Cd v pritoke Meže. Z uporabo SEM/EDS mikroskopije v kombinaciji s PHREEQC simulacijami (Miler in sodelavci, 2022) je bilo ugotovljeno tudi, da je ve- liko rudnih mineralov (Zn-karbonati in sulfidi), ki se pojavljajo v materialu odlagališč in sedimentih, korodiranih, kar kaže na raztapljanje mineralov in sproščanje PSE v okolje pod pogoji, ki trenutno vladajo v površinskih vodah. V sedimentih in od- lagališčih se pojavljajo tudi sekundarni produkti preperevanja rudnih mineralov s PSE, med kate- rimi so pri danih pogojih v vodah Fe-oksihidroksi sulfati nestabilni, Fe-oksihidroksidi pa večinoma stabilni. Pri spremembi teh pogojev pa lahko hit- ro postanejo nestabilni, pri čemer se PSE sprostijo nazaj v vodno raztopino. Zaključek Z zaprtjem rudnika in predelovalno-metalur- ških obratov na območju Mežice, se je neposreden vnos PSE v okolje močno zmanjšal. Še vedno pa na okolje vplivajo stara bremena in sedanje antro- pogene dejavnosti. Kot posreden vir potencialno strupenih elementov (PSE) so ostala odlagališča rudarskih odpadkov (siromašne rude in odpadkov nastalih pri predelavi rude), iz katerih se PSE spi- rajo v bližnje potoke ter z njimi potujejo v Mežo ter dalje v Dravo. Na vsebnosti PSE v sedimentih 60 Mateja GOSAR, Špela BAVEC, Miloš MILER & Martin GABERŠEK vplivajo poleg odlagališč rudarskih odpadkov tudi vsesplošno obremenjeno naravno in urbano okolje. Iz vseh segmentov s kovinami obremenjenega oko- lja se izpira material v vodotoke. V obravnavanih sedimentih so vsebnosti PSE, predvsem Pb, Zn, Cd, Mo in As močno nad nivo- jem ozadja in večkratno presegajo kritično vred- nost za tla. Njihove vsebnosti močno nihajo med posameznimi vzorčnimi mesti in tudi med posa- meznimi leti (2013, 2017, 2020) na istih vzorčnih mestih. Nihanja med opazovanimi leti so najbolj izrazita v pritokih reke Meže, kjer se vsebnosti za- radi povečane erozije in transporta materiala kot posledica višjega vodostaja in pretoka, znatno po- povečajo. Vsebnosti v površinski vodi se bistveno ne spreminjajo. Pojavljajo se le zmerna povečanja Pb, Zn in Cd v vodi, ki so lokalnega značaja. Na podlagi rezultatov ugotavljamo, da so sedi- menti v dolini Meže še vedno močno obremenjeni s PSE. Zaradi erozijskih procesov na odlagališčih rudarskih odpadkov so ta pomemben vir materiala bogatega s PSE, ki se spira v vodotoke, ki jih od- vodnjavajo. Zato je potrebna njihova sanacija in še nadaljnje spremljanje stanja odlagališč in nivojev PSE v sedimentih in vodah. Zahvala Raziskave smo izvedli s f inančno podporo Ministrst- va za okolje in prostor v okviru projekta »Spremljanje zaprtih objektov za ravnanje z odpadki iz rudarskih in drugih dejavnosti izkoriščanja mineralnih surovin (2020 – 2021) (št. pogodbe 2550 – 20 – 340122)«, ki je bil izveden na Geološkem zavodu Slovenije. Raziska- va je bila delno financirana s strani Javne agencije za znanstvenoraziskovalno in inovacijsko dejavnost Re- publike Slovenije (ARIS) preko raziskovalnih pro- gramov »Podzemna voda in geokemija (P1-0020)« in »Mineralne surovine (P1-0025)«, ter raziskovalnega projekta »Dinamika in snovni tok potencialno strupenih elementov (PSE) v urbanem okolju (J1-1713)«. Finančno pomoč je nudila tudi Slovenska nacionalna komisija za UNESCO, Nacionalni odbor Mednarodnega programa za geoznanost in geoparke. Literatura ARSO 2023: Nalivi in obilne padavine od 3. do 6. avgusta 2023. Preliminarno poročilo. 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CC Atribution 4.0 License Palaeoecological significance of the trace fossil Circulichnis Vyalov, 1971 from the Carboniferous of the Donets Basin, Ukraine Paleoekološki pomen fosilne sledi Circulichnis Vyalov, 1971 iz karbona Doneškega bazena v Ukrajini Vitaly DERNOV Institute of Geological Sciences, National Academy of Sciences of Ukraine, 55 b, Oles Honchar Str., Kyiv, 01054, Ukraine, e-mail: vitalydernov@gmail.com Prejeto / Received 24. 2. 2023; Sprejeto / Accepted 15. 4. 2024; Objavljeno na spletu / Published online 11. 6. 2024 Key words: trace fossils, Circulichnis, Pennsylvanian, Ukraine Ključne besede: fosilne sledi, Circulichnis, pennsylvanij, Ukrajina Abstract The ichnogenus Circulichnis Vyalov is a horizontal a ring- or ellipse-shaped burrow and/or locomotion trace of an unknown producer, most likely an annelid or a “worm”, preserved on the bedding plane. This ichnogenus is known over a wide age interval (Ediacaran–Oligocene). Circulichnis demonstrates a wide ecological range and has been found in continental (Mermia ichnofacies), shelf, and relatively deep-water (turbidites) deposits. It is commonly interpreted as a sediment feeding trace, but the peculiarities of its formation remain somewhat mysterious, as it is unclear how the tracemaker reached the sediment surface, as lateral branches of the ring-shaped traces are extremely rare and have only been observed by a few researchers. A rather large specimen of Circulichnis montanus Vyalov, 1971 with a preserved lateral branch was found in the Mospyne Formation (upper Bashkirian, Lower Pennsylvanian) of the Donets Basin. This discovery confirmed the assumption made by Alfred Uchman and Bruno Ratazzi regarding the peculiarities of formation of Circulichnis. According to these authors, a single ring-shaped Circulichnis indicates an attempt to forage at a specific level in the sediment, while the lateral branches of Circulichnis are part of a vertical shaft leading to another level within the sediment. The study of Circulichnis montanus from the Donets Basin has confirmed that at least variant C of the Circulichnis formation scheme proposed by Uchman and Ratazzi is correct, i.e. the lateral branch is a horizontal or subhorizontal part of a generally vertical shaft. However, it is important to note that the correctness of variants A and B of the Uchman and Ratazzi scheme cannot be excluded. To answer this question unequivocally, new finds of well-preserved Circulichnis are necessary. Izvleček Ihnofosilni rod Circulichnis Vyalov, 1971 je vodoravna, obročasto ali elipsasto oblikovana sled vrtanja in/ali premikanja neznanih organizmov, najverjetneje anelidov ali “črvov”, ki so se ohranili na površini plasti. Ta ihnofosilni rod je poznan v širokem starostnem intervalu (ediakarij–oligocen). Circulichnis izkazuje širok ekološki razpon in je bil najden v kontinentalnih (Mermia ihnofacies), šelfnih in razmeroma globokomorskih (turbiditnih) sedimentih. Običajno ga tolmačijo kot sled prehranjevanja s sedimentom, vendar posebnosti njegovega nastanka ostajajo nekoliko skrivnostne, saj ni jasno, kako je organizem, ki je pustil sled, dosegel površino sedimenta, saj so stranske veje obročastih sledi izjemno redke in jih je opazilo le nekaj raziskovalcev. V formaciji Mospyne (zgornji baškirij, spodnji pennsilvanij) v Doneškem bazenu je bil najden precej velik primerek vrste Circulichnis montanus Vyalov, 1971. Na tem primerku je ohranjena stranska veja, kar je, kot je navedeno zgoraj, precej redko. To odkritje je potrdilo domnevo Alfreda Uchmana in Bruna Ratazzija o posebnostih nastanka rodu Circulichnis. Po tej domnevi je posamezen obroč Circulichnis poskus prehranjevanja na določeni ravni v sedimentu, medtem ko so stranske veje Circulichnis del vertikalnega rova, ki vodi na drugo raven v sedimentu. Raziskava Circulichnis montanus iz Doneškega bazena je pokazala, da je pravilna vsaj varianta C sheme nastanka rodu Circulichnis, ki sta jo predlagala Uchman in Ratazzi, tj. stranska veja je horizontalni ali subhorizontalni del sicer vertikalnega rova. Vendar to ne izključuje pravilnosti variant A in B Uchmanove in Ratazzijeve sheme. Nedvoumen odgovor na to vprašanje bodo lahko dale le nove najdbe dobro ohranjenih primerkov rodu Circulichnis. GEOLOGIJA 67/1, 63-70, Ljubljana 2024 https://doi.org/10.5474/geologija.2024.004 64 Vitaly DERNOV Introduction Circulichnis Vyalov, 1971 is a burrow or trail of enigmatic producers, most likely annelids or “worms”, in the form of a ring or ellipse pre- served on bedding surfaces (Pickerill & Keppie, 1981; Pickerill et al., 1988; Blissett & Pickerill, 2004; Uchman & Rattazzi, 2018). This ichnogenus ranged from the Ediacaran to the Oligocene (Uch- man & Rattazzi, 2018; Mor gan et al., 2023). Cir- culichnis shows a wide environmental range, from continental (Mermia ichnofacies) via shelf to deep- sea (turbiditic) deposits (e.g., Pickerill & Keppie, 1981; Fillion & Pickerill, 1984; McCann & Picker- ill, 1988; Buatois & Mángano, 1993; Buatois et al., 1998a). Circulichnis is generally considered to be a fodinichnion (Pickerill & Keppie, 1981; Mángano et al., 1997; Buatois et al., 1998a, b; Buatois et al., 2006). Carboniferous trace fossils from the Donets Basin have not yet been studied sufficiently. How- ever, they are of great palaeoecological impor- tance, since the Carboniferous carbonate platform (Tournaisian–Viséan (part)), paralic coal-bearing (Serpukhovian–Kasimovian (part)), and continen- tal red-bed (Kasimovian (part)–Gzhelian) strata in the Donets Basin were formed under different depositional conditions, from relatively deep-wa- ter shelf areas to lowland land, located in humid and arid climates (Logvinenko, 1953; Feofilova & Levenshtein, 1963; Novik, 1974; Kozitskaya & Fig. 1. Geographical location of the fossil site with Circulichnis montanus Vyalov, 1971. Abbreviation: V. Kamianka – Velyka Kamianka River. Geological map in Fig. 1B modified after Fissunenko (2004). 65Palaeoecological significance of the trace fossil Circulichnis Vyalov, 1971 from the Carboniferous of the Donets Basin, Ukraine Schegolev, 1993). As a result, they characterised different habitat conditions for animals and plants. This paper describes the ichnospecies Circu- lichnis montanus Vyalov, 1971 from the upper Bashkirian (Pennsylvanian) Mospyne Formation of the Donets Basin (Ukraine), which is important for clarifying the ethology of its tracemakers. In Ukraine, the trace fossils Circulichnis have been recorded in the Ediacaran deposits of Podillia (Gu- reev, 1983), in the Triassic and Jurassic deposits of Crimea (Dmitrieva et al., 1963; Shalimov, 1978) and in the sandstone bed below the G1 2 limestone layer of the Mospyne Formation in the study area (author’s unpublished data), i.e. about 300 m be- low the sandstone bed from which the trace fossil described here originates. Therefore, this study is also a documentation of the new record of Circu- lichnis in Ukraine. Geological setting and material Bashkirian-aged coal-bearing deposits in the Donets Basin were accumulated mainly in a large alluvial-deltaic plain, which was f looded periodi- cally by the epicontinental seas. Only the central part of the Donets Basin was characterized by a continuous regime of marine sedimentation in the Bashkirian. The sandstone bed with Circulichnis mon- tanus Vyalov, 1971 lies in the upper part of the Mospyne Formation (Fig. 2A, B), which is a 315 to 730 m-thick sequence of mudstone, silt- stone, sandstone, limestone, and coal (Feofilova & Levenstein, 1963; Dunaeva, 1969; Aisenverg et al., 1975; Poletaev et al., 2011; Nemyrovska & Yefimenko, 2013). These rocks were deposited in shallow marine, lagoonal, lacustrine, prodelta- ic, deltaic, peat and clastic swamp environments (Logvinenko, 1953; Feofilova & Levenshtein, 1963). The Mospyne Formation corresponds to the lower part of the Zuyivkian Horizon (lower half of the Kayalian Regional Stage) of the Re- gional Stratigraphic Scheme of the Dnipro-Do- nets Downwarp (Poletaev et al., 2011; Nemyrovs- ka & Yefimenko, 2013). This formation contains remains of typical Langsettian terrestrial plants (Novik, 1974; Dernov & Udovychenko, 2019a) and Fig. 2. Stratigraphic position (A, B) and the general view of the Circulichnis-bearing fossil site (C). 66 Vitaly DERNOV ammonoids (Popov, 1979; Dernov, 2022b), the non-marine bivalves of the upper part of the leni- sulcata Zone and the lower part of the communis Zone (Dernov, 2022a), the late Bashkirian cono- donts (Nemyrovska, 1999), and other marine and terrestrial biota, such as miospores, foraminifers, corals, bryozoans, brachiopods, scaphopods, gas- tropods, horseshoe crabs, millipedes, insects and fishes. Some trace fossils from the Mospyne Forma- tion, such as the ichnospecies of the ichnogenera Arborichnus, Arenicolites, Avetoichnus, Archae- onassa, Aulichnites, Bergaueria, Chondrites, Co- chlichnus, Conichnus, Cyclopuncta, Diplichnites, Diplocraterion, Diplopodichnus, Gordia, ?Halopoa, Helminthopsis, Kouphichnium, Lockeia, ?Lophoctenium, Mammillichnis, Monocraterion, Monomorphichnus, Paleophycus, Phycodes, Phy- cosiphon, Planolites, Ptychoplasma, Protovirgu- laria, Rhizocorallium, Rogerella, Rusophycos, Saerichnites, Scolithos, Selenichnites, Treptichnus and evidences of arthropod-plant interaction have been previously described or figured by the author (Dernov, 2019a, b; Dernov & Udovychenko, 2019b; Dernov, 2021, 2022c, 2023). The studied specimen GMLNU-15/01 is a sin- gle trace fossil Circulichnis montanus Vyalov, 1971 on a slab of fine-grained, polymictic, horizontal- ly-bedded, grey sandstone. It was collected by the author from the sandstone bed in the upper part of the Mospyne Formation. This sandstone bed is ex- posed in the Dubova Ravine, located 2 km west of the village of Kamianka (Ukraine, Luhansk Region: 48°14’54.8”N 39°20’48.0”E; Fig. 1). The section is poorly exposed here (Fig. 2C), but in the neigh- bouring Sukha Ravine and near the village of Make- donivka, it has been exposed in small quarries. No Circulichnis has been found at these other sites, but numerous other trace fossils, such as Archaeonassa, Aulichnites, Bergaueria, Planolites, and Treptichnus are present. The specimen GMLNU-15/01 is housed in the Geological Museum of the Luhansk Taras Shevchenko National University (Poltava, Ukraine). Systematic ichnology Ichnogenus Circulichnis Vyalov, 1971 Type ichnospecies: Circulichnis montanus Vyalov, 1971; by original designation. Diagnosis: Horizontal, approximately circular to oval, cylindrical ring (after Uchman & Rattazzi, 2018). Remarks: Keighley & Pickerill (1998) proposed to change the spelling of the ichnogenus from Cir- culichnis to Circulichnus, arguing that in the origi- nal description of this ichnotaxon by Vyalov (1971), there was a mistake in the spelling of its ending. I see no reason for such a decision, because nowhere is it officially stated that the names of ichnogenera should end in -ichnus. Moreover, in the text of the work of Vyalov (1971), the spelling Circulichnis is used everywhere, so the ending -ichnis cannot be a typographical error. This opinion is shared by many other researchers (for example, Uchman & Rattazzi, 2018; Morgan et al., 2023). Occurrence: Ediacaran–Oligocene (Palaeo- gene); worldwide distribution. Circulichnis montanus Vyalov, 1971 Fig. 3 (See Uchman & Rattazzi (2018, pp. 4, 5) for synonymy) Material: One well-preserved specimen (GML- NU-15/01). Description: Horizontal, smooth, unlined, ring- shaped and subcylindrical burrow, 10 to 15 mm wide and 12.5 cm and 10.0 cm in external diam- eters, preserved as a concave epirelief on the up- per bedding plane. The width of the burrow varies considerably, which may be a taphonomic artefact caused by the fact that it is exposed to different depths. A much narrower, slightly curved burrow, about 50 mm long and 8–9 mm wide, extends from the ring at an acute angle. The burrow fill is identical to the host rock. Remarks: In addition to the type species, sev- eral ichnospecies have been described under the name Circulichnis/Circulichnus, such as Circu- lichnus ngariensis Yang & Song, 1985, Circulichnis spiralis Li, 1993, and Circulichnis sinensis Yang, 1990, but they are not related to Circulichnis or are synonymous with Circulichnis montanus (Uch- man & Rattazzi 2018). However, Fan et al. (2021) have reviewed C. sinensis as a valid ichnospecies, despite the fact that this ichnospecies, as well as Circulichnis leomonti Morgan, Juntunen, Scott & Landreth, 2023, differs from Circulichnis monta- nus in its segmental structure. Circulichnis mon- tanus described above differs from Circulichnis ligusticus Uchman & Rattazzi, 2018 by the regular elliptical course of the burrow. The specimen GMLNU-15/01 differs somewhat from the holotype of Circulichnis montanus f ig- ured by Vyalov (1971, pl. 1, f ig. 1) and Uchman & Rattazzi (2018, fig. 2), namely: (1) the holotype is much smaller (the large diameter is about three times smaller than that of the specimen GML- NU-15/01; (2) the holotype is represented by a convex hyporelief, whereas the specimen GML- NU-15/01 is preserved as a concave epirelief; (3) 67Palaeoecological significance of the trace fossil Circulichnis Vyalov, 1971 from the Carboniferous of the Donets Basin, Ukraine the holotype is composed by a cylindrical annu- lar ridge, whereas the specimen GMLNU-15/01 is either a partially destroyed cylindrical or subcy- lindrical burrow. However, the morphology of the specimen GMLNU-15/01 does not contradict the diagnosis of Circulichnis montanus given in the re- vision by Uchman & Rattazzi (2018, p. 5), name- ly: “horizontal, cylindrical burrow, which shows a course along a regular circle or ellipse”. The speci- men GMLNU-15/01 is much larger than the holo- type of Circulichnis montanus, but the size is not of ichnotaxonomic significance (Pickerill, 1994). From the Cretaceous deposits of Alaska, McCann & Pickerill (1988) described specimens of Circu- lichnis montanus similar in size to Circulichnis montanus described above. Locality: Ukraine, Luhansk Region, left slope of the Dubova Ravine, 2 km west of the village of Kamianka; upper part of the Mospyne Formation (late Bashkirian, Early Pennsylvanian). Fig. 3. Circulichnis montanus Vyalov, 1971 from the Mospyne For- mation of the Donets Basin (specimen GMLNU-15/01). Scale bar = 10 mm. Discussion and concluding remarks Vyalov (1971) and Keighley & Pickerill (1998) suggested that Circulichnis could not be un- branched, as its tracemaker could not have ap- peared from nowhere and had to somehow got to the area of the seabed where it subsequently formed the trace. Probably, in most cases, the in- coming (and outgoing) branch could not be pre- served, since, for example, it could be located in a different plane relative to the main part of the trace (Vyalov, 1971; Pickerill & Keppie, 1981). Pickerill & Keppie (1981), suggested that Cir- culichnis and Helminthopsis from the Cambri- an–Ordovician deposits of Nova Scotia (Canada) were produced by the same producers, most likely annelid worms. This conclusion was supported by the fact that these traces occur on the same bed- ding surfaces and sometimes overlap (Häntzschel, 1975, fig. 2a on p. W71; Pickerill & Keppie, 1981, f ig. 3c). Uchman & Rattazzi (2018) proposed a mod- el for the function of Circulichnis, according to which, Helminthoidichnites, Gordia, and Hel- minthopsis are burrows or trails used for feeding, locomotion, or both. The trace makers probably used these structures to explore the environment at different sediment depths, primarily for feed- ing, and often along bedding interfaces. According to this model, the rejoining of the shaft can occur at the point where the vertical to subvertical shaft connects with the ring, or with the shaft bent to a horizontal position near the ring, or with the shaft diverging in the lower part and transitioning to an imperfect ring that is not closed on the same level. However, a vertical or subvertical shaft hypo- thetically connecting Circulichnis to another level within the sediment has never been observed, but only documented cases of a horizontal short branch of the Circulichnis ring (Uchman & Rattazzi, 2018), as in the specimen GMLNU-15/01. The lateral branch of the specimen GMLNU-15/01, if found in isolation from the ring, could be assigned to the ichnogenus Planolites or Palaeophycus, so there is good reason to believe that the producers of these ichnogenus, as well as Helminthoidich- nites, Gordia, and Helminthopsis, could also pro- duced Circulichnis. The studied material suggests that at least the variant of the Circulichnis ethological model pro- posed by Uchman & Rattazzi (2018, fig. 6A, B – variant C; see fig. 4) is correct. However, it is not yetclear whether it is the only possible one. Fig. 4. Model of Circulichnis. Modified from Uchman & Rattazzi (2018, fig. 6). 68 Vitaly DERNOV Acknowledgements I would like to thank the anonymous reviewers whose comments and suggestions improved the quality of the f inal version of the manuscript. 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CC Atribution 4.0 License Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia Srednjetriasna globljemorska vulkansko-sedimentna zaporedja v zahodni Sloveniji Dragomir SKABERNE1,2, Jože ČAR3,4, Maja PRISTAVEC3,5, Boštjan ROŽIČ3 & Luka GALE2,3,* 1Medvedova c. 10, SI–1000 Ljubljana, Slovenia; e-mail: dskaberne@gmail.com 2Geological Survey of Slovenia, Dimičeva ulica 14, SI–1000 Ljubljana, Slovenia; *corresponding author: luka.gale@geo-zs.si 3Department of Geology, Faculty of Natural Sciences and Engineering, University of Ljubljana, Aškerčeva cesta 12, SI–1000 Ljubljana, Slovenia; e-mail: bostjan.rozic@ntf.uni-lj.si; luka.gale@ntf.uni-lj.si 4Finžgarjeva ulica 18, SI–5280 Idrija, Slovenia; e-mail: joze.car@siol.net 5Brnica 58, SI–1430 Hrastnik, Slovenia; e-mail: maja.pristavec@gmail.com Prejeto / Received 12. 2. 2024; Sprejeto / Accepted 7. 5. 2024; Objavljeno na spletu / Published online 11. 6. 2024 Key words: stratigraphy, carbonate-siliciclastic deposits, Slovenian Basin, Middle Triassic, Ladinian, Carnian, Pseudozilja formation, Amphiclina formation Ključne besede: stratigrafija, karbonatno-siliciklastični sediment, Slovenski bazen, srednji trias, ladinij, karnij, psevdoziljska formacija, amfiklinska formacija Abstract A Ladinian – Carnian volcano-sedimentary succession from western Slovenia, paleogeographically belonging to the western Slovenian Basin, is presented in 17 sections. Except for the lowermost part, which is dominated by volcanics and volcaniclastics, most of the succession is dominated by shale, sandstone, and micritic limestone. Various authors use the name Pseudozilja and/or Amphiclina formation for this part, which is dominated by clastics, but they disagree on the differences between the formations. The lower Pseudozilja formation, represented by the Malenski Vrh section, comprises diabase, tuf and shale. No substantial differences in lithological composition have been observed between the upper Pseudozilja formation and the Amphiclina formation, which are predominantly composed of shale, sandstone, and limestone. The shale and sandstone are largely composed of quartz, feldspar, and lithic grains (especially volcanics), which vary in proportions. Limestone varieties comprise hemipelagic limestones and resedimented carbonates deposited by gravity-f lows. Deposition of the Ladinian – Carnian volcano-sedimentary succession took place on or near the continental slope that was generally inclined to the S, with the direction of transport mainly from N to S. Izvleček V članku v 17 profilih predstavljamo ladinijsko – karnijsko vulkansko-sedimentno zaporedje zahodne Slovenije, paleogeografsko umeščeno v zahodni del Slovenskega bazena. Spodnji del psevdoziljske formacije, posnet na Melenskem vrhu, sestavljajo diabaz, tuf in laminiran muljevec. Zgornji del psevdoziljske formacije in amfiklinska formacija sta litološko identična. V večjem delu ju sestavljajo laminiran muljevec, peščenjak in apnenec. Glavne sestavine muljevca in peščenjaka so kremen, glinenci in litična zrna (predvsem predornin) v različnih razmerjih. Apnenec obsega hemipelagični apnenec in resedimentirane karbonate. Sedimentacija ladinijsko – karnijskega vulkansko-sedimentnega zaporedja je potekala na ali v bližini kontinentalnega pobočja z nagibom proti jugu. Transport sedimenta je v glavnem potekal od severa proti jugu. GEOLOGIJA 67/1, 71-103, Ljubljana 2024 https://doi.org/10.5474/geologija.2024.005 (rhyolite, diabase, and basalt), tuffs, volcaniclastic sandstone, feldspar-quartz-lithic sandstone and shale with intercalations of conglomerate, mud- dy conglomerate and breccia, bedded hemipelagic limestone, and carbonate olistoliths (bioherms?) (Stur, 1858; Teller, 1885, 1889; Kossmat, 1901, 1910, 1913; Winkler, 1936; Rakovec, 1950; Ram- ovš, 1970; Grad & Ferjančič, 1976; Placer & Čar, 1977; Čar et al., 1981; Turnšek et al., 1982; Bus- er, 1986; Šmuc & Čar, 2002; Dozet & Buser, 2009; Introduction The time range and paleogeographic extent of the Slovenian Basin, a deeper marine sedimenta- ry basin situated on the western Tethyan margin, is based on a succession of open-marine Mesozoic rocks, which today are exposed between Tolmin in western Slovenia and Neogene sediments of the Central Paratethys in eastern Slovenia (Buser, 1989, 1996; Buser et al., 2008). The lowermost/ oldest rocks of the Slovenian Basin are volcanics 72 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE Demšar, 2016; Gale et al., 2016; Čar et al., 2021). While some authors (e.g. Turnšek et al., 1982; Buser, 1986) distinguished between the Ladinian (informal) Pseudozilja (also Pseudozilian, Pseu- dogailtal) formation and the Carnian Amphiclina formation based on the presence or, respectively, absence of volcaniclastics, others argue that the entire succession should be treated as one, that is, as the Pseudozilja formation (e.g., Čar et al., 1981, 2021). We note here that although neither name follows modern stratigraphic standards, the In- ternational Stratigraphic Guide states that “tradi- tional or well-established names /…/ should not be abandoned, providing they are or may become well defined or characterized” (Murphy & Salvador, 19.06.2023). The lower part of the volcano-sedi- mentary succession is relatively poorly dated. The succession rests unconformably on Lower Trias- sic shallow-water deposits or, more commonly, its base is tectonically cut-off. Rare fossil f inds (bi- valves) from tuff beds suggest that deeper-water sedimentation in the Slovenian Basin started in the Ladinian (Teller, 1889; Jurkovšek, 1984; Bus- er, 1986). However, the deepening could already have begun in the late Anisian during the regional extension of the crust and the formation of horst- and-graben relief (e.g. Buser, 1989; Gianolla et al., 1998a; Celarc et al., 2013; Smirčić et al., 2020). The uppermost part of the investigated suc- cession is represented by interchanging beds of dark limestone and shale dated with conodonts as late Carnian (Tuvalian) in age (Buser & Kriv- ic, 1979; Kolar-Jurkovšek, 1982, 1990; Demšar, 2016). After a few meters, this transitional inter- val gives way to bedded dolostone with chert nod- ules known as the (also informal) Bača dolomite (i.e. dolostone) formation (Kossmat, 1901; Buser, 1986; Gale, 2010). In the more proximal settings, earlier (i.e. late Ladinian or early Carnian) transi- tion to platform carbonates has been recorded (Čar et al., 2021). With a combined thickness of 600 m (estima- tion based on profiles on geological maps; Buser, 1986; Demšar, 2016), the Pseudozilian/Amphiclina formations represent a notable zone of rheological weakness, along which important thrusting took place during the formation of the Alps (Placer & Čar, 1998; Placer, 1999; Placer et al., 2000). From the stratigraphic point of view, this succession is a sedimentary record of the early evolution of the Slovenian Basin, bearing information about the paleogeography, paleoclimate, and oceanograph- ic conditions in this part of the Tethys during the Ladinian and Carnian. Due to the absence of data on the biostratigraphic and radiometric age, the lack of known and described sedimentary sections as well as abrupt lateral and vertical changes in lithologies, however, we have yet to find the key to access such information. The purpose of the present paper is to show the lithological composition of the volcano-sedimen- tary succession lying below the Bača dolomite for- mation. Some of the sections end with the transi- tion to the Bača dolomite formation and thus have a well-known stratigraphic position. For others, we have no biostratigraphic or other data to de- termine the age; these were stratigraphically posi- tioned based on the geological map (Buser, 1987; Demšar, 2016). Methods The Middle – lower Upper Triassic volcano-sed- imentary succession of the Slovenian Basin was logged in 17 sections from 13 localities. Sections were logged between the years 1982 and 1990 by authors D.S. and J.Č. at scales of 1:50, 1:100 and 1:500. Approximately 270 thin sections were made for more detailed investigation under a polarizing petrographic microscope. Carbonates were clas- sified according to Dunham (1962), modified by Wright (1992), and Lokier and Junaibi (2016). The terminology of the volcanically derived deposits follows Di Capua et al. (2022). In addition to thin section analysis, 38 samples of fine-grained clas- tic rocks were investigated using a Philips X-Ray Diffractometer with vertical goniometer and mon- ochromator with a Cu cathode, Cuαk-0,1542 nm, powered up to 40 kW and 20 mA. Structural setting and stratigraphic position of the sections The logged sections lie between Železniki in the east, Koritnica in the west, and Cerkno in the south (Figs. 1–2; Table 1). In addition, Figure 1 also shows the positions of previously documented sections at Vrh Bače (Gale, unpubl. 2012), Crngrob (Gale et al., 2017), and Martinj Vrh (Pristavec et al., 2021). Except for the Malenski vrh section, which structurally lies in the Trnovo Nappe that belongs to the External Dinarides, all the other presented sections belong to the Tolmin Nappe of the eastern Southern Alps, more precisely to the Podmelec subnappe (Table 1). The Vrh Bače, Crn- grob, and Malenski Vrh sections are structurally positioned in higher Kobla and Rut subnappes of the Tolmin Nappe, respectively. Both the External Dinarides and the Tolmin Nappe of the Southern Alps are marked by the NE to SW thrusting that took part approximately from the Oligocene to the early Miocene (Vrabec 73Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia & Fodor, 2006). Later in the Miocene, the area of the Southern Alps experienced N-S to SE-NW-di- rected compression, which additionally resulted in the formation of S- to SE-verging folds and thrusts (Vrabec & Fodor, 2006). On a more detailed level all of the mentioned nappes further contain in- ner thrust blocks and smaller inner thrust-sheets, particularly at the transition between the South- ern Alps and the Dinarides (Placer & Čar, 1998; Čar et al., 2021). Younger tectonic deformations of the area include local extension along NW-SE- trending normal faults that were reactivated as dextral strike-slip faults that today displace both sets of older folds and thrusts (Fig. 3) (Placer & Čar, 1998; Vrabec & Fodor, 2006). The stratigraphic position of the presented sec- tions is taken after Demšar (2016) and/or the lith- ological composition of the sections. According to Demšar (2016), the lower part of the Ladinian – lowermost Carnian Pseudozilja formation consists of volcanics laterally and vertically passing into shale and tuff. Bedded limestone is subordinate and intercalated among volcanics. The higher part of the Pseudozilja formation is represented by vol- canoclastic sandstone, shale, conglomerate, tuff, and subordinate bedded and massive limestone. The Carnian Amphiclina formation is defined by the same lithologies, except for the absence of tuff. In the upper part, the Amphiclina formation is mostly shale, sandstone, and quartz-carbonate lithic sandstone, with the addition of limestone, conglomerate, and breccia. The latter two locally contain abundant matrix. Nearing the transition into the Bača dolomite formation, the uppermost Amphiclina formation mostly comprises inter- changing beds of limestone and shale (Demšar, 2016). Fig. 1. Geographic position and structure of the studied area. a: Geotectonic units of central Slovenia, with present-day distribution of rocks deposited in the Slovenian Basin. Modified after Buser et al. (2007). b: Geographical position of the logged sections and the general structure of the studied area. Modified after Grad and Ferjančič (1974), Buser (1987), and Demšar (2016). Sections Martinj Vrh (1), Crngrob (2), and Vrh Bače (3) were previously investigated by Pristavec et al. (2021), Gale et al. (2017), and Gale (2012, unpubl.), respectively. 74 Fig. 2. Detailed position of the studied sections. a: Sections Novaki (NO 1–4), and Črni Vrh (ČV 3, ČV 4). b: Section Koritnica (KO). c: Sec- tions Davča (D1, D2). d: Section Malenski Vrh (MV). e: Sections Hudajužna (HJ), Zakojca (ZK 1, ZK2, ZK 3), Jesenica (J1, J2), Orehek (OR), and Poče (PO). LIDAR digital model of the relief, 2015. Source: Slovenian Environment Agency. Accessed via portal Geopedia (Sinergise d.o.o.) in May 2023. For geographic coordinates see Table 1. Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE 75Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia Description of sections Descriptions of logged successions are ordered according to their stratigraphic position (Table 1), starting with the lower part of the Pseudozilja for- mation and ending with the uppermost part of the Amphiclina formation sensu Demšar (2016). The stratigraphic position of the sections Jesenica 1 and 2 is ambiguous; they could represent either the upper part of the Pseudozilja formation or the lower part of the Amphiclina formation. Most of the sedimentary rocks of the Pseudozilja/Amph- iclina formation are medium to dark grey, nearly black, so their colour will not be recorded in the subsequent description of the logged sections. The general aspect of the Pseudozilja/Amphiclina for- mations is shown in Figure 4. Fig. 3. Example of the minor thrust-sheet near Črni Vrh (coloured green) that is positioned just above the main South-Alpine Thrust Fault and characterized by partly overturned beds (for abbreviations of logged sections see Fig. 1). Note that in older publications (e.g., Placer & Čar, 1998; Placer, 1999, 2008) the structural unit marked here as the Trnovo Nappe was considered a thrust-sheet within the Hrušica Nappe. Section Stratigraphic position Start of section End of section Structural position Malenski Vrh Lower & upper Pseudozilja fm. 46o9’18.41’’N, 14o8’30.84‘‘E 46o9’23.54’’N, 14o8‘58.73‘‘E External Dinarides (Malenski vrh klippe) Črni Vrh 3 (in inverse position) Upper Pseudozilja fm. 46o9’43.86’’N, 14o3‘47.80‘‘E 46o9’46.22’’N, 14o3‘51.12‘‘E Črni Vrh 4 (in inverse position) Upper Pseudozilja fm. 46o9’43.86’’N, 14o3‘47.80‘‘E 46o9’46.22’’N, 14o3‘51.12‘‘E Jesenica 1 Upper Pseudozilja/lower Amphiclina fm. 46o9’14.49’’N, 13o56‘58.45‘‘E 46o9’10.96’’N, 13o57‘2.76‘‘E Jesenica 2 Upper Pseudozilja/lower Amphiclina fm. 46o9’8.57’’N, 13o57‘10.45‘‘E 46o9’3.30’’N, 13o56‘41.89‘‘E Novaki 1–4 Lower Amphiclina fm. 46 o9’40.65’’N, 14o2‘16.86‘‘E 46o9’56.28’’N, 14o2‘26.47‘‘E Davča 1–2 Upper Amphiclina fm. 46 o10’29.26’’N 13o59‘59.93‘‘E 46o10’19.30’’N 13o59‘47.62‘‘E Southern Alps, Tolmin Nappe, Podmelec subnappe Poče Upper Amphiclina fm. 46 o9’15.12’’N, 13o59‘13.77‘‘ E 46o9’21.29’’N, 13o59‘7.99‘‘E Zakojca 1 Upper Amphiclina Fm. 46 o9’37.56’’N, 13o56‘59.27‘‘E 46o9´39.06’’N, 13o56‘53.37‘‘E Zakojca 2 Upper Amphiclina Fm. 46 o9’39.24’’N, 13o56044.74‘‘E 46o9’43.66’’N, 13o56‘46.52‘‘E Orehek Upper Amphiclina fm. 46 o8’52.23’’N, 13o56‘19.35‘‘E 46o9’7.67’’N, 13o56‘7.68‘‘E Hudajužna Upper Amphiclina fm. 46 o10’5.57’’N, 13o54‘29.60‘‘E 46o10’6.79’’N, 13o54‘35.73‘‘E Koritnica (in inverse position) Upper Amphiclina fm. 46o11’43.41’’N, 13o53‘41.82‘‘E 46o11’36.44’’N, 13o53‘31.32‘‘E Table 1. Geographic coordi- nates, structural and strati- graphic position of the stud- ied sections (see text). 76 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE Pseudozilja formation (Malenski Vrh) The Malenski Vrh section includes the low- ermost part of the Pseudozilja formation and its clastics-dominated upper part. The entire volca- no-sedimentary succession on the western slope of Malenski Vrh unconformably overlies Lower Tri- assic oolitic limestone (Fig. 5; also see Skaberne & Čar, 1986). The lowermost part of the Pseudozilja formation consists of 25 m of diabase with vacu- oles filled by calcite and chlorite, followed by litho- clastic-crystalloclastic tuff with intercalations of diabase that is pyritized in places. The diabase and tuff unit is approximately 190 m thick and is 35 % covered. It is followed by a succession of siliciclas- tic and carbonate rocks 260 m thick. The lower part of this interval, approximately 170 m thick, is partly covered and shale dominated, with rare thin interlayers and lenses of sandstone and lime- stone (mostly wackestone, subordinate pack- and grainstone). Approximately 90 m from the start of the siliciclastic and carbonate unit, which is domi- nated by shale, a lens-shaped body of pebbly sand- Fig. 4. Lithofacies of the Ladinian – Carnian volcano-sedimentary succession of the Slovenian Basin (Pseudozilja and Amphiclina for- mations sensu Demšar, 2016). a: Limestone interbedded with shale. Davča 1, 0.2–1.2 m. b: Interchange of shale-dominated heterolithic intervals with conglomerate and sandstone beds. Davča 1, 18.5 m. c: Lenticular bedding and ripple marks; sandstone interbedded in shale. Davča 1, 24.0 m. d: Transition from uppermost Amphiclina formation (right side of the picture) to the Bača dolomite formation (left side of the picture). Davča 2, 14.5–17.0 m. e: Sindepositional fold (slump). Interchange of calcarenite and shale. Koritnica 1, 45–46.3 m. f: Blocky limestone conglomerate. Koritnica 1, 33.0 m. 77Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia stone is recorded. It is characterised by a sharp, erosive lower boundary, and reaches up to 7 m in thickness. The sandstone consists mostly of feld- spar, very altered volcanic lithic fragments, and quartz grains, with some chlorite and muscovite f loating in quartz-sericite matrix and corrosion calcite cement. Approximately 160 m thick suc- cession of shale follows. Locally, up to 25 m thick blocks of massive, in the lower part bedded lime- stone are present within the shale. No deforma- tions around the massive limestone bodies were observed. Shale consists of 28–41 % of quartz, 6–15 % of feldspar, 19–34 % of muscovite /illite, 17–37 % of chlorite, and 0–26 % of calcite. Upper Pseudozilja formation (Črni Vrh 3–4) The sections Črni Vrh 3–4 are in overturned position. They are structurally situated in the Črni Vrh internal thrust sheet, in the tectonic zone between the Southern Alps and the External Di- narides. Approximately 12 m of the Pseudozilja formation recorded in the Črni vrh 3 section rep- resent a fining-upward succession (Fig. 6). The lower part of the section displays normally graded sequences of conglomerate, upwards transitioning into coarse-grained sandstone with shale rip-up clasts. Conglomerates have erosive lower bedding planes. Pebbles in conglomerate are f lattened, partly imbricated, and largely represented by rhy- olites, felsic tuffs, and subordinate quartz grains. The last conglomerate bed overlies a 0.8 m bed of micritic limestone, laterally passing into shale. The top of the section is represented by sandstone, passing into shale. All coarser-grained beds are normally graded. The Črni Vrh 4 section was logged in an aban- doned quarry and stratigraphically lies above the Črni Vrh 3 section. The Črni Vrh 4 section com- prises 43.6 m of the upper Pseudozilja formation, principally sandstone and conglomerate, interca- lated with shale. Conglomerate mostly contains pebbles of rhyolites, felsic tuffs, subordinate quartz, and locally rip-up shale clasts. Several f ining- and thinning-upward conglomerate-sand- stone sequences can be recognized, each meas- uring 0.4–5 m in thickness. Sequences from the lower part of the section are thicker and are amal- gamated or with thin intervals of shale in places. The sequences from the upper part of the section are finer-grained and thinner. The fine-grained part of sequences mostly consists of heterolithic intervals with 60–70 % of the interval consisting of fine-grained sandstone and 30–40 % shale. Fig. 5. Sedimentary log of the Malenski Vrh section. The section was logged schematically. 78 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE Upper Pseudozilja formation and/or lower Am- phiclina formation (Jesenica 1–2) The Jesenica 1 section comprises 160 m of si- liciclastic rocks, which are 50 % covered (Fig. 7). Even so, a coarsening-upward trend can be detect- ed from the bottom to the top of the section. The lowermost 38 m of the section is shale-dominated. Approximately 15 % of this interval is represented by fine and very-fine sandstone that forms inter- changing beds and lenses 2–20 cm thick. Sand- stone is locally planar- and cross-laminated. After a 21 m thick gap, a 14.5 m thick heterolithic inter- val is exposed. Sandstone represents 30 % of the interval and is present in beds up to 10 cm thick. Small-scale slumps are present in the lower part of this interval. After another 13 m of covered inter- val, the next part of the section comprises a 13 m thick heterolithic interval, in which sandstone forms 50 % of the lithology, forming beds 5–40 cm thick. Lower bed boundaries are often erosional, and channelized, with scours running in a N–S direction. Load casts on lower bedding planes and ripple marks on upper bedding planes are com- mon. Sandstone beds often contain rip-up clasts of shale in their lowermost parts, and display nor- mal grading and planar and cross lamination in their upper parts. After another 19 m thick gap, a sandstone-dominated (60 %), interval 20 m thick follows. Sandstone beds are up to 50 cm thick and display the same characteristics as the underlying beds, with more pronounced cross lamination and ripple marks. Above a bed of normally graded peb- bly to fine-grained sandstone, another heterolith- ic interval 3.4 m thick that is dominated by shale follows. Up to 20 cm thick, often normally graded and/or planar-laminated or normally graded beds of sandstone represent 20 % of this interval. Up to 3 m thick, matrix-supported conglomerate follows, bearing up to 30 cm large clasts of sandstone. The conglomerate is overlain by a heterolithic inter- val 1.5 m thick, which is dominated by shale. The next 12 m thick part of the section is covered. Ma- trix-supported muddy conglomerate approx. 5 m thick with large sandstone clasts up to 50 cm, fol- lows. This is covered by a 5 m thick heterolithic, shale-dominated interval containing approx. 40 % of fine and very fine-grained sandstone. The Jesenica 2 section, which measures 56 m in thickness (Fig. 8) lies in a slightly higher strati- graphic position than the succession described in the Jesenica 1 section. The first 39.6 m of the suc- cession exhibits a coarsening-upward trend. This part is composed of heterolithic intervals compris- ing 60–90 % shale that is often bioturbated and in places contains calcite concretions and 10–40 % of sandstone in beds and lenses up to 10 cm thick. Shale-dominated heterolithic intervals from the upper half of the succession are interrupted by more sandy intervals, or by beds of conglomerate up to 60 cm thick, grading into sandstone showing planar and cross lamination. The conglomerate has erosive lower boundaries, with the proportion of coarser intervals increasing upwards. After a prominent bed of a matrix-supported conglomer- ate 5 m thick with sandstone and limestone clasts Fig. 6. Sedimentary log of the Črni Vrh sections. Right-side mark- ings delineate grain sizes: Cy- clay, Si- silt, vf- very fine sand, f- fine sand, m- medium sand, c- coarse sand, vc- very coarse sand, g- granule, p- pebble, co- cobble. 79Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia Fig. 7. Sedimentary log of the Jesenica 1 section. Right-side markings delineate grain sizes: Cy- clay, Si- silt, vf- very fine sand, f- fine sand, m- medium sand, c- coarse sand, vc- very coarse sand, g- granule, p- pebble. up to 20 cm large, a finning-upward succession of shale 16.4 m thick follows. Shale is bioturbated, interbedded by normally graded conglomerate and thin sandstone beds with load casts. A single bed of micritic limestone is present near the top of the section. Lower Amphiclina formation (Novaki 1–4) The Novaki 1 section comprises a succession 39.6 m thick dominated by coarse- to fine-grained siliciclastic rocks (Fig. 9). The 1.5 m thick hetero- lithic, shale-dominated interval contains thin beds 80 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE and lenses of limestone (mudstone). It is overlain by an 11 m thick coarse-grained interval compris- ing normally graded, amalgamated beds of con- glomerate and sandstone. The conglomerate beds contain mostly limestone pebbles and gradually pass to coarse-, medium- and fine-grained sand- stone. The interval is overlain by 5 m thick shale, followed by 22 m of shale-dominated succession. Shale interchanges with calcareous conglomerate and siliciclastic sandstone. Sandstone is normally graded, planar-, and cross-laminated. The Novaki 2 section reaches a thickness of 34 m (Fig. 9). It begins with a 10 m thick hetero- lithic interval consisting of shale and subordinate (25 %) beds of limestone (wackestone). A 4 m thick package of medium-grained massive sandstone follows, overlain by a 20 m thick succession com- prising several sedimentary sequences. The lower- most sequences begin with conglomerate, contain- ing mostly non-calcareous pebbles. Conglomerate gradually passes into sandstone. Other sequences begin with coarse- to medium-grained sandstone and are partly normally graded. Finer parts of the sequences mostly consist of heterolithic intervals in which shale prevails over thin sandstone beds. The Novaki 3 section comprises 20.5 m of mostly sandstone and subordinate darker shale (Fig. 9). They are subdivided into several sedimen- tary sequences of different thicknesses. Sequences begin mostly with an erosional surface, followed by medium- to very coarse-grained sandstone, which is pebbly in the upper part of the section. The sandstone beds are 0.5–2.5 m thick, normally graded, and in some beds planar-laminated in the upper parts. The upper, f ine-grained parts of the sequences are 1–1.8 m thick heterolithic intervals comprised of 60 % shale and 40 % sandstone in thin beds and lenses. The Novaki 4 section measures 22.5 m in thick- ness (Fig. 9). The lower 6 m are represented by in- terchanging thin beds of shale and 20–30 cm thick beds of normally graded fine-grained sandstone. The remaining 16.5 m of the section are subdivid- ed into 0.7–5.2 m thick sedimentary sequences. Sequences are dominated by sandstone and pebbly sandstone. Normally graded sandy conglomerate with erosional base is subordinate. Shale forms upper fine-grained parts 0.2–1 m thick of the se- quences. Upper Amphiclina formation (Davča 1–2, Poče, Zakojca 1–2, Orehek, Hudajužna, Koritnica) The described sections are ordered according to their geographic position from E to W. The Davča 1 section represents the upper 80 m of the Amphiclina formation (Fig. 10). The sec- tion starts with an 8.4 m thick fining-upward suc- cession, comprising sequences of coarse-grained sandstone, pebbly sandstone, and conglomerate. These beds are mostly normally graded and grad- ually pass into limestone (wackestone), or heter- olithic intervals composed of limestone (wacke- stone) interbedded with thin beds and laminae of shale (Fig. 4a). A bed of slumped pebbly mudstone approx. 2 m thick follows after a sharp erosive sur- face. Muddy matrix forms 80 % of this bed. Dis- persed within the matrix of the pebbly mudstone are clasts of shale, sandstone, and limestone up Fig. 8. Sedimentary log of the Jesenica 2 section. Right-side mark- ings delineate grain sizes: Cy- clay, Si- silt, vf- very fine sand, f- fine sand, m- medium sand, c- coarse sand, vc- very coarse sand, g- granule, p- pebble. 81Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia to 20 cm in size. The following 1.5 m of the sec- tion is covered. The covered interval is followed by a fining-upward succession 31 m thick. The lowermost 7.6 m of the interval is mostly sand- stone, with subordinate locally bioturbated shale (Fig. 4b). Sandstone beds are up to 70 cm thick, with erosional, locally channelized bases and with cross, planar lamination, f laser bedding, and rip- ple marks on some of the upper bedding planes. Three sedimentary sequences were singled out in the next 25.4 m of the section (from approx. 18 m to 45 m in Fig. 10) and are 7.4 m, 9.6 m and 8.4 m thick. Each sequence begins with beds of normally graded of conglomerate up to 40 cm thick, transi- Fig. 9. Sedimentary log of the Novaki sections. Right-side markings delineate grain sizes: Cy- clay, Si- silt, vf- very fine sand, f- fine sand, m- medium sand, c- coarse sand, vc- very coarse sand, g- granule, p- pebble, co- cobble. 82 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE tioning to planar- and cross-laminated sandstone. This is followed by 40 cm to 3 m thick shale-dom- inated heterolithic intervals with 10-40 % thin beds, laminae, and lenses of fine-grained sand- stone and thin beds of limestone (wackestone). Load casts are present on the lower bedding planes of sandstone, and ripple marks were observed on some of the upper bedding planes (Fig. 4c). Some upper parts of the sandstone beds are weath- ered and pass into brown mudstone some few cm thick. After a 13.4 m thick covered part of the section, a 16.2 m thick succession of heterolithic shale-dominated interval follows. Intercalations of thin beds, laminae, and lenses of cross-lam- inated fine-grained sandstone represent 15 % of the interval. Load casts are present on the lower bedding planes of sandstone beds. Ripple marks are present on the upper bedding planes. Shale is often bioturbated. The heterolithic clastic interval is followed by a predominantly calcareous, heter- olithic interval 2 m thick containing 70–85 % of limestone (wackestone) in beds 10–15 cm thick, and 15–30 % of shale in thinner beds. The interval is overlain by 1 m of bedded fine crystalline dolo- stone. The section ends with a clastic heterolithic interval 1.4 m thick with the same characteristics as the underlying one. The Davča 2 section spans 21.5 m of a carbon- ate-dominated succession (Fig. 10). The lower 10.2 m thick succession is characterized by in- creasing terrigenous component. The lowermost, 6 m thick part consists of limestone-dominated heterolithic intervals. Limestone (wackestone) in beds up to 20 cm thick forms 10–95 % of intervals and interchanges with thin beds of shale. Most of the contacts between the two lithologies are wavy. Heterolithic parts are interbedded by packages of bedded limestone (wackestone) 1 m thick. The lower part of the section ends with 4.2 m of shale, above which follow 5.8 m of calcareous-prevailing succession with heterolithic intervals containing 60–90 % of limestone (wackestone) interbedded by shale. Pyrite can be found in the lower part. Shale is locally bioturbated and ripple marks were observed on some bedding planes of limestone beds. Small chert nodules are present within the limestone in the upper part of the succession. The section ends with an interval of f ine crystalline dolostone 5.6 m thick in beds 5–50 cm thick be- longing to the lowermost part of the Bača dolomite formation (Fig. 4d). Dolostone often contains chert nodules and chert horizons up to 10 cm thick. The Poče section represents the upper 128 m of the Amphiclina formation (Fig. 11). The section is interrupted by two covered parts that are 9 m and 25 m long respectively and is dissected by three minor faults. The section begins with a 14.6 m thick coarsening-upward siliciclastic-dominated succession. The lower, 11 m thick part consists of shale that is interbedded with fine-grained sand- stone. The upper part comprises 0.7–1.3 m thick sequences composed of normally graded and part- ly planar-laminated sandstone, intercalated by beds of shale up to 30 cm thick. The next 5 m of the section consists of a heterolithic interval in its lower part. The heterolithic interval is composed of 75 % of shale and 25 % sandstone lenses. Up- wards, the interval transitions into an interval of shale 4 m thick with a thin lenticular bed of lime- stone (mudstone). The next, 9 m thick part of the section is covered, and is followed by a predomi- nantly shaly succession 22 m thick. In the lower part (4 m) is a heterolithic interval with 80 % shale, interbedded with fine-grained sandstone and thin beds and lenses of limestone (wackestone). The upper part of the interval consists of an interval of shale 18 m thick with two thicker beds of fine- grained sandstone. The succession is interrupted by a minor fault. Three heterolithic intervals fol- low, the first of which is 4 m thick, and consists of 85 % shale and 15 % limestone in lenses 2 cm thick. The second and third heterolithic intervals consist of 80–95 % locally bioturbated shale, in- terchanging with thin beds, laminae, and lenses of fine-grained sandstone. The section is interrupted by a covered interval 25 m thick. After the covered interval, a succession of bedded limestone (wacke- stone) 2.8 m thick follows. It is interbedded by a calcareous conglomerate with limestone and chert pebbles. This interval is overlain by a calcareous conglomerate 2 m thick with rip-up clasts of shale. The limestone pebbles are up to 7 cm in diameter, and on the outer side crusted in finely crystalline quartz. Clasts are partly imbricated. The conglom- erate bed is followed by a package of beds of in- tra-bioclastic grainstone limestone that is cut by a minor fault. Above the fault, a 5 m thick interval of bedded limestone (wackestone) and heterolith- ic intervals follows. Heterolithic parts consist of 50–80 % of limestone (wackestone), interchang- ing with beds of shale up to 1 m thick. This lime- stone dominated interval is overlain by a 14 m thick clastic heterolithic interval consisting of shale (75 %) and sandstone (25 %) in thin, partly cross-laminated beds, laminae, and lenses. Load casts are often present on lower bedding planes. The heterolithic interval is followed by three thick sequences, each 2 m thick. Sequences start with heterolithic interval up to 1.4 m thick composed of 80 % bedded limestone (wackestone) and 20 % 83Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia shale. The heterolithic parts are followed by clas- tic heterolithic intervals 0.8–1.4 m thick with 80– 90 % of shale, interbedded with fine-grained sand- stone in thin beds, laminae, and lenses. Load casts are present on some of the lower bedding planes. Ripple marks are present on the upper bed surfac- es. Two more sequences follow, which are 1.6 m and 3 m thick, respectively. The lower one starts with bedded limestone (wackestone), followed by a heterolithic interval consisting of 80 % limestone (wackestone) and 20 % shale. A lens of calcareous conglomerate is present near the base. The upper interval is shale-dominated, with 15–50 % of the interval limestone (wackestone). The transition from the Amphiclina formation to the Bača dolo- mite formation lies within a heterolithic interval 2 m thick, containing 80 % of fine crystalline do- lostone interbedded by 15 % of shale. Fig. 10. Sedimentary log of the Davča sections. Right-side markings delineate grain sizes: Cy- clay, Si- silt, vf- very fine sand, f- fine sand, m- medium sand, c- coarse sand, vc- very coarse sand, g- granule, p- pebble, co- cobble. Letterings: W- wackestone, C- crystalline. 84 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE The transition from the uppermost Amphiclina formation into the Bača dolomite formation in the surroundings of the village of Zakojca is exposed in two sections (Fig. 12). The section Zakojca 1 represents a succession of sedimentary rocks 15 m thick. The lowest 12 m of the section consists of two sedimentary sequences with an upwardly increasing clastic component. The sequences are 7 m and 5 m thick, respective- ly. The lower parts contain heterolithic intervals 1–4.4 m thick with 60–70 % dark grey limestone (wackestone) in beds 5–25 cm thick interchanging with shale (30–40 %) in thin beds and laminae. The section continues with clastic, shale-dominat- ed intervals 2.6–4 m thick with 70 % shale inter- changing with 30 % fine-grained sandstone in thin beds and lenses. The uppermost part of this 3-m thick section is dominated by carbonate rocks. It begins with limestone (wackestone) followed by partly dolomitized limestone. The section ends with a heterolithic interval 1.6 m thick consist- ing of fine crystalline dolostone (85 %) in beds 10–20 cm thick with chert nodules up to 20 cm in size interbedded by thin beds of shale (15 %). This interval belongs to the lowermost part of the Bača dolomite formation. Fig. 11. Sedimentary log of the Poče section. Right-side markings delineate grain sizes: Cy- clay, Si- silt, vf- very fine sand, f- fine sand, m- medium sand, c- coarse sand, vc- very coarse sand, g- granule, p- pebble, co- cobble. Letterings: W- wackestone, G- grainstone. 85Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia Section Zakojca 2 is located 300 m to the west of the former section, separated from it by a strike- slip fault. It was logged in a thickness of 35 m. It begins with a heterolithic interval 60 cm thick dominated by limestone (wackestone), interbed- ded with thin beds of shale. It is overlain by a bed of calcareous breccia 2.4 m thick with limestone clasts up to 50 cm in diameter. Clasts are silicified at the margin and partly imbricated. This breccia is very similar in composition and structure to the limestone conglomerate bed in the Poče section. The breccia is succeeded by a heterolithic inter- val 7 m thick containing 75 % limestone (wacke- stone) in beds up to 50 cm thick interbedded with thin beds of shale and a bed of calcareous breccia. This interval was partly eroded by a 2 m thick ma- trix-supported very coarse breccia with limestone clasts up to 1.5 m in size. The breccia passes into a 1.8 m thick bed of inversely graded muddy con- glomerate with limestone pebbles 4–5 cm in diam- eter. The amount of muddy matrix is lower than in the former breccia layer. Breccias are followed by a 2 m thick bed of inversely graded fine- to me- dium-grained calcarenite and a 1.6 m thick bed of calcareous breccia. The latter is overlain by a bed of matrix-supported limestone breccia 1.8 m thick with an erosional base. It is succeeded by a 1.4 m thick interval of medium-grained sandstone, limestone (wackestone) and shale. An erosion- al channel up to 30 cm deep is cut into the shale, and is filled with calcareous conglomerate with an admixture of smaller pebbles of quartz, rhyolites, chert, and sandstone. The conglomerate is followed by limestone (wackestone). Both are partly cut by matrix-supported breccia 4–5 m thick with clasts of sandstone and shale. The channel is oriented in a N–S direction. The muddy breccia is followed by 7 m of shale. The section ends with a heterolithic interval 2 m thick consisting of 85 % bedded, fine- ly crystalline dolostone and 15 % shale belonging to the Bača dolomite formation. The Orehek section is a heterogeneous succes- sion approx. 430 m thick (Fig. 13). It starts with 5 m of shale with rare calcareous nodules. Above the erosional surface follows an approximately 15 m thick, matrix-supported blocky olistostrome breccia with deformational textures (from 5 m to 20 m in Fig. 13). Limestone clasts (olistoliths) are Fig. 12. Sedimentary log of the Zakojca sections. Right-side markings delineate grain sizes: Cy- clay, Si- silt, vf- very fine sand, f- fine sand, m- medium sand, c- coarse sand, vc- very coarse sand, g- granule, p- pebble, co- cobble. Letter- ings: W- wackestone, C- crystalline. 86 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE Fig. 13. Sedimentary log of the Orehek section. Right-side markings delineate grain sizes: Cy- clay, Si- silt, vf- very fine sand, f- fine sand, m- medium sand, c- coarse sand, vc- very coarse sand, g- granule, p- pebble, co- cobble. Letterings: W- wackestone, G- grainstone. 87Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia up to 10 m in size. The olistostrome passes upwards into calcareous breccia, which in turn passes into sandstone. Another 9 m thick olistostrome with an erosional base follows (from 27 m to 36 m in Fig. 13). It is overlain by 37 m of shale with rare calcar- eous nodules and a heterolithic interval consisting of 65 % sandstone and 35 % shale. The following two olistostromes, 17 m and 43 m thick, respec- tively, contain olistoliths up to 20 m in size. An internal deformational fold axis indicates slump- ing towards the E-NE. The second olistostrome is overlain by calcareous sandstone, sandy shale with calcareous nodules, and limestone (wackestone) in a partly covered, 16 m thick interval (from 134 m to 150 m in Fig. 13). Passing a smaller fault, the succession continues with an olistostrome 18 m thick with smaller clasts. Olistostrome interca- lates with coarse-grained sandstone gradually passing into shale. This is overlain by a succession of limestone, interbedded with sandy limestone breccia and calcarenite 29 m thick (from 168 m to 197 m). This interval includes a limestone block (mud mound or olistolith?) 3.5 m thick covered by calcarenite and dark grey, locally laminated lime- stone (grainstone) in beds 3–40 cm thick passing into limestone breccia. The limestone-dominated interval is succeeded by a clastic succession 28 m thick containing a shale-dominant heterolithic in- terval at the base, followed by sandstone in mostly normally graded beds up to 3 m thick with planar lamination at the top. A sandy interval is followed by a heterolithic interval 15 m thick consisting of 65 % medium-grained sandstone interbedded with shale and topped by coarse-grained sandstone. The heterolithic interval is followed by 33.5 m of shale-dominated heterolithic intervals 7–18 m thick containing 30–90 % shale and 10–70 % dark grey limestone (wackestone), interbedded by beds of calcareous conglomerate and limestone (wackestone) 1 m thick. An olistostrome approx. 58 m thick follows (starts slightly below 272 m in Fig. 13) and is divided into four sections according to predominant lithology. The first section con- sists mostly of calcareous breccia with clasts of limestone (wackestone) up to 70 cm large contain- ing echinoderms. The following interval consists of a sandy conglomerate with pebbles of quartz, rhyolite, chert, limestone (mudstone), shale, and coarse-grained sandstone. This interval is over- lain by matrix-supported sandy breccia with an erosive base. Clasts within the breccia are pre- dominantly dark grey limestone (mudstone), up to 1 m in diameter. Breccia is overlain by a hetero- lithic interval, consisting of 70 % sandstone and 30 % shale. The upper part is covered, except for 58 m of olistostrome breccia. The lower part of the breccia includes an olistolith 24 m thick composed of normally graded, planar-, and cross-laminated sandstone with shale intercalations. The olistos- trome is covered by a heterolithic interval 17 m thick (from 330 m to 347 m) with 70 % sandstone and 30 % shale. Approximately 40 m of the section are poorly exposed. Shale and sandstone outcrop locally. An interval of limestone breccia approx. 9 m thick, passing into coarse-grained calcarenite follows. After 14 m of covered part the Bača dolo- mite formation follows. The Hudajužna section reaches a thickness of 66 m. It is composed of carbonate-clastic depos- its that represent the upper part of the Amphic- lina formation. The top of the section lies approx. 15 m below the contact with the Bača dolomite formation (Fig. 14). Conodonts studied by Flügel and Ramovš (1970) from a section in the vicinity provided late Carnian, Tuvalian age. According to a prevailing lithology, the section can be divided into two parts: the lower part is 20 m thick and largely consists of heterolithic intervals up to 2 m thick. Each interval consists of 70–95 % limestone (wackestone), and 5–30 % shale, and is interbed- ded by beds of limestone (wackestone) 40–60 cm thick and two beds of calcareous conglomerate, 1.4 m and 0.4 m thick, respectively. The second part, some 46 m thick and consisting mostly of shale occupies the rest of the section. The succes- sion is characterized by the increasing-upwards content of the calcareous component. The heter- olithic intervals alternate between predominant- ly limestone and shale and form sequences rang- ing from 0.4 m to 11 m in thickness. Sequences most often start with heterolithic intervals that are 0.8–3.4 m thick, consisting of 40–95 % lime- stone (wackestone) and 5–60 % shale, or with beds of limestone (wackestone) 20–40 cm thick. The upper, clastic-dominated heterolithic inter- vals include 70–95 % of shale, interbedded with thin beds, laminae, and lenses of very fine- to fine-grained sandstone. Shale is partly biotur- bated. Some sandstone beds are planar- and/or cross-laminated and have ripple marks on some of the upper bedding planes. The Koritnica section is the westernmost logged section. Beds are in an overturned position, slight- ly folded in the lower third of the section, and inter- sected by a minor normal fault with a displacement of about 2 m. Both irregularities were restored, so the complete section is present. The section com- prises a succession 89 m thick of a highly variegat- ed exchange of lithology: shale, bedded limestone (texturally mostly wackestone, subordinate pack- 88 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE stone, and grainstone), calcarenite, muddy breccia and conglomerate, and sandstone and dolostone with chert in the uppermost part of the section (Fig. 15). The complete succession was divided into ten intervals of different thickness and with specific characteristics. The first interval is 1.4 m thick and includes shale and limestone (mud- to wackestone). The second interval is 5.6 m thick and begins with muddy f lat pebble calcareous conglomerate with erosional lower and upper bed- ding plane, followed by interchanging calcareous conglomerate, calcarenite, some normally graded, and heterolithic intervals with 20–70 % of shale interbedded with limestone (mud- and packstone). The third interval is 10.8 m in thickness (approx. 7 m to 17.8 m in Fig. 15). Limestone (wackestone) is dominant, composed mostly of heterolithic in- tervals 0.8–3 m thick with 70–80 % limestone, 20–30 % shale, and 20–100 cm thick packages of bedded limestone interbedded with calcareous conglomerate and calcarenite. The fourth interval (from 17.8 m to 31.6 m) is 13.8 m thick and clas- tic-dominated, containing beds of conglomerate 20–80 cm thick. Some beds are calcareous, mud- dy breccia, sandstone, and calcarenite, interbed- ded by a heterolithic interval 0.6–1.4 m thick with 50–70 % limestone (wackestone) and 30–50 % shale. In this interval, two sandstone beds with ripples indicate the N–S direction of the current (at 23.5 m and 25.5 m). The fifth interval (from 31.6 to 43.2 m) measures 11.6 m in thickness. It is also dominated by clastic components. Four f ining-upward successions start (at 31.5 m in Fig. 15) with beds of breccia 40-80 cm thick with an erosional base (Fig. 4f ), passing upwards into coarse- to medium-grained sandstone, usually normally graded, interbedded with thin limestone (wackestone) beds or heterolithic intervals up to 60 cm thick with 85 % limestone (wackestone) and 15 % shale. In one of them, a thin bed of finely crystalline dolostone was detected. The upper part of the succession comprises two heterolithic in- tervals consisting of 60–85 % bedded limestone (wackestone), and 15–40 % shale interbedded with calcarenite. The sixth interval (from 43.2 to 59.4 m) occupies 16.2 m of the section and shows the coarsening-upwards trend. The lower part of the succession consists of interchanging thin beds of calcareous breccia, subordinate siliciclastic conglomerates, limestone (wackestone), and het- erolithic intervals, some of which are calcareous and some siliciclastic-dominant, and a thin bed of finely crystalline dolostone. Sedimentary slumps were observed in two intervals. It is important to mention a heterolithic interval 1.4 m thick with 60 % shale and 40 % sandstone in which beds are broken and folded around a block of bedded limestone (at app. 46 m in Fig. 15; Fig. 4e). The limestone block apparently slid from N to S, in- dicating slope inclination in the same direction. The upper part of the succession is composed of siliciclastic conglomerate and muddy breccia up to 1.4 m thick, both with erosional bases interbed- ded with limestone in thin lenses and filling small depressions on uneven upper bedding surfaces Fig. 14. Sedimentary log of the Hudajužna section. Right-side mark- ings delineate grain sizes: Cy- clay, Si- silt, vf- very fine sand, f- fine sand, m- medium sand, c- coarse sand, vc- very coarse sand, g- granule, p- pebble, co- cobble. Letterings: W- wackestone, P- pack- stone. 89Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia of conglomerate, which are somewhere overlain by normally-graded sandstone or dunes with ripple marks. The seventh interval is 7.6 m thick with a f ining-upward beds track. It begins with a chan- nelized erosional surface cutting some 80 cm into underlying sediments (at app. 59 m in Fig. 15) and is overlain by two sequences with calcareous conglomerate with elongated, partly imbricated limestone clasts up to 50 cm in size, followed by sandstone or limestone (wackestone). The upper sequence also has a channelized erosional base. Channels run in the N–S direction. The succession ends with a heterolithic interval 3.4 m thick con- sisting of 90 % bedded limestone (packstone) and 10 % shale (from 63.5 m to 67 m in Fig. 15). The eight interval, which is 8 m thick, can be divid- ed into two parts: the lower, 4.2 m thick, mostly contains inversely graded fine- to coarse-grained sandstone; the thickest bed at 2 m is inversely graded into siliciclastic conglomerate, which in the uppermost part is muddy and contains only limestone pebbles. The upper part is 3.8 m thick. It starts with channelized erosional surface (71 m in Fig. 15), overlain by a thin layer of conglomer- ate, followed by normally-graded coarse- to fine- grained sandstone, which is in the upper parts planar- or cross-laminated. Ripple marks are lo- cally present. The sandstone is dolomitized. The Fig. 15. Sedimentary log of the Koritnica section. Right-side markings delineate grain sizes: Cy- clay, Si- silt, vf- very fine sand, f- fine sand, m- medium sand, c- coarse sand, vc- very coarse sand, g- granule, p- pebble, co- cobble. Letterings: M- mudstone, W- wackestone, P- pack- stone, G- grainstone, C- crystalline. 90 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE ninth interval is 7.1 m thick, consisting of hetero- lithic intervals dominated by bedded dolostone or limestone. The heterolithic intervals are 1.2–2.6 m thick. They consist of 60–90 % bedded dolostone and 19–40 % shale. The limestone-dominated het- erolithic interval, 1.8 m thick, consists of 80 % limestone (packstone) and 20% shale. The succes- sion is capped by a lens of limestone (wackestone) with some ripple marks (75 m in Fig. 15). The tenth interval covers 11 m of the section and con- sists of bedded crystalline dolostone and a hetero- lithic interval 2.4 m thick dominated by dolostone with 10 % of shale. The dolostone contains nodules and thin, uneven beds of chert. This interval be- longs to the Bača dolomite formation. Microfacies Table 2 lists microfacies varieties of clastic sedimentary rocks and limestone from the upper Pseudozilja and Amphiclina beds. Late diagenetic changes are omitted from the description. Volca- nics and volcanoclastics of the Malenski Vrh sec- tion were already described by Skaberne and Čar (1986). Selected microfacies types of limestones and coarser (sand- to gravel-size) clastic rocks are pre- sented in Figures 16–18. Limestone comprises a variety of microfacies types. The most common is wackestone, dominated by thin-shelled bivalves, echinoderms, and radiolarians. Also common are carbonate mudstone and radiolarian wackestone, whereas other limestone types are less common. Sandstone is mostly dominated by quartz, feld- spar, and lithic grains (mostly fragments of acidic volcanic rocks) in various proportions. Rare bio- clasts, such as thin-shelled bivalves, and echino- derms, are found in sandstone. A single silicified foraminifera Lamelliconus ex gr. ventroplanus (Oberhauser) was found in one sample (Fig. 18c). The stratigraphic range of L. ex gr. ventroplanus extends from the Ladinian to the Carnian (Rettori, 1995; Pérez-López et al., 2005). Microfacies Composition Interpretation Samples Carbonate mudstone (Fig. 16a) Less than 10 % of clasts (mostly bioclasts, small admixture of terrigenous grains); micritic matrix predominates. Different degrees of bioturbation. Elongated grains oriented parallel to the bedding (could be due to compaction). Rare samples show faint paral- lel lamination. Bioclasts: echinoderms, fragments of thin-shelled bivalves, sponge spicules. Terrigenous grains: include quartz, feldspar, mica. Hemipelagic background sedimentation. Hudajužna: 10.5, 17.4, 24.6, 38.5, 45.8, 62.0; Davča 1: 20.4; Davča 2: 18.9, 23.3; Jesenica 2: 1, 4, 5, 9; Poče: 1, 2, 9, 11, 15, 28, 37; Koritnica: 48.6, 59.4, 96.4. Filament- echinoderm wackestone and packstone (Fig. 16b–c) 10–50% of grains (bioclasts, some samples with 0–2% of terrigenous grains), 50–90% of micritic matrix. Poorly to moderately sorted; elongated grains concordant to bedding. Possible bioturbations locally present. Locally interchanges with bioclas- tic packstone in laminae. Some samples with geopetal structures (um- brella-type porosity beneath valves, geopetal infillings of gastropods). Bioclasts: dominant thin-shelled bivalves (fragmented), echinoderms (often bored); subordinate radiolarians, sponge spicules, gastropods, ostracods, foraminifera. Terrigenous grains: poorly preserved, strongly carbonatized; feldspar, fragments of volcanics, quartz. Some samples contain very rare intraclasts. Hemipelagic back- ground sediment, mixed with alloch- thonous compo- nents; reworked by bioturbation and/or weak currents. Hudajužna: 1.7, 3.2, 9.1, 9.6, 10.8, 12.5, 14.2, 15.7, 18.4, 19.5, 28.8, 41.1, 52.0, 56.7; Davča 1: 2.7, 5.5, 33.5, 94.7; Davča 2: 2.7, 3.5, 5.7, 10.3, 13.9, 15.3; Poče: 3, 9, 11, 12, 15; Zakojca 1: 2, 2a, 14, 20.6, 47; Koritnica: 11.6, 15.7, 39.5, 83.7. Filament packstone (Fig. 16d) 80% of grains, 20% of microsparite and carbonate cement. Faint parallel lamination, caused by different amount of peloids. Thin- shelled bivalves are parallel to bedding, in long contacts. Grains: thin-shelled bivalves predominate (70% of rock); peloids and echinoderms together represent 10% of rock. Reworked hemipe- lagic sediment. Zakojca 2: 53; Koritnica: 57.4, 91.6, 95.8. Radiolarian wackestone (Fig. 16e) 15–30% of grains (mostly bioclasts), 70–85% of micritic matrix. Grains are poorly sorted. Bivalves are oriented parallel to bedding. Umbrella-type porosity under the valves is present in some samples. Bioclasts: dominant radiolarians, followed by thin-shelled bivalves, gas- tropods, echinoderms, thick-shelled bivalves, ostracods, foraminifera. Terrigenous grains are rare, including grains of quartz and lithic grains. Lithoclasts of carbonate mudstone are also sporadically present. Hemipelagic background sedimentation. Hudajužna: 36.2; Davča 1: 2.3, 43.0, 75.0, 97.8; Davča 2: 0.7; Poče: 11, 24, 26; Zakojca 2: 17, 20.6; Koritnica: 12.0, 45.8, 80.8. Bioclastic wackestone (Fig. 16f) 20% of grains, 80% of micritic matrix. Grains are well sorted, less than 0.5 mm in size. They comprise angular sparitic fragments of bioclasts. Diluted gravity flow deposit (wan- ing turbidite)? Poče: 7. Table 2. Description of microfacies types from the Ladinian – Carnian volcano-sedimentary succession of the western Slovenian Basin. 91Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia Crinoid wackestone and packstone (Fig. 16g) 40% of grains, 40% of micritic matrix, 20% of syntaxial calcite cement. Grains are overall poorly sorted, but individual components show good sorting. Grains are matrix supported or are in point, rarely planar contacts. Grains: predominant are echinoderms predominate (30–35% of rock); subordinate are thin-shelled bivalves, fragments of brachiopods, litho- clasts (intraclasts?) of carbonate mudstone. Diluted gravity flow deposit (wan- ing turbidite)? Poče: 8; Zakojca 2: 30; Koritnica: 83.7. Peloid packstone (Fig. 16h) 50% of grains (peloids), 50% of recrystallized micritic matrix. Microfacies is very limited in extent, associated with carbonate mudstone. Peloids are very well sorted, rounded, in point contacts and elliptical in shape due to compaction. Fragments of thin-shelled bivalves and ostra- cods are rarely present. Very diluted gravity flow de- posit (waning turbidite)? Poče: 2; Koritnica: 57.4. Pelletal- bioclastic packstone 60% of grains (35% pellets, 15% bioclasts), 40% of micritic matrix, 10% of terrigenous grains. Poorly to moderately sorted. Locally weakly expressed parallel lamina- tion indicated by a greater proportion of non-calcareous grains. Some samples are bioturbated. Bioclasts: dominantly thin-shelled bivalves; subordinate ostracods, radiolarians. Terrigenous grains: unequally distributed, angular; mostly feldspar, subordinate quartz, sericite. Cement: syntaxial rim. Hemipelagic background sed- imentat, mixed with allochtho- nous components; reworked by bio- turbation and/or weak currents. Hudajužna: 41.1; Poče: 9, 11; Koritnica: 39.5. Bioclastic- intraclastic packstone (Fig. 17a) 60% of grains (50% bioclasts, 10% intraclasts), 5–35% micritic matrix, 5–35% calcite cement. Moderately sorted. Bioturbated, partly laminated. Bioclasts: dominant thin-shelled bivalves (concentrated in laminae, most fragmented), echinoderms; subordinate radiolarians, gastropods, fora- minifera (Nodosaria ordinata Trifonova, Endoteba sp.). Intraclasts:carbonate mudstone, 0.06–1.5 mm in size; subrounded, mod- erately sorted. Cement: granular and syntaxial rim. Hemipelagic background sed- imentat, mixed with allochtho- nous components; reworked by bio- turbation and/or weak currents. Hudajužna: 7.3; Zakojca 2: 3, 8, 5.1; Koritnica: 86.6, 90.5. Intraclastic- bioclastic packstone 75% of grains (50% intraclasts, 20% bioclasts, 5% terrigenous grains), 20% of micritic matric, 5% of cement. Normal grading. Grain size 0.1–2 mm (dominant 0.2 mm), well sorted. Grains are in point, planar, rarely concavo-convex contacts. Elongated grains are oriented parallel to the bedding. Bioclasts: fragmented bivalves, echinoderms, foraminifera. Intraclasts are micritic, rounded. Terrigenous grains: subangular to subrounded; include quartz, feldspar, lithic grains (volcanics, chert). Cement: granular and syntaxial rim calcite cement. Gravity flow depo- sit (turbidite?). Koritnica: 16.5, 28.4, 51.4, 70.1. Intraclastic- bioclastic grainstone (Fig. 17b, c) 50% of grains, 50% of carbonate cement. Grains are moderately sorted, of average size 0.4 mm. Intraclasts (car- bonate mudstone, rarely peloidal grainstone) represent 30% of the rock. Bioclasts (echinoderms, foraminifera, bivalves) form 20% of the rock. Gravity flow depo- sit (turbidite?). Davča 1: 97.7; Zakojca 1: 7.9. Bioclastic floatstone with bioclasti- c-intraclastic grainstone matrix (Fig. 17d) 50% of grains (40% of bioclasts, 10% of intraclasts), 50% of carbonate cement. Grains are poorly sorted, between 0.05 mm and 2 cm in size (the largest grain is a fragment of a solenoporacean algae, overgrown by a thin crust of microbialite). Average grain size is 0.75 mm. Larger grains are oriented parallel to bedding and elongated due to compaction. Bioclasts are dominated by sparitic particles (solenoporacean algae, but most are unrecognisable); echinoderms are rare. Gravity flow depo- sit (turbidite?). Poče: 6, 7. Sandy mudstone (Fig. 17e) Silt-sized grains predominate. Sand grains (up to 0.15 mm in size) repre- sent app. 10% of the rock. They comprise quartz, feldspar, and opaque grains. Grains are somewhat rotated due to compaction; pseudo fluvial texture is visible. Some samples show parallel lamination. Diluted gravity flow deposit. Jesenica 2: 4; Poče: 2, 10, 14, 16, 21, 25, 27, 40, 43. Fine-grained sandstone (Fig. 17f–h) 60–70% of grains, 25% of calcite cement, 5% of other cement, up to 20% of epimatrix. Locally interchanging in laminae with pebbly, sandy mudstone. Grains are 0.03–0.25 mm (mostly 0.07 mm) in size, angular to subrounded, isometric to elongated. They are in point, planar and concavo-convex contacts. Elongated grains are oriented parallel to the bedding. Grains: quartz, feldspar, lithic grains, biotite, heavy minerals (opaque minerals, zircon, rutile). Gravity flow deposit. Črni Vrh: 1, 1.3, 3, 4.5, 6, 8, 10; Davča 1: 85.5; Davča 2: 5.0; Jesenica 1: 2, 5, 6, 8; Novaki: 28.1, 40.0, 62.9; Poče: 2, 10, 14, 18, 21, 33, 37, 42; Zakojca 1: 5.4; Zakojca 2: 3.0; Koritnica: 26.6, 33.5, 41.1, 61.9, 69.0. 92 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE Medium- grained sandstone (Fig. 18a–c) 40–70% grains (10–20% quartz, 10–30% feldspar, 20–45% lithic grains), 25–60% cement, 1–5% epimatrix. Homogeneous structure or parallel lamination, caused by the difference in grain sizes or concentration in accessory heavy minerals. Some sam- ples are graded. Elongated grains are oriented parallel to the bedding. Grains are poorly to moderately sorted; grain size 0.04–2 mm (dominant size 0.3–0.5 mm). Grain shape isometric to elongated, angular to round- ed. Grains are in point, planar, concavo-convex or stylolitic contacts, rarely matrix-supported. The least abraded grains belong to quartz, often present as subhedral crystals. Grains: dominant (in different order) are feldspar (plagioclase and alkali feldspars), lithic grains (rhyolite and granitoids; very rare micritic lime- stone), quartz (mostly monocrystals, some with embayment structures); accessory are heavy minerals (zircon, rutile, titanite, opaque minerals) and mica (biotite, muscovite). Some samples with notable presence of carbonate mudstone lithoclasts (intraclasts). Very rare are bioclasts (fragments of bivalves, echinoderms, very rare fragments of thick-shelled bivalves). Cement: calcite, dolomite and feldspar. Gravity flow deposit. Črni Vrh 4: 0.7, 0.8, 1.6, 2, 2.5, 5, 12; Hudajužna: 22.0, 23.8, 31.8, 44.6, 64.8; Davča 1: 1.0, 8.9, 12.5, 13.8, 19.6, 27.5, 35.1, 38.9, 95.8; Novaki 1: 1, 3, 18, 84.7; Poče: 17, 18, 19, 22, 34, 36, 41; Koritnica: 43.9, 48.6, 63.7. Coarse- grained sandstone (Fig. 18d) 60–80% of grains, 5–20% of epimatrix, 5–40% of carbonate cement. The amount of epimatrix increases with grain compaction. Grains are 0.15–2.5 mm in size, although most are in the range between 0.45 mm and 0.79 mm. They are poorly sorted, subangular to angular, isometric to slightly elongated. Planar contacts prevail, while point, con- cavo-convex and stylolitic contacts are locally present. Grains: quartz (monocrystals, rarely polycrystalline), feldspar, lithic grains (volcanics, mudstone); subordinate are opaque minerals and bio- clasts (echinoderms, thin-shelled bivalves). Gravity flow deposit. Jesenica 1: 1, 7, 9; Jesenica 2: 3/1, 3/2, 6; Novaki: 10.3, 11.5, 18, 18.2, 27.5; Poče: 38; Zakojca 2: 18; Koritnica: 18.7, 33.5, 59.4. Coarse- grained peb- bly sandstone (Fig. 18e–f) 50–80% of grains (5–20% quartz, 10–30% feldspar, 30–50% lithic grains), 20–50% of matrix. Locally interchanging in laminae with fine-grained sandstone. 5–30% of grains larger than 2 mm, 40% of sand-sized grains, 50% of grains smaller than 0.03 mm. Grains are 0.03–7 mm in size, very poorly sorted. Larger grains are an- gular to well rounded. Smaller grains are mostly subangular to subround- ed. Grains are isometric, rarely elongated. Most grains are supported by matrix; some are in point, planar, concavo-convex or stylolitic contacts. Grains: quartz (monocrystals, most with undulating extinction, some with embayment structures), feldspar (plagioclase and alkali feldspars), lithic grains (acidic volcanic rocks, basic volcanic rocks, tuff, chert), acces- sory are zircon, opaque minerals, mica (biotite). Matrix mostly ortho- and pseudomatrix, along cracks and grains il- lite-sericite epimatrix showing pseudofluidal texture around grains. Epimatrix prevails in tectonically-stressed samples. Gravity flow deposit. Črni Vrh: 4, 4.5; Davča 1: 9.5, 85.5; Davča 2: 5.0; Novaki: 1.0, 6.3, 14.0, 21.5, 33.3, 51.6, 57.4, 60.7; Koritnica: 23.2, 24.6, 33.2, 61.5, 73.5, 76.1. Pebble breccia (lithoclastic rudstone) (Fig. 18g) 50% of clasts, 50% of carbonate cement. Clasts are poorly sorted. Their average size is 4 mm. The smallest grains measure 0.2 mm, while the largest grains measure 12 mm in size. Clasts are subangular to rounded. They comprise (not in order) carbonate mudstone, peloid packstone, filament mudstone, intraclastic-bioclastic wackestone-packstone, bioclastic grainstone, peloid grainstone, microbial boundstone, oncoids, bivalve shells, echinoderms, coral fragment, rhyo- lite lithoclasts, idiomorphic crystals of feldspar, quartz grains, and chert lithoclast. Gravity flow deposit. Poče: 4; Jesenica 2: 2, 7, 12; Koritnica: 15.7b, 55.3. Cobble breccia/ conglomerate (Fig. 18h) 85% of grains larger than 2 mm, 8% of grains smaller than 2 mm, 7% of cement. Grains in concave-convex and stylolitic contacts. Grain size 0.5–15 cm, poorly sorted, angular to rounded, most subrounded, isometric to elon- gated in shape. Grains: dominantly limestone clasts (mostly bioclastic wackestone, fol- lowed by carbonate mudstone, pelletal-bioclastic packstone, and bioclas- tic-intraclastic packstone with rare ooids). Sand-sized grains are of the same composition. Bioclasts are presented by echinoderms. Selective silicification. Gravity flow deposit. Hudajužna: 6.8; Koritnica: 31.0. 93Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia Fig. 16. Carbonate microfacies of the Ladinian – Carnian sedimentary succession of the Slovenian Basin (Pseudozilja and Amphiclina forma- tions). a: Carbonate mudstone. Arrowhead points at the echinoderm. Sample Davča D1:23.3. b: Filament-echinoderm wackestone. Sample Hudajužna H19.5. c: Filament-echinoderm packstone. Sample Hudajužna H9.1. d: Filament packstone. Sample Zakojca ZK2:53. e: Radio- larian wackestone. Arrowheads point at calcified radiolarians. Note also the presence of filaments. Sample Hudajužna H36.2. f: Bioclastic wackestone. Sample Poče PO1:7. g: Crinoid packstone. Sample Zakojca ZK2:30. h: Peloid packstone. Sample Poče Po1:2. 94 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE Fig. 17. Microfacies of the Ladinian – Carnian sedimentary succession of the Slovenian Basin (Pseudozilja and Amphiclina formations). a: Bioclastic-intraclastic packstone. Markings: e- echinoderm, i- intraclast. Sample Hudajužna H7.3. b: Intraclastic-bioclastic grainstone. Sample Davča D1:97.7. c: Intraclastic-bioclastic grainstone. Arrowhead points at the foraminifera. Sample Zakojca ZK1:7.9. d: Bioclastic floatstone with bioclastic-intraclastic grainstone matrix. Markings: b- bioclast, i- intraclast. Sample Poče Po:1.6. e: Sandy mudstone. White grains belong to quartz and felsic volcanic rocks. Sample Davča D1:85.5. f: Fine-grained sandstone. Sample Davča D1:85.5. g: Fine-grained sandstone. Sample Črni Vrh CV1:6. h: Same sample, crossed Nichols. White arrowheads point at quartz, green arrowheads point at grains of felsic volcanic rocks, yellow arrowheads point at feldspar. Quartz-sericite matrix is marked with “ep”. 95Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia Fig. 18. Microfacies of the Ladinian – Carnian sedimentary succession of the Slovenian Basin (Pseudozilja and Amphiclina formations). a: Medium-grained sandstone. Calcitization is revealed by staining. Sample Hudajužna H:64.8. b: Same sample, crossed Nichols. White ar- rowheads point at quartz, green arrowheads point at grains of felsic volcanic rocks, yellow arrowheads point at feldspar. c: Lamelliconus ex gr. ventroplanus (Oberhauser). Sample Novaki N1:18.0. d: Coarse-grained sandstone. The large grain in the middle belongs to volcanic rock. Sample Novaki N5:18.2. e: Coarse-grained pebbly sandstone. Sample Novaki N4:1.0. f: Same sample, crossed Nichols. White arrowheads point at quartz, green arrowheads point at grains of felsic volcanic rocks, yellow arrowheads point at feldspar. g: Pebbly breccia (lithoclastic rudstone). Sample Poče Po1:4. h: Cobble breccia. Sample Hudajužna H6.8. 96 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE Discussion One or two formations For over 150 years, the volcano-sedimentary succession underlying the Bača dolomite forma- tion has presented a considerable stratigraphic challenge. Based on the presence or absence of vol- canics and tuff, respectively, some distinguished between the Ladinian Pseudozilja formation and the Carnian Amphiclina formation (Rakovec, 1950; Turnšek et al., 1982; Buser, 1986; Buser & Ogorelec, 1987), even though the early descrip- tions of both formations, based on observations from different geographic areas, do not mention volcanics or tuffs (Stur, 1858; Teller, 1885, 1889; Kossmat, 1901, 1907, 1910, 1913). Other authors suggest that the two represent the same formation (Kossmat, 1910, 1913; Čar et al., 1981; Ogorelec, 2011). The main volcanism in the eastern South- ern Alps and the northern External Dinarides took place from the late Anisian to the early Ladinian (Gianolla et al., 1998; Kralj & Celarc, 2002; Dozet & Buser, 2009; Celarc et al., 2013; Smirčić et al., 2018; Gianolla et al., 2019; Kukoč et al., 2023; Oselj et al., 2023; Kukoč et al., 2024). However, reliably dated successions from the region show renewed volcanism in the late Ladinian and at the transition to the early Carnian (e.g. Jurkovšek, 1984; Kolar-Jurkovšek, 1991; Jelaska et al., 2003; Celarc, 2004, 2007; Kolar-Jurkovšek & Jurkovšek, 2019). Thus, the products of volcanism may in- deed be limited to the upper Anisian – uppermost Ladinian/lowermost Carnian successions. From the described sections, we summarize that the lithological compositions of the upper Pseudozilja and the Amphiclina formations (sensu Demšar, 2016) are virtually the same, comprising shale, siltstone, sandstone, bedded hemipelagic limestone, conglomerate, and breccia (including olistostromes) in varying proportions. Unfortu- nately, precise correlation between the sections is not possible due to the lack of biostratigraphic data. Although it would be expected from their position on the geological map that tuffs and/or volcanics would be present in the Črni Vrh (and maybe also in the Jesenica) sections this is not the case, even though the Črni Vrh section reaches 44 m in thick- ness. Volcanics and tuffs were recorded instead only in the Malenski Vrh section that belongs to the lower Pseudozilja formation. It must be em- phasized, however, that the Malenski Vrh section is located in a different tectonic unit, in the Trnovo Nappe, which belongs to the External Dinarides. Thus, a question appears whether the tuffs and/ or volcanics are common enough after the lower Ladinian to be useful as a distinct feature for the entire Pseudozilja formation. Instead, it could be said that volcanics and tuffs may indicate that the observed succession is of the late Anisian – lat- est Ladinian age, but their absence is not enough to recognize the observed unit as the Amphiclina formation. More sections from the upper Pseudoz- ilja formation should be logged in order to further substantiate this proposition. Sedimentary environment The depositional environment of the described volcano-sedimentary succession has mostly only been hinted at (e.g. Rakovec, 1950; Turnšek et al., 1982; Flügel & Ramovš, 1970; Ramovš, 2004). Flügel and Ramovš (1970) interpreted the sedi- mentation of muddy sediments in the aphotic zone of the sedimentary basin within low energetic water conditions, with interruptions of carbonate sedimentation. The sections from Zgornja Davča were already investigated by Babić and Zupanič (1978), who interpreted the limestone beds as au- tochthonous marine sediments, and the sandstone as sediment of turbidity currents in a relatively shallow basin. Ramovš (2004) suggested deposi- tion of fine-grained conglomerate, sandstone, and shale from turbidite f lows. Rakovec (1950), Čar et al. (1981), and Skaberne and Čar (1986) all envi- sioned deposition in the transitional zone between the shoreline and the shelf (Čar et al. 1981). An in- terpretation of the sedimentary environment will be given based largely on the logged sections, and later on, drawing from more regional aspects. The only section enclosing the lowermost succession of the Pseudozilja formation (sensu Demšar, 2016) is the Malenski Vrh section, which is, as mentioned before, located in an entirely different tectonic position, in the Trnovo Nappe, which belongs to the External Dinarides. The suc- cession of volcanic rocks followed by lithoclas- tic-crystalloclastic tuff with intercalations of di- abase uncomformably overlies the Lower Triassic oolitic limestone. The overlying, shale dominated succession with some larger sandstone lenses, in- terpreted as sand bars, indicates a relatively quiet shelf environment. The other sections, representing the upper Pseudozilja formation (Črni Vrh 3–4), the up- per Pseudozilja/the lower Amphiclina formation (Jesenica 1–2), and the lower Amphiclina forma- tion (Novaki 1–4) have similar lithological com- positions. Clastic sedimentary rocks prevail in all of these sections. The composition of conglom- erate and sandstone is dominated by siliciclas- tic components, by fragments of volcanic rocks 97Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia and their tuffs, followed by quartz and feldspar grains. In the muddy conglomerates that are pres- ent only in sections Jesenica 1 and 2, pebbles of sandstone predominate, although some limestone pebbles were also found in the Jesenica 2 section. Sediments were partly transported by turbidity currents and debris f lows, as indicated by sedi- mentary textures (normal grading for turbidites, matrix support for debris f low deposits), and part- ly as hemipelagic deposits. Small scour channels indicate a N–S direction of transport. The coars- ening-upward sequence of the Jesenice 1 section corresponds to the progradation of submarine fan deposits, with lower fan, dominated by turbidite deposits passing upwards into middle and per- haps upper fan, dominated by debris-f low deposits (Walker & Mutti, 1973). The somewhat larger number of sections (Davča 1–2, Poče, Zakojca 1–2, Orehek, Hudajuž- na, Koritnica) logging the upper Amphiclina for- mation (sensu Demšar, 2016) allows us to observe vertical and lateral differences in sediment com- position and in sedimentation within roughly the same stratigraphic interval. The Davča sections are the most eastward lying of these sections. The lowermost sedimentary succession of the Divača 1 section indicates predominantly calcareous and subordinate muddy hemipelagic sedimentation, interrupted by turbidity currents transporting sandy siliciclastic material. The rest of the sec- tion is characterised by predominately siliciclas- tic, f ining-upward, retrograding succession. It be- gins with slump/debris f low deposits followed by sandy deposits of proximal turbidites, passing into muddy hemipelagic deposits and distal turbidites. Limestone hemipelagic sediments prevail in the upper part of the section. The Davča 2 section is dominated by hemipelagic limestone. In the upper part of the section, the non-terrigenous siliceous component within the sediment increased and was later concentrated in chert nodules. The Hudajužna section and the lower part of the Poče section are characterized by the longest lasting relatively quiet sedimentary conditions. The lower part of the Hudajužna section compris- es mostly hemipelagic limestone, interrupted by higher energy currents, and depositing conglom- erate with limestone clasts. The upper part of the Hudajužna section and lower part of the Poče section indicate prevailing muddy sedimentation, interchanging with hemipelagic limestone sedi- mentation with intercalations of siliciclastic sandy sediments deposited by (mostly distal) turbidity currents. The Zakojca sections show quick lateral changes of sedimentary conditions. The Zakojca 1 section indicates relatively quiet, muddy and hemipelag- ic limestone sedimentation that was locally inter- rupted by distal turbidity currents. In contrast, the sedimentary successions in the Zakojca 2 sec- tion indicate energetic, highly variable, predom- inately high energy sedimentary conditions with debris f lows and high- and low-density turbidity currents, interchanging with hemipelagic sedi- mentation. In the lower two-thirds of the section, hemipelagic limestone prevails, with some admix- ture of siliciclastic components in the upper part. The uppermost muddy breccia deposited from de- bris f low, has only noncarbonate clasts, mostly of sandstone and shale. Debris f low was followed by hemipelagic muddy sedimentation. The orienta- tion of the erosional channels indicates transport in a N–S direction; the sediments were deposited on or near the continental slope. The Orehek section includes the thickest part of the upper Amphiclina formation and is character- ized by the most intensive slumping – debris f lows. Syndepositional folds indicate transport from the NE. Massive blocks of limestone from this section are currently interpreted as in-situ mud mounds. The Koritnica section is the westernmost sec- tion of the upper Amphiclina formation. Its hetero- geneous composition indicates particularly versa- tile sedimentary conditions. The lower part of the succession is dominated by hemipelagic carbonate sedimentation, interrupted by slumps/debris f lows, turbidity, and higher energy currents trans- porting calcareous and siliciclastic sediments. The middle part of the section shows the most dynamic sedimentary conditions and is dominated by slide, slump, debris f low, and turbidity current depos- its. The slumps indicate N to S transport of the sediment. Subordinate to the mass-f low deposits are hemipelagic sediments. Sedimentation largely took place on a slope generally inclined towards the south. To summarize, the upper Pseudozilja formation and the Amphiclina formation consist of hemi- pelagic deposits intercalated with sediment that was transported via slides, slumps, debris f lows, and turbidity currents. Sedimentation mostly took place on or near the continental slope, generally inclined towards the south, and the transport was largely from north to south. Only olistostromes in the Orehek section indicate a more easterly direc- tion of sedimentary transport. It appears that sedimentary conditions became more uniform towards the end of the Carnian, when carbonate sedimentation completely prevails 98 Dragomir SKABERNE, Jože ČAR, Maja PRISTAVEC, Boštjan ROŽIČ & Luka GALE over siliciclastics in all the sections. This could be due to the relative rise of the sea level, the shift of the coastline and/or change in the f luvial net- work, and the subsequent spreading of carbonate platforms (see Gianolla et al., 1998; Haas & Bu- dai, 1999; Gawlick & Böhm, 2000; Gianolla et al., 2003; Berra et al., 2010). Regional comparisons The described volcano-sedimentary succes- sion from the Slovenian Basin differs from con- temporaneous volcano-sedimentary formations in the region in its pronounced thickness and in its higher shale content. Depending on the palaeogeo- graphic position, the Pseudozilja/Amphiclina for- mations are succeeded either by the Bača dolomite formation in the late Carnian in the central part of the Slovenian Basin, or earlier (late Ladinian/early Carnian) by platform carbonates in the marginal parts of the basin (Šmuc & Čar, 2002). According to Placer and Kolar-Jurkovšek (1990), the southernmost exposure of the Pseu- dozilja formation is the Zagorje area in the Posav- je Hills. Considerable differences can be observed among individual sections further south, which structurally belong to the External Dinarides (see Dozet & Buser, 2009; Kolar-Jurkovšek & Ju- rkovšek, 2019; Oselj et al., 2023). Tuffs and vol- canogenic sandstone usually occur in association with bedded limestone, dolostone, and marlstone (Buser, 1974; Jurkovšek, 1984; Dozet, 2006). A thick succession some hundreds of metres thick of Ladinian volcano-sedimentary succession from the Rute plateau in central-southern Slovenia was recently described by Kocjančič et al. (2022) and Rožič et al. (2024). This laterally highly variable succession consists of packages of tuff, volcano- genic sandstone, shale, marlstone, laminated lime- stone (calcimudstone), hemipelagic limestone, and resedimented limestones (calcarenite and lime- stone breccia). In the Julian Alps and the Kamnik-Savinja Alps (Julian Nappes of the eastern Southern Alps), the volcano-sedimentary series occurs between Ani- sian platform limestone/dolostone (Contrin For- mation) and Ladinian massive carbonates of the Schlern Formation (Jurkovšek, 1987; Celarc et al., 2013; Goričan et al., 2022; Gale et al., 2023). The most widespread unit, which can be consid- ered the equivalent of the Buchenstein Formation from the western Julian Alps and the Dolomites (Celarc et al., 2013; Gale et al., 2023), consists of tuff, sandy claystone, marlstone, sandstone (some beds with plant fragments), and bedded limestone, with intercalations of volcanics and rarely volcan- iclastic breccia (Ramovš, 1990). Limestone locally contains numerous involutinid foraminifers, small coral colonies, and bivalves (Ramovš, 1990; Gale et al., 2023). In the smaller half-grabens developed on top of the Contrin platform the Buchenstein Formation locally overlies pinkish nodular pelagic limestone of the Loibl (Ljubelj) Formation, and tuff and rhyolites and/or pinkish nodular limestone of the Vernar member, and the Uggowitz Breccia (Celarc et al., 2013; Gale et al., 2023). The cumu- lative thickness of the upper Anisian – lower Lad- inian succession between the two platform units reaches up to a few tens of meters. Volcaniclastics also occur near the top of the Schlern Formation in the form of “pietra verde” tuffs associated with thin-bedded limestone with chert nodules and cal- carenites, described as the Korošica Formation (Jurkovšek, 1984; Celarc, 2004, 2007). Buchenstein-type facies is further present in many successions in Croatia and Bosnia and Her- zegovina (Smirčić et al., 2018). Much thinner silici- clastic-dominant facies than in the Tolmin Nappe was documented in the Donje Pazarište section on the Velebit Mts. The series consists of 18 m of volcaniclastic (lithic) sandstone and shale, and 28 m of carbonate shale. Akin to sandstone from the herein described sections, sandstone from Don- je Pazarište shows planar and cross lamination, and grading. The siliciclastic facies deposited via turbidity currents in a deepened basin, probably on a distal part of a submarine fan (Smirčić et al., 2020). The following lithologies consist of pyro- clastic density-current facies, platy limestone with pyroclastics, limestone breccia, and slumped lime- stone with pyroclastics and chert (Smirčić et al., 2020). Basinal deposits continue into the Carnian in the Southern Alps and the Internal Dinarides, whereas shallow water and terrestrial conditions prevail in the External Dinarides (Buser, 1989; Dozet, 2009; Gerčar et al., 2017). In the western Julian Alps, the Eastern and the Northern Dolo- mites, the Buchenstein Formation is followed by the Ladinian Zoppè Sandstone (arkosic turbiditic sandstone; slope fan), Aquatona Formation (pe- lagic limestone, tuff ), Fernazza Formation (vol- canics and volcaniclastics, chaotic breccia), the uppermost Ladinian Wengen Formation (volcan- ic-detritic sediments, gravity f low deposits), and the uppermost Ladinian - Carnian San Cassiano Formation (Gianolla et al., 1998; Neri et al., 2007; Mietto et al., 2020). The latter consists of alter- nating shale, marlstones, marly to pure micritic limestone, oolitic calcarenite, bioclastic and on- colytic calcarenite, and calcirudite. Volcaniclastic 99Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia sandstone is present in various proportions, de- pending on the paleotopography. Mixing of car- bonate and siliciclastic grains is frequent. Sand- stone layers show erosional bases, normal grading, and planar and cross lamination, indicating tur- biditic transport with episodes of debris f low and slumping (Neri et al., 2007). In the proximity of the Cassian platform, the lower boundary of the San Cassiano Formation can be defined based on the lowest occurrence of oolitic calcarenites, whereas elsewhere the boundary with the Wen- gen Formation may be difficult to decide (Neri et al., 2007). The lateral variability within the San Cassiano Formation, depending on the paleoto- pography, is consistent with the lateral variability observed among the sections studied herein. The San Cassiano Formation differs from the Carnian successions from the Slovenian Basin in greater proportion of calcarenites. In the Internal Dinar- ides, the upper Anisian shallow marine carbonates are locally overlain by breccia, tuffite and basalt, and/or the hemipelagic cherty limestone and dis- tal turbiditic cherty limestone of the Kopaonik Formation (Schefer et al., 2010). Drowning of the platform took place in the late Anisian and onward up until the end of the early Ladinian. Sedimenta- tion of the Kopaonik Formation lasted at least into the Norian (Schefer et al., 2010). Finally, a notable terrigenous input characteris- es the upper Julian (Carnian) Tor Formation in the Julian Alps. The Tor Formation overlies peritidal carbonates and consists of siltstone, marly lime- stone and dolostone, micritic limestone, bivalve lumachellas, marlstone, and claystone (De Zanche et al., 2000; Gianolla et al., 2003; Gale et al., 2015). The siliciclastic input is thus notably younger and less pronounced than in the Tolmin Basin. Conclusions The Ladinian – Carnian volcano-sedimenta- ry succession from the Slovenian Basin consists largely of shale, sandstone, and limestone (hem- ipelagic and gravity-f low deposits), with subor- dinate breccia/conglomerate. According to the present data, only the lower part of the Pseudoz- ilja formation comprises lithologically distinct facies assemblage, with a substantial proportion of diabase and tuff. Despite previous suggestions by some authors, the lithological similarities be- tween the upper part of the Pseudozilja formation and the Amphiclina formation documented here- in seem to preclude a distinction between the two formations. Based on the continuous presence of thin-shelled bivalves and radiolarians, the entire succession deposited in an open marine setting. The common occurrence of carbonate gravity-f low deposits, debris breccias, slump and channel structures, suggests the succession deposited on or near continental slope. Channel directions and slump fold-axes suggest slope inclination towards the south and the prevailing transport direction from north to south. As the Ladinian – Carnian succession of the Slovenian Basin is dominated by shale, sandstone, and hemipelagic limestone, it is distinguished from deeper-marine successions of the same age in the Dinarides and in the Julian Nappes of the Southern Alps. Acknowledgements Fieldwork and laboratory work for this research were carried out in the scope of the research project “Sedi- mentological and geochemical research of the “Pseudoz- ilja” and equivalent formations”. Finalization of the pa- per was made possible thanks to research core fundings No. P1-0011 and P1-0195 is co-funded by the Slovenian Research and Innovation Agency. We are thankful to the anonymous reviewers who carefully read the manu- script and provided constructive remarks. 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CC Atribution 4.0 License Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals Izotopska sestava ogljika (δ13C) in dušika (δ15N) petrološko različnih terciarnih lignitov in premogov Tjaša KANDUČ1* & Miloš MARKIČ2 1Department of Environmental Sciences, Jožef Stefan Institute, Jamova cesta 39, SI–1000 Ljubljana, Slovenia; *corresponding author: tjasa.kanduc@ijs.si 2Geological Survey of Slovenia, Dimičeva ulica 14, SI–1000 Ljubljana, Slovenia; e-mail: milos.markic@geo-zs.si Prejeto / Received 9. 2. 2024; Sprejeto / Accepted 3. 5. 2024; Objavljeno na spletu / Published online 11. 6. 2024 Key words: lignite, coal, petrography, C and N isotopic composition, gelification, mineralization Ključne besede: lignit, premog, petrografija, izotopska sestava C in N, gelifikacija, mineralizacija Abstract This study investigates the carbon (δ13Corg) and nitrogen (δ 15N) isotopic composition of tertiary lignites and coals from six sedimentary basins: Velenje, Mura-Zala, and Zasavje in Slovenia; Sokolov in Czech Republic, Barito in Indonesia; and Istria in Croatia. The aim is to investigate the correlation between the fine detrital (fD) component and δ13C and δ15N in Velenje lignite samples. Additionally, we aim to evaluate the biogeochemical processes of organic substances during their deposition in all analyzed samples, calculate their δ13CCO2 values and compare the analyzed values of δ 13C and δ15N to those reported in the literature. Thirty-two samples were analyzed, predominantly from the Velenje ortho-lignite (Pliocene), with additional lignites and coals from the Pannonian to Paleocene epochs for comparison. Carbon isotopic composition (δ13Corg) ranged from -27.9 to -23.6 ‰, and nitrogen isotopic composition (δ 15N) ranged from 1.8 to 7.4 ‰. The fine- detrital lithotypes of the Velenje ortho-lignite exhibited the most negative δ13Corg values due to anaerobic bacterial activity in an intramontane alkaline lake environment inf luenced by the carbonate hinterland. Moreover, gelification processes affected fine-detrital organic matter more than larger wooden pieces. Terbegovci, Hrastnik meta-lignites, and Barito sub-bituminous coal also displayed low δ13Corg values, indicating limited gelification, while variations in the δ 15N values suggested differences in mineralization. The Velenje xylitic lithotypes have higher δ15N values, indicating a more intense mineralization under aerobic conditions. Raša ortho-bituminous coal, deposited in a brackish environment, displayed the highest δ13Corg values and a wide range of δ 15N values due to f luctuating water tables in a paralic carbonate platform environment. The lowest δ15N value was observed in the Sokolov Basin lignite coal, indicating minimal mineralization and low bacterial activity. The isotopic composition of CO2 in air (δ 13Cair), which was calculated using the δ 13C values in lignites and coal, ranged from -8.4 to -3.4 ‰, with Velenje lignite displaying the minimum value and Raša coal showing the maximum value. The determined δ13C and δ15N values of the coal and lignite samples in this research fall within the typical range of world coals. Izvleček Ta raziskava proučuje izotopsko sestavo ogljika in dušika (δ13Corg in δ 15N) terciarnih lignitov in premogov iz šestih sedimentacijskih bazenov: Velenje, Mura-Zala in Zasavje v Sloveniji; Sokolov na Češkem; Barito v Indoneziji; in Istri na Hrvaškem. Cilj je iskati korelacijo med fino detritno (fD) komponento in δ13Corg, δ 15N v velenjskih lignitnih vzorcih ter oceniti biogeokemične procese organske snovi med odlaganjem v vseh analiziranih vzorcih, izračunati δ13CCO2 ter primerjati analizirane vrednosti δ13C in δ15N z objavljeno literaturo. Analiziranih je bilo dvaintrideset vzorcev, večinoma iz Velenjskega orto-lignita (pliocen), za primerjavo pa še ligniti in premogi od panonijske do eocenske starosti. Izotopska sestava ogljika (δ13Corg) vseh vzorcev se je spreminjala od -27,9 do -23,6 ‰, in izotopska sestava dušika (δ 15N) od 1,8 do 7,4 ‰. Fino-detritni litotipi Velenjskega orto-lignita so pokazali najbolj negativne vrednosti δ13Corg zaradi anaerobne bakterijske aktivnosti v intramontanem alkalnem jezerskem okolju pod vplivom karbonatnega zaledja. Procesi gelifikacije bolj vplivajo na drobno-detritno organsko snov kot na večje lesne ostanke. Meta-ligniti iz Terbegovcev in Hrastnika ter Barito sub-bituminozni premog so prav tako pokazali nizke vrednosti δ13Corg, kar kaže na omejeno gelifikacijo. Spremembe v δ15N kažejo na razlike v mineralizaciji. Velenjski ksilitski litotipi so pokazali višjo δ15N, kar kaže na bolj intenzivno mineralizacijo v aerobnih pogojih. Raški orto-bitumenski premog, odložen v brakičnem okolju, je pokazal najvišjo δ13Corg in širok razpon δ15N vrednosti zaradi nihajočih vodnih nivojev v paraličnem karbonatnem platformnem okolju. Najnižja δ15N je bila opažena v lignitnem premogu iz Sokolovskega bazena, kar kaže na minimalno mineralizacijo in nizko bakterijsko aktivnost. Izotopska sestava CO2 v zraku (δ 13Cair), ki je bila izračunana iz δ 13C v lignitih in premogih se je spreminjala od -8,4 do -3,4 ‰, pri čemer je velenjski lignit pokazal najnižjo vrednost, raški premog pa najvišjo. Določene vrednosti δ13C in δ15N vzorcev lignita in premoga v tej raziskavi padejo znotraj razpona svetovnih premogov. GEOLOGIJA 67/1, 105-128, Ljubljana 2024 https://doi.org/10.5474/geologija.2024.006 106 Tjaša KANDUČ & Miloš MARKIČ Introduction Coal, which accounts for 65 % of the world’s to- tal fossil fuel resources, is widely distributed glob- ally and accounts for 40 % of global power genera- tion (Shafiee & Topal, 2009; Hariana et al., 2021). Coal is a sedimentary rocks that has evolved from compressed vegetation, trapped between layers of rocks over millions of years and is combustible. Among geological materials, it is among the most intricate, composed of organic matter, elements (C, H, O, N, S), water, oil (CH), gases (mainly CH4 and CO2), and a variety of minerals (Rađenović, 2006). The initial phase of the coalification pro- cess (e.g. Diessel, 1992) involves the microbial degradation of plant ingredients into peat, occur- ring either aerobically or anaerobically. Subse- quent changes in temperature with depth under overlying strata and pressure modify the physical and chemical characteristics of the sedimentary environment, during which the peat transforms into lignite and higher-ranking coals. Variations in geochemical conditions and the heterogeneity of plant tissues contribute to different coal types (Kirby et al., 2010), which comprise varying pro- portions of macerals (organic components) and inorganic minerals. The primary maceral groups are the huminite to vitrinite, exinite or liptinite, and inertinite groups (Stach et al., 1982; Diessel, 1992; Taylor et al., 1998; Speight, 2013; Flores & Moore, 2024). Stable isotopes play a significant role in pale- oclimate studies, as they are commonly used to track biogeochemical processes, including peatifi- cation and coalification processes (Hoefs, 1987). It is known that photosynthesis leads to an en- richment of light isotopes, namely 12C and 14N, in plants (O’Leary, 1988). The typical value of δ13C for C3 plants is approximately -27 ‰ (expressed relative to the Vienna Peedee Belemnite, VPDB), while for C4 plants like Zea mays, δ13C is around -14 ‰. The range of δ15N in the biosphere varies from -10 ‰ to 10 ‰ (Peterson & Fry, 1987). The δ13C values for most coals fall within the range of -29 to -20 ‰, aligning with that of modern C3 veg- etation, i.e., -34 ‰ to -23 ‰ (Ding et al., 2019). However, during the early stages of organic mat- ter diagenesis, isotopic fractionation occurs due to bacterial activity, leading to an enrichment in the heavier (13C and 15N) isotopes. Numerous studies have been conducted on the δ13C and δ15N values of the coal matrices in different sedimentary basins, and both δ13C and δ15N have been utilized to eval- uate and understand the evolution of ecological environments. For example, δ15N is employed to trace the sources of organic matter and the vege- tation involved in peat formation and to assess the extent of bacterial activity during the peat-form- ing stage (Taylor et al., 1998), while δ13C is used to trace air temperature, humidity, soil moisture, and precipitation rates (Bechtel et al., 2008; Xu et al., 2020; Li et al., 2022; Lin et al., 2022; Masood et al., 2022; Panda et al., 2022). Furthermore, δ13C values can be used to estimate the δ13Cair values of ancient atmospheres (Arens et al., 2000; Gröcke, 2002). In the Velenje Basin, Pezdič et al. (1998) ini- tiated the study of biogeochemical processes of various lithotypes (xylite, detrital lignite, fuzinite) of the ortho-lignite using δ13C analysis. Subse- quent research by (Kanduč et al., 2005; Kanduč et al., 2007; Kanduč et al., 2012) expanded on this work by investigating the Velenje ortho-lignite, as well as other coals such as meta-lignites from Ka- nižarica and Senovo, and plant tissues using both δ13C and δ15N tracers. These studies consistently revealed distinct δ13C and δ15N values among the different lignite lithotypes from the Velenje Ba- sin, indicating variations in biochemical reactions during coalification, specifically gelification re- sulting in 12C enrichment and mineralization pro- cesses leading to 15N enrichment (Kanduč et al., 2005; Kanduč et al., 2012; Kanduč et al., 2018). Kanduč et al. (2018) also conducted a detailed in- vestigation of authigenic mineralization associated with organic matter in lignite from the Velenje Ba- sin, while Bangjun et al. (2019) focused on deter- mining biomarkers in the Velenje lignite samples, which were first studied together with stable car- bon isotope composition to interpret paleo-envi- ronmental conditions and early coalification pro- cesses (Bechtel et al., 2003). A similar study was performed on the Trbovlje (Zasavje) coal by Bech- tel et al. (2004). The isotopic composition of sul- phur (δ34S) and elemental composition of carbon and nitrogen in several Slovenian coals, including Velenje, Trbovlje, Senovo, and Kanižarica, were examined by Šturm et al. (2009), who observed variations between the coal seams and different coal types. These differences were attributed to SO4 2- and Fe2+ availability and microbial activity. The objective of the present study is to isotop- ically characterize (δ13Corg and δ 15N) samples of lignite and coals from six geological basins: Ve- lenje, Mura-Zala, and Zasavje in Slovenia, Sokolov in Czechia, Barito in Indonesia, and Raša (Istria) in Croatia. The primary focus was to search for a correlation between the fine detrital (fD) compo- nent and their δ13C and δ15N values in Velenje lig- nite samples. Further, we determined the extent of bio-geochemical processes, such as gelification 107Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals and mineralization of organic matter. To achieve this, we compared our results with previously published isotopic data on lignites and coals and to the isotopic composition of recent plant samples to elucidate any discrepancies and highlight the deg- radation of organic matter during the coalification process. Additionally, we calculated δ13C values in relation to atmospheric carbon dioxide (δ13CCO2) to determine potential differences in paleo-air among the studied coals. Geological characteristics of sampling locations Sampling locations from six coal-bearing sed- imentary basins (Velenje, Mura-Zala, Zasavje, Sokolov, Barito, and Istria), with basic information on locality, coalification rank, and age are present- ed in Table 1 and Figure 1. Knowing the geological characteristics and paleo-environment of the sampling locations in the separate basins is essential for interpreting the bio- and physicochemical coalification processes within different geological realms. Table 1. Characteristics of studied lignites and coals. Abbreviation of samples (and number of samples analyzed) Lignite / Coal from a basin Locality - seam Coalification Rank Age VL (22) Velenje (Slovenia) Pesje – Velenje seam Ortho-lignite Pliocene TL (2) Mura-Zala (Slovenia) Terbegovci lignite from a borehole. Meta-lignite Pannonian (“Pontian”) HC (1) Zasavje (Slovenia) Laško syncline Hrastnik seam Terezija field Meta-lignite / sub-bitumi- nous coal Oligocene JC (1) Sokolov (Czechia), Josef seam Meta-lignite / sub-bitumi-nous coal Oligocene BC (1) Barito (Indonesia) Barito seam Sub-bituminous coal Miocene RC (5) Istria (Croatia)RC Raša – in-limestone seam Ortho-bituminous coal Paleocene Fig. 1. Sampling locations from the six coal-bearing sedimentary basins in Slovenia, Czechia, Indonesia (Ind.) and Istria. 108 Tjaša KANDUČ & Miloš MARKIČ Velenje ortho-lignite (VL), Velenje basin, N Slovenia The Velenje lignite-bearing basin is a typical intramontane freshwater lacustrine basin formed as a pull-apart basin (Vrabec, 1999) during the Pliocene to Quaternary times. It was created by polyphase dextral strike-slip fault tectonics be- tween the Smrekovec and Šoštanj faults (Fig. 2). The basin contains a sequence of clastic sediments that can reach up to 1000 meters in thickness and host a single lignite seam that is exceptional- ly thick, measuring extremelly, up to 165 meters (Brezigar, 1985). Fig. 2. The Velenje lignite basin: geological map (upper left), lithologic column (upper right), and cross-section (bottom) (Brezigar, 1985). 109Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals According to the literature data, the average calorific value of the lignite, on an as-received basis (based on core data), is 10.7 MJ/kg, with a moisture content of 33.5 % and an ash content of 18.0 % (RCMWRA, 2002; Veber & Dervarič, 2004; Papež, 2019). The sulfur content, on a dry basis (db), varies from around 1.0 % to 5.5 %, with the latter being mainly detected where the lignite seam is close to the carbonate bedrock (Markič & Sachsenhofer, 2010). The Velenje lignite is classi- fied as a typical ortho-lignite in terms of coalifi- cation rank, characterized by approximately 45 % bed moisture (ash-free basis), 62.7–66.4 % carbon content (dry, ash-free basis), 58.3–57.7 % volatile matter (dry, ash-free basis), and the gross calorif- ic value (GCV) ranging from 12.23 to 15.25 MJ/ kg (bed moist, ash-free basis) (Markič & Sachsen- hofer, 2010). The ref lectance (Rm %) of huminite (ulminite B) varies from 0.34 to 0.41 %, suggesting that this lignite can be classified as a meta-lignite. However, this range can also result from optical effects, such as subtle oxidation caused by pro- nounced aerobic bacterial and fungal activity dur- ing peatification and early coalification (Markič & Sachsenhofer, 2010).Fig. 3. Lithologic column of TER-1/03 well. The sampled coal ma- terial is from a depth interval of 141.0–155.5 m; N = number of samples; the whole column is given in Markič & Brenčič (2014). Fig. 4. Geological map of the Zasav- je Basin – Laško Syncline (adapted from Buser, 1978 and Premru, 1983, taken from Bechtel et al. (2004)). Notable is the Hrastnik coal mine in the central-eastern part of the map. 110 Tjaša KANDUČ & Miloš MARKIČ Terbegovci lignite (TL), Mura–Zala Basin, NE Slovenia Based on the gross calorific value on a dry, ash-free basis (GCVdaf b) of 28.137 MJ/kg, the coal material was classified as a humic high-grade me- ta-lignite, similar in rank to the meta-lignites in the Mura Formation formed during the late Pano- nian (Markič et al., 2011). Hrastnik coal (HC), Zasavje Basin, Central Slovenia The E-W trending Laško syncline (Fig. 4) of the Zasavje Basin is about 40 km long and up to 3 km wide, bounded by the Trojane and Litija anticlines to the north and the south, respectively (Kuščer, 1967; Buser, 1978; Premru, 1983; Placer, 1998 and references therein). The lithologies and formations Fig. 5. Above: Schematic lith- ologic column of Tertiary strata in the Zasavje basin – Laško Syncline (modified af- ter Kuščer, 1967). Below left: Zasavje humic coal with an andesitic tuff interlayer (7 cm thick). Below middle: sapro- pelic coal. Below right: sapro- pelic coal with sub-millimetre fragments of lake molluscs (“white dots”). The sample was taken from the humic coal seam. n=1 111Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals above the coal seam are shown in the lithologic column in Figure 5. The average coal grade and calorific value (as received basis) for the k. 34 Terezija polje (Hrast- nik), from which the sample was taken, are as fol- lows: coal moisture 19.7 %, ash yield 33.1 %, S con- tent 4.2 %, and the net calorific value 12.8 MJ/kg (RTH d.o.o., 2013). Using the formula in (Thomas, 1992, p.30), the gross calorific value at the dry, ash-free basis (GCVdaf b) is 30.2 MJ/kg, ranks the Hrastnik coal into the sub-bituminous coalifica- tion rank. This rank is generally consistent with the rank determined by vitrinite ref lectance of 0.5 % Rm, as reported in Bechtel et al. (2004) for the Zasavje-Trbovlje seam. Josef coal (JC), Sokolov Basin, W Czechia Lignites from Czechia are thoroughly described in Pešek (2014). The Nove Sedlo Formation is com- posed of effusive and volcanoclastic rocks, mark- ing the first significant stage of the extension of the Sokolov Basin associated with intense tectonic movements and volcanic activity. The lower part hosts the Josef coal seam, from which the sam- ple was taken (Fig. 6). Its moisture content (as re- ceived basis) ranges between 28 and 43 %, the ash content (dry basis) between 2.6 and 27.3 %, and the sulphur content (dry basis) between 0.5 and 11.8 % (Rojík et al., 2014). Its gross calorific value (dry, ash-free basis) is between 29.1 and 31.5 MJ/ kg, and its ref lectance (Rm %) ranges from 0.3 to 0.45 %. The coal is ranked as a metalignite to sub- bituminous coal (Rojík et al., 2014; p. 134). Barito coal (BC), Barito Basin, Indonesia The Barito Basin is located in South Kaliman- tan (Fig. 1). It is one of the main geological basins in the region, containing abundant coal resourc- es and reserves. Within the basin, the Warukin Formation is among those where coal is present (Fig. 7). The rocks in the Warukin Formation pri- marily comprise sandstones and claystones with coal deposits (Supandi & Hartono, 2020). The coal imported from Indonesia to Slovenia is excavated in the open-cast Pasir Mine, Indonesia’s third largest single mine, operated by the Kideco Jaya Agung Company. The geology of the Pasir Mine is summarized here from the work of Choi et al. (2013) and Supandi and Hartono (2020). The Barito Basin coal from the Pasir Mine is known for its low sulphur content (<0.2 %) and is considered an environmentally friendly coal-energy source due to an ash content of <5 %. The Barito coal in Fig. 6. Stratigraphic scheme of the Upper Oligocene of the Sokolov Basin fill, (after Rojík et al., 2014); n = number of samples taken from the Josef Coal Seam. (The Stare Sedlo Fm below the Nove Sedlo Fm is not shown). Fig. 7. Regional stratigraph- ic column of the Barito Basin showing the coal seams in the Warukin Formation (mod- ifed after Supandi & Hartono, 2020); n = number of samples taken. 112 Tjaša KANDUČ & Miloš MARKIČ Southern Kalimantan occurs in several widely de- veloped beds up to 10 m thick and is sub-bitumi- nous (Thomas, 1992; Internet 2). Raša Coal (RC), Istrian Basin, Croatia The Istrian coal mines in the eastern part of the Istrian Peninsula in Croatia’s Northern Adriat- ic Sea region (Fig. 1) held the largest economically viable anthracite coal deposits in Croatia from the 18 th century until 1999. One distinctive character- istic of the Raša coal is its high organic sulfur con- tent, reaching up to 14 % (Medunić et al., 2016). During the initial phase of coalification, known as humification, organic sulphur compounds are gen- erated as plant debris decomposes due to bacterial activity. Hamrla (1960) determined that the Raša coals were formed under anaerobic conditions. The substantial organic sulphur content in these coals is attributed to the bacterial reduction of marine sulphates, which became incorporated into the or- ganic matrix (Medunić et al., 2016). Raša coal is classified as an ortho-bituminous coal (Table 1) with a gross calorific value (dry, ash-free basis) of 34.3 MJ/kg and a vitrinite re- f lectance (Rr %) of 0.64 (Hamrla, 1959; Hamrla, 1985). Sampling and methods Thirty-two lignite and coal samples from six diverse sedimentary basins were collected for this study (Fig. 1). Detailed data, e.g., coordinates of origin with mine sampling locations and sampling date, are presented in the data repository (Kanduč et al., 2023). The coal samples were obtained from various locations, including underground mining areas (Velenje lignite – VL, Hrastnik coal – HC, Raša coal – RC), open-pit mines (Josef coal – JC), and boreholes (Terbegovci lignite – TL). Twenty-two samples (Table 1) of the ortho-lig- nite from Velenje were collected during the mac- ro-petrographic logging of three nearly horizontal boreholes from the Pesje and Preloge excavation fields: JPK-52 (+2°) (excavation field B-65/A, Pesje), JGM-55 (+10°) (excavation field B K. -130 Preloge, south wing), and JPK-60 (+10°) (exca- vation field F K.-65 Pesje). All these cores were collected in the southern central and lower part of the lignite seam (Fig. 2). The boreholes passed through intervals with different lithotype com- positions, which have a more significant inf lu- ence on the isotopic composition than with seam depth (Kanduč et al., 2005; Markič & Sachsen- hofer, 2010). The Terbegovci meta-lignite samples (TL) were taken from a depth of 141.0–155.5 m as a composite sample of coal cuttings during the drilling of the TER-1/03 water supply well (Fig. 3), while a single bulk sample of meta-lig- nite/sub-bituminous coal from the Hrastnik mine was collected just before the mine ceased opera- tion in 2012. A sample from the Josef meta-lig- nite/sub-bituminous coal seam was also collected (Table 1), and the Thermal-Heat Power Station Ljubljana - Termoelektrarna Toplarna Ljubljana provided a coal sample identif ied as a sub-bitu- minous coal from the Barito Basin (Pasir Mine) in Indonesia. Additionally, f ive samples (Table 1) of ortho-bituminous coal from Raša were collected from different seams of unique petrologic compo- sition (Hamrla, 1959; Medunić et al., 2016). 37 Once grand, now forgotten: what do we know about the superhigh-organic-sulphur Raša coal The Mining-Geology-Petroleum Engineering Bulletin, 2016, pp. 27-45 © The Author(s), DOI: 10.17794/rgn.2016.3.3 Figure 7. Stratigraphic column of the Istrian basin Lithostratigraphy has been given after Velić et al, 2015. Fig. 8. Regional stratigraphic column from Medunić 2016, after Velić et al., 2015, n = number of samples taken. n=5 113Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals Macropetrographic description of the Velenje ortho-lignite Macropetrographic classification of the litho- type heterogeneity of the Velenje ortho-lignite has been defined and described in detail by Markič et al. (2001) and Markič & Sachsenhofer (2010). For its macropetrographic description and com- position, a concept of lithotype components was introduced (Fig. 9). The classification is somewhat broader than the “official” classification by the (ICCP, 1993). Microscopic descriptions of samples (VL3 and VL5, Table 2a) were prepared by crushing the ma- terial (<2 mm), embedding it in epoxy resin, sub- jecting it to vacuum, drying, and then creating pol- ished blocks of size 2.5×2.5 cm. The investigation was conducted using Zeiss Opto Axiophot conven- tional optical microscopy in polarised ref lected light under normal atmospheric conditions, and the results were documented photographically. Isotopic composition of organic carbon (δ13Corg) and nitrogen (δ15Nbulk) The stable isotopic composition of organic car- bon (δ13Corg.) and nitrogen (δ 15Nbulk) in different lignite and coal lithotypes was analyzed using the Europa 20–20 isotope-ratio mass spectrometer connected to an ANCA-SL preparation module. To prepare the lignite and coal samples, they were ini- tially homogenized by grinding in an agate mortar. For δ13Corg analysis, the samples were treated with 3M HCl at 60 °C overnight to eliminate carbonates. The remaining residues were washed with distilled water, dried, and homogenized. The organic fraction was filtered through a GF/F filter, and chloride ions were removed with triple washing with distilled water. The residue was then dried at 60–70 °C. Approximately 1–2 mg of the residue was used for δ13Corg measurements. Approximately 8 mg of pow- dered lignite and coal were used for δ15N analyses with no pretreatment. The carbon and nitrogen iso- topic compositions were determined by combusting the samples in sealed tin capsules in an oxidation column using pure oxygen at 1000 °C. The gener- ated products went throw a reduction column filled with Cu at 600 °C and then separated on a chroma- tographic column. IAEA CH-3 (δ13C = -24.724 ‰ ±0.041 ‰) and CH-6 (δ13C = -10.449 ‰ ±0.033 ‰) reference materials were employed to convert the analytical results to the VPDB scale. IAEA N-1 (δ15N = +0.4 ‰ ±0.2 ‰) and IAEA N-2 (δ15N = +20.41 ‰ ±0.12 ‰) were used as reference mate- rials to relate the analytical results to AIR (atmos- pheric nitrogen) (Coplen, 1996). The reproducibility of the samples was ±0.2 ‰ for carbon isotopes and ±0.3 ‰ for nitrogen isotopes. The results are ex- pressed in the standard δ notation (in per mil, ‰) as the deviation of the sample (sp) from the stand- ard (st) according to the following equation (Brand et al., 2014): Fig. 9. Basic concept of macropetrographic classification for the Velenje ortho-lignite (Markič et al., 2001; Markič & Sachsenhofer, 2010) using a concept of lithotype components and the Uden scale for dimension limits. 114 Tjaša KANDUČ & Miloš MARKIČ Fig. 10. Lithotype classification is employed in macro-petrographic core logging of the Velenje ortho-lignite. JGM-55 borehole (excavation field B k.-130) (this study) (see appendix) is an example of petrographic well-logging. 115Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals δyX(‰) = (R sp/Rst-1)*1000 (1) Where yX is carbon (13C) or nitrogen (15N), and R the 13C/12C or 15N/14N, respectively. The δ13C of air (atmospheric CO2) was then cal- culated using the equations proposed by Arens et al. (2000) (equation 2) and Gröcke (2002) (equa- tion 3). Gröcke, 2002 suggested that the carbon iso- topic composition of ancient CO2 can be estimat- ed using the δ13C value of fossil organic matter. In this study, it is assumed that the samples with δ13C values from -27 ‰ to -22 ‰ were derived from terrestrial/freshwater C3 plants (δ13Cplant) and that in Equ. 2, any carbon isotope fractionation during plant metabolism is similar to that of modern C3 plants and that the primary control on plant C iso- topes is the carbon isotopic composition of atmos- pheric CO2 (δ 13Cair). δ13Cair = (δ 13Cplant+18.67)/(1.10) (2) δ13Cair = δ 13Cplant + 20.22 (3) Results The results of the macropetrographic classifi- cation and the associated δ13Corg and δ 15N values of lignites and coals and calculated δ13Cair accord- ing to equations (2) and (3) from the six selected locations are presented in Tables 2a and 2b. The isotopic data (δ13Corg. and δ 15N), the macropetro- graphic composition data obtained in this study, and previously published data have been uploaded to a public repository (Kanduč et al., 2023). Table 2a. Results of macropetrographic composition of the Velenje lignite (this study) according to decreasing share of xylite (X) and increas- ing share of fine detrite (fD), with associated δ13Corg and δ 15N values, δ13Cair values calculated after Arens et al. (2000) and Gröcke (2002), and ash yields from Hann et al. (2020). Ash yields were analyzed as composites of two to five samples with similar petrographic composition. Sample/Location Macropetrographic composition δ13Corg. (‰) δ15N (‰) A ft er A re n s et a l. (2 0 0 0) A ft er G rö ck e (2 0 0 2) F ro m H an n e t al . ( 2 0 2 0) Interval (m) X (%) dX (%) xD (%) fD (%) δ13Cair (‰) Ash yield (%) VL2, Velenje JPK 60 21.5-21.9 95 5 -25.3 +5.6 -6.4 -5.5 2.69 VL1, Velenje JPK 52 16.2-13.3 90 10 -26.6 +3.4 -7.2 -6.4 VL3, Velenje JGM 55 7.0-7.2 85 15 -25.7 +7.4 -6.4 -5.5 4.93 VL4, Velenje JGM 55 9.6-9.9 85 15 -25.7 +4.0 -6.0 -5.1 VL15, Velenje JPK 52 24.75-24.9 70 30 -25.5 +3.5 -6.2 -5.3 4.45 VL16, Velenje JPK 60 8.95-9.15 70 5 25 -25.0 +4.8 -5.8 -4.8 VL13, Velenje JPK 60 5.5-5.85 20 10 30 40 -26.2 +4.4 -6.8 -6.0 9.91VL12, Velenje JPK 52 22.8-22.95 40 15 45 -26.6 +3.9 -7.2 -6.4 VL14, Velenje JPK 60 11.5-11.7 35 15 50 -25.5 +4.6 -6.2 -5.3 VL19, Velenje JPK 60 6.6-6.75 10 5 10 75 -27.2 +3.0 -7.8 -7.0 9.81 VL20, Velenje JPK 60 15.8-16.0 10 5 10 75 -26.5 +4.5 -7.1 -6.3 VL18, Velenje JPK 60 5.85-6.15 5 15 80 -27.0 +3.6 -7.6 -6.8 9.83 VL17, Velenje JGM 55 1.35-1.55 5 10 85 -27.3 +3.5 -7.8 -7.1 VL6, Velenje JPK 52 20.35-20.55 10 90 -27.9 +2.6 -8.4 -7.7 9.63 VL8, Velenje JPK 60 19.65-19.8 10 90 -27.4 +4.1 -7.9 -7.2 VL9, Velenje JPK 60 20.6-21.0 5 95 -26.9 +2.7 -7.5 -6.7 VL5, Velenje JPK 52 17.7-17.8 5 95 -27.7 +2.7 -8.2 -7.5 VL7, Velenje JPK 60 10.0-10.5 5 95 -27.2 +3.0 -7.8 -7.0 VL10, Velenje JPK 52 21.4-21.55 5 95 -27.1 +5.3 -7.7 -6.9 14.73 VL11, Velenje JGM 55 7.2-7.4 100 -26.9 +3.5 -7.5 -6.7 VL21, Velenje JGM 55 19.5-19.7 Geloxylite (X65 G35) -27.5 +3.6 -8.0 -7.3 VL22, Velenje JPK 60 2.5-2.7 5 55min -27.5 +3.7 -8.0 -7.3 23.30 X – xylite, dX – detro-xylite, XD – xylo-detrite, fD – fine detrite 116 Tjaša KANDUČ & Miloš MARKIČ The Velenje lignite comprises xylitic compo- nents of varying dimensions, shapes, packing, and orientations within a fine detrital matrix. These lithotype components can be categorized as fine detrite (fD), xylo-detrite (XD), and xylites of dif- ferent sizes (X, XX, XXX) (Fig. 9). Fusite (F) often occurs as incrustations over xylite. Fusite is ob- tained from the so-called fusinitization pathway (Diessel, 1992), which proceeds under relatively oxygen-enriched conditions. Fusinitization may cause a loss of organic matter and relative enrich- ment in residual mineral matter (mineralization process). The mineral components typically con- sist of various forms of calcite (Markič & Sachsen- hofer, 2010; Kanduč et al., 2018), consistent with the classification of this lignite as Ca-rich lignite (Markič & Sachsenhofer, 2010). Also, organic com- ponents may exhibit different degrees of gelifica- tion, classified as weak (G), moderate (GG), and strong gelification (GGG). In the Velenje lignite, huminite macerals (textinite, texto-ulminite, ulm- inite, attrinite, and densinite) largely predominate, with a share in a total maceral composition rang- ing between 85 and 95 % by volume, while liptinite and inertinite macerals are highly subordinated (Markič & Sachsenhofer, 1997, 2010). Xylite refers to fossilized wood pieces larger than 64 mm, i.e., larger than an average borehole-core diameter. In contrast, the detrite consists of fine plant detritus that underwent a coalification pro- cess known as biochemical gelification more read- ily and rapidly compared to xylites (Diessel, 1992; Stach et al., 1982; Taylor et al., 1998), resulting in structural homogeneity of the lignite. The color of detrite ranges from homogeneously dark brown (poorly gelified) to black (if strongly gelified). De- tro-xylite and xylo-detrite are xylitic pieces within a fine-detrital matrix. In the case of detro-xylite, the woody pieces are larger than 32 mm, while in xylo-detrite, they are <32 mm (Figs. 9 and 10). Other lignites and coals in this study are clas- sified by rank (ECE-UN,1998), for example, or- tho-lignite, meta-lignite, sub-bituminous coal, bituminous coal and ortho-bitumnous coal (Table 1), and in terms of well-known hard-coal litho- types: vitrain, clarain, durain and fusain (Stach et al., 1982; Diessel, 1992; Taylor et al., 1998; Flores, 2014). Table 2b. Results of macropetrographic composition analysis: TL – Terbegovci lignite (n = 2), HC – Hrastnik coal (n = 1), JC – Josef coal (n = 1), BC – Barito coal (n = 1), RC – Raša coal (n = 5) with associated δ13Corg and δ 15N values, and δ13Cair values as calculated after Arens et al. (2000) and Gröcke (2002). Sample/Location Coalification rank and lithotypes All are humic lignites and coals δ13Corg. (‰) δ15N (‰) δ13Cair (‰) After (Arens et al., 2000) δ13Cair (‰) After (Gröcke, 2002) TL – Terbegovci lignite, Terbegovci (TER-1/03), Mura Zala basin, NE Slovenia Meta-lignite, high grade (high grade; <10 % ash db) -27.0 +4.4 -7.6 -6.8 TL – Terbegovci lignite, TER- 1/03, Mura Zala basin, NE Slovenia Meta-lignite, high grade (high grade; <10 % ash db) -27.1 +4.2 -7.7 -6.9 HC- Hrastnik coal Terezija po- lje - Hrastnik, Laško syncline, Central Slovenia Meta-lignite- Durain -27.2 +4.3 -7.8 -7.0 JC – Josef coal, Sokolov Basin, Czech Republic Meta lignite - Durain -25.6 +1.8 -6.3 -5.4 BC – Barito coal, Barito Basin, Indonesia Sub-bituminous coal -27.5 +2.7 -8.0 -7.3 RC – Raša coal, Istrian Basin, Croatia Ortho-bituminous coal – Vitrain -23.6 +3.2 -4.5 -3.4 RC – Raša coal, Istrian Basin, Croatia Ortho-bituminous coal – Vitrain -23.7 +4.6 -4.6 -3.5 RC – Raša coal, Istrian Basin, Croatia Ortho-bituminous coal – Vitrain -23.9 +3.8 -4.8 -3.7 RC – Raša coal, Istrian Basin, Croatia Ortho-bituminous coal – Vitrain -24.0 +5.5 -4.8 -3.8 RC – Raša coal, Istrian Basin, Croatia Ortho-bituminous coal – Vitrain -24.0 +2.9 -4.8 -3.8 117Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals Discussion Relation between xylite, detro-xylite, xylo- detrite and fine-detrite components and associated δ13Corg, and δ 15N in the Velenje lignite samples Among the twenty-two samples of the Velen- je ortho-lignite (Table 2a), the following samples with distinct lithotype compositions can be dis- tinguished: six samples of xylite-rich lignite (X >70 %), eleven samples of fine-detrital lignite (fD >75 %) and three samples with a xylite-rich com- position (X + dX + xD) 50–60 %, fD 40–55 %, one sample of highly gelified xylite, and one min- eral-rich fine detrital sample. In order to look for a possible relationship between fD (fine-detrital component) and δ13Corg. in the Velenje lignite sam- ples, we applied the Mann-Whitney U test. How- ever, no significant difference was identified at the 0.05 significance level. The relationship between fD and δ13Corg. (Fig. 11), using Spearman’s non-par- ametric coefficient is -0.74. The Spearman’s cor- relations (p<0.05) for Velenje lignite samples re- vealed the following correlations: X (%) vs fD (%) -0.97, X+dX (%) vs δ13C (‰) 0.66 and δ15N (‰) vs δ13C (‰) 0.65. dX component is not significantly correlated with any parameter at a p<0.05. Samples of geloxylite (VL 21) and samples en- riched with mineral matter (VL 22) are not includ- ed in Fig. 11, while two xylite samples with δ13Corg. of -25.7 ‰ and fD 15 % overlap. As observed from Figure 11, xylite-rich lignites (X + dX + xD) ≥50 % vs fD ≤50 % are characterized by δ13Corg values from -26.6 to -25.0 ‰, while those of fine-detri- tal lignite (fD ≥75 %) are mostly between -27.9 and -26.9 ‰, with one exception with a δ13Corg of -26.5 ‰. The ash content (Table 2a) in the fine-detrital lignite is higher than in xylitic lignite. Also, the xylite samples (X >70 %) have ash content from 2.69 to 4.45 % and δ13Corg. from -26.6 to -25.0 ‰, while samples enriched with detrital component (fD >40 %) have ash contents from 9.91 to 14.73 % (Table 2a) and are enriched with light 12C isotope. The higher ash content for fD (Table 2a) results from water f low inf lux, with the lake water be- ing subsequently alkaline, promoting gelification, which is discussed in continuation. Biogeochemical processes reflected by δ13Corg. and δ15N in lignites and coals Mineralization, i.e. microbial degradation of organic matter (enrichment with 13C and 15N iso- tope) and gelification processes (enrichment with -28.5 -28.0 -27.5 -27.0 -26.5 -26.0 -25.5 -25.0 -24.5 0 10 20 30 40 50 60 70 80 90 100 dd1 3 C or g. (‰ ) fD (%) Fine detrital lignite Xylitic lignite R2 = -0.74 Fig. 11. δ13Corg values vs the share of fine detrital (fD) component of the investigated Velenje lignite samples. 118 Tjaša KANDUČ & Miloš MARKIČ the light 12C isotope) are best expressed in the Ve- lenje lignite samples (Table 2a, Fig. 12). The lower δ13Corg values (≤-27.9 ‰) in the Velenje ortho-lig- nite indicate a high degree of gelification and are common in fine-detrital matrix. In comparison, the δ15N values (≤7.4 ‰) indicate intense miner- alization. The δ15N value for liptinite is common- ly more positive than that for vitrinite, followed by inertinite (Rimmer et al., 2006). Fine organ- ic terrestrial detritus (giving fine detrital lignite) was accumulated in open-water environments of the inner and upper parts of the initial peatland, whereas higher bush and forest vegetation (giving xylite-rich lignite) occupied the periphery (Markič & Sachsenhofer, 2010). Several groups indicating one or both processes (mineralization and biochemical gelification) can be distinguished (Fig. 12): lower values of δ13Corg (<-26.9 ‰) are characteristic for the freshwater f ine-detrital Velenje ortho-lignite formed in topo- geneous mire, as well as for meta-lignite from Ter- begovci and Hrastnik, and sub-bituminous coal from Barito formed in a raised swamp. The lowest δ13Corg values (Fig. 12) are observed in the fine-detrital lignite, which is more affect- ed by the gelification process than the xylite frag- ments, especially in an alkaline environment where there is significant anaerobic bacterial activity, as in Velenje (Pliocene), Hrastnik (Zasavje Basin - Oligocene) and Terbegovci (Mura-Zala Basin – up- per Pannonian). Environments with strong gelifi- cation are also characterized by low mineralization, as indicated by low δ13C values. However, as the proportion of xylite components increases, δ13Corg and δ15N values increase due to weaker effects of biochemical gelification and stronger effects of mineralization (Fig. 12). This can be explained by the presence of more aerobic conditions, the sub- dued oxidation of organic components, and the ac- tivity of aerobic bacteria, which result in a relative loss of organic matter and an increase in mineral content. A distinctly notable pattern with a δ15N value of 7.4 ‰ is observed in Velenje xylite (Fig. 12), which is attributed to the highest degree of mineralization. The lowest δ15N value (1.8 ‰) was analyzed in the meta-lignite/sub-bituminous coal from the Josef seam (Oligocene) in the Sokolov Basin. The coal from the Josef seam is a predomi- nantly “detritus-rich,” even “sapropelic-rich,” coal formed from accumulated organic matter in a low drained swamp environment (“peat bog”) with oc- casional input of tuffaceous material (Rojík, P. in Pešek et al., 2014, p.101). Such an environment is characterized by negligible mineralization and low 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 -28.5 -28 -27.5 -27 -26.5 -26 -25.5 -25 -24.5 -24 -23.5 -23 δ1 5 N (‰ ) δ13Corg. (‰) VL-detrite VL-geloxylite VL-detroxylite VL-detrite with mineral matter VL-xylite TL HC JC BC RC BIOCHEMICAL GELIFICATION M IN ER AL IZ AT IO N (d eg ra da tio n of o rg an ic m at te r) Josef coal VL xylite Fig. 12. δ15N vs δ13Corg for Velenje lignite – VL, Raša coal – RC, Hrastnik coal - HC, Jožef coal - JC, Barito coal - BC and Terbegovci lignite - TL. Degradation of organic matter enriches coal samples with 13C and 15N isotopes; different degrees of biochemical gelification (weak, moderate, strong) enriches lignite with 12C and is the most expressed in Velenje lignite samples. 119Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals gelification, most likely due to a relatively acidic paleoenvironment. A different isotopic composition occurs in the ortho-bituminous (black) coal from Raša (Istrian Basin - Paleocene). This coal formed in a paralic environment with a carbonate hinterland and the probable inf luence of brackish or marine waters. It shows a narrow range of relatively higher δ13Corg values, from -24.0 to -23.6 ‰, and a broader range of δ15N values, from 2.9 to 5.5 ‰. Higher δ13Corg values, from -24.0 to -23.6 ‰, could be attributed to the contribution of organic matter of marine or- igin. A f luctuating water table (alternating trans- gressions and regressions) in a paralic carbonate platform environment (e.g., tidal f lats, lagoons, deltas, mixing of nonmarine and marine sedi- ments) most probably caused by significant chang- es in mineralization, is evidenced by a wide range of δ15N values. Bacterial activity was also likely present in the brackish paralic carbonate-rich en- vironment. However, they did not lead to intense gelification of the organic matter; instead, bacteri- al degradation led to different mineralization. The lowest δ15N value (1.8 ‰) was measured in the meta-lignite/sub-bituminous coal from the Sokolov basin, indicating the lowest mineraliza- tion of organic matter among all the samples ex- amined and a low degree of bacterial activity. The highest measured δ15N value (7.4 ‰) of “pure” xylite (i.e., < 5 % ash yield, Table 2a) in the Velenje ortho-lignite indicates pronounced mineralization (Fig.12). Microscopic inspection did not prove the effect of fuzinitization (Fig. 13a). However, cell lumena of textinites are empty implying exposure to air and thus the degradation (mineralization) of organic matter primarily filling cell lumena. The volume content of the textinite (highly prevailing), texto-ulminite and ulminite macerals (Fig. 13a) together is 75 %, corresponding to the of mac- ro-petrographic estimates (X 85 %, Table 2a). The Velenje fine-detrital ortho-lignite (VL) composed of >90 % of the fD component (Table 2a) Fig. 13. Micro-petrograph- ic appearance of two contrast lithotypes of Velenje lignite: a) sample VL-3 - Xylinite (X) with phlobaphynite (Ph) highly prevails in xylite-rich ortho-lig- nite; analyzed ash yield is <5 wt. % and b) sample VL-5 – Ditrinite to densinite (D-DS) highly prevails in fine detrital ortho-lignite; analysed ash yield is <10 wt. %. U is ulminite; dc are desiccation cracks. 120 Tjaša KANDUČ & Miloš MARKIČ has δ13Corg from -27.9 to -26.9 ‰ (avg.: -27.3 ‰) and δ15N mostly from 2.6 to 3.5 ‰ (extremes: 4.1 ‰ and 5.3 ‰, respectively) (avg.: 3.5 ‰), both indicating considerable gelification (Table 2a and Figs. 12 and 13b). Strongly gelified samples from previous studies (excavation field -50/C, Velenje Basin) had δ13C around -28.0 ‰ with the lowest δ13Corg value of even -28.7 ‰, (Fig. 14) (strong gelification) and δ15N of 2 ‰, which indicates low mineralization (Kanduč et al., 2018; Kanduč et al., 2023). Considering δ13C values, the precursor plants are C3 plants with values from -33 ‰ to -22 ‰ in all investigated coals (Figs. 12 and 14). Recent plants collected around the Velenje Basin (Kanduč et al., 2005; Kanduč et al., 2012; Kanduč et al., 2023), such as trunks (δ13C = -28.0 ‰, δ15N = -3.3 ‰), conifer needles (δ13C = -27.0 ‰, δ15N = -3.6 ‰), grass (δ13C = -31.1 ‰, δ15N = -3.7 ‰), and bushes (δ13C = -25.0 ‰, δ15N = -2.3 ‰), ex- hibit more negative δ15N values compared to lig- nites and coals (Fig. 14). Recent plants in the Sava River Basin, Slovenia, have on average δ13C val- ues of -31.6 ‰ and δ15N values of 0.2 ‰ (Kan- duč et al., 2007; Kanduč et al., 2023). The δ13C and δ15N values of parent organic matter and coalifi- cation processes depend on the source of organic matter (bushes, grass, trunks, and conifer nee- dles) and local meteorological conditions (Liu et al., 2020). Calculated δ13C values of atmospheric CO2 (δ13CCO2) The variation in δ13C of the plants is primarily controlled by the atmospheric CO2 isotopic com- position (δ13CCO2) rather than the concentration of CO2 in the atmosphere (Arens et al., 2000). There- fore, the δ13C values of coal can be used to esti- mate the ancient δ13CCO2 values (Arens et al., 2000; Gröcke, 2002). The Eqs. (2) and (3) proposed by (Arens et al.,2000) and (Gröcke, 2002), respective- ly, have been used for estimating ancient δ13C CO2 using the carbon isotopic composition of organic matter (δ13Cplant). This estimation assumes that the carbon isotopic fractionation of plants with atmos- pheric CO2 is a single-step process (Gröcke, 2002). Enrichment with 13C in atmospheric CO2 could be related to the burial of more terrestrial plant de- bris due to rising sea levels (Xu et al., 2020). Dies- sel (2010) also demonstrated that the late Carbon- iferous-early Permian was characterized by low pCO2 and more positive δ 13Cair values, followed by an increasing atmospheric oxygen content in the mid-early Permian. -10 -8 -6 -4 -2 0 2 4 6 8 10 -35 -33 -31 -29 -27 -25 -23 -21 δ1 5 N (‰ ) δ13Corg. (‰) VL-detrite, this study VL-geloxylit, this study VL - detroxylite, this study VL-detrite with mineral matter VL-xylite, this study TL, this study HC, this study JC, this study BC, this study RC, this study C3 plants, Sava River watershed trunk, conifer needles, grass, bush poorly gelified detrital lignite moderate gelified deitrital lignite strongly gelified detrital lignite xylite, Velenje Basin fuzinite, Velenje Basin Senovo coal Kanižarica coal Lignites and Coals C3 plants Fontinalis sp. grass trunk bush conifer needles Fig. 14. δ15N versus δ13Corg.: plants (terrestrial and aquatic) (Kanduč et al., 2005; Kanduč et al., 2007), and lignites and coals from this and previous studies (Šlejkovec & Kanduč, 2005; Kanduč et al., 2005, Kanduč et al., 2018). 121Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals In this study from selected coals, the δ13CCO2 value ranges from -3.4 to -8.4 ‰ (Tables 2a, b) based on Eqs. (2) and (3) for all selected coal loca- tions. The calculated δ13CCO2 of coals in our study are in the broader range of values published by Panda et al. (2022) for coals of Permian age (-5.6 to -2.3 ‰). Interestingly, Raša coals of Paleogene age have δ13CCO2 ranging from -4.8 to -3.4 ‰, while a broader range is observed in geologically the youngest Pliocene Velenje lignite (from -5.8 to -8.4 ‰ after (Arens et al., 2000). The global aver- age δ13CCO2 value of modern atmospheric CO2 was reported as -8.4 ‰ in 2015 (Graven et al., 2020). Results from one year of monitoring (January 2011 to November 2011) from nine locations in the Ve- lenje basin around thermo power plant Šoštanj in- dicate δ13CCO2 of atmospheric CO2 in the range from -18.0 to -6.4 ‰ with an average value of -11.7 ‰ (Kanduč, 2015). This average value shows enrich- ment with 12C compared to δ13Cair from the Plio- cene Velenje lignite formation. The pre-industrial global average was estimated for 1850 at -6.6 ‰ (Graven et al., 2020). Table 3. The δ13C values of peat (Alaska), lignites and coals from this study and of different world coals. Country Age δ13C (‰) Rank Reference Alaska Late galicial-E. Holocene from -28 to -34 Peat Panda et al., 2022 and references therein China Pliocene from -28.4 to -25.4 Lignite Panda et al., 2022 and references therein Velenje, Slovenia Pliocene from -25.3 to -27.0 Lignite Panda et al., 2022 and references therein Austria Miocene from -27.4 to -23.8 Lignite Panda et al., 2022 and references therein Poland Miocene from -27.2 to -24.6 Lignite Panda et al., 2022 and references therein Germany Miocene from -27.3 to -24.6 Lignite Panda et al., 2022 and references therein Australia Miocene from -27.8 to -24.9 Lignite Panda et al., 2022 and references therein Australia Oligocene from -26.4 to -24.2 Panda et al., 2022 and references therein Australia Eocene from -26.4 to -23.6 Panda et al., 2022 and references therein India Eocene from -28.7 to -25.3 Lignite Panda et al., 2022 and references therein India Palaeocene from -30.7 to -25.5 Lignite Panda et al., 2022 and references therein Mongolia L. Cretaceous from -23.5 to -21.3 Lignite Panda et al., 2022 and references therein Australia Jurassic from -25.2 to -20.9 Sub-bituminous Panda et al., 2022 and references therein South-Africa Permian from -25.0 to -23.2 Bituminous Panda et al., 2022 and references therein North China Permian from -25.3 to -22.7 Sub-bituminous to bituminous Panda et al., 2022 and references therein Australia Permian from -26.6 to -21.9 Panda et al., 2022 and references therein India Permian from -24.2 to -21.0 Bituminous Panda et al., 2022 and references therein China Late Carboniferous from -24.3 to -23.1 Bituminous Panda et al., 2022 and references therein USA Carboniferous from -25.1 to -23.5 Bituminous Panda et al., 2022 and references therein India Permian from -23.8 to -21.7 Sub-bituminous to bituminous Panda et al., 2022 and references therein Velenje, Slovenia Pliocene from -27.4 to -22.6 Ortho - lignite Pezdič et al., 1998 Velenje, Slovenia Pliocene from -28.7 to -23.0 Ortho - lignite Kanduč et al., 2005, Kanduč et al., 2018Kanduč et al., 2023 Kanižarica Miocene from -29.9 to -24.9 Brown coal Kanduč et al., 2018 Senovo Oligocene from -25.6 to -23.9 Brown coal Kanduč et al., 2018 Velenje, Slovenia Pliocene from -27.9 to -25.0 Ortho - lignite This study Hrastnik Oligocene -27.2 Bitumnious coal – durain This study TER-1/03, NE Slovenia Upper Pannonian from -27.0 to -27.1 Meta-lignite- durain This study Raša, Croatia Paleocene from -24.0 to -23.6 Bituminous–vi-train This study Sokolov, Czeck Republic Oligocene -25.6 Brown coal This study Pasir mine, Indonesia Miocene -27.5 Humic, high-grade meta–lignite This study 122 Tjaša KANDUČ & Miloš MARKIČ Isotopic data in this study gathered with worldwide coals The δ13C and δ15N values in coals analyzed in this study and previous studies and those for world- wide coals are presented in Tables 3 and 4. Data from the coalfields analyzed in our study fall with- in the range of isotopic values of coals worldwide, i.e., from -30.7 to -20.9 ‰. Characteristic δ13C val- ues for Paleozoic coals range from -25.7 to -20.2 ‰ (Panda et al., 2022 and references therein). Higher δ13C values (up to -23.6 ‰) are also observed for Raša coals of Miocene age (Table 3). The δ13Corg values of Velenje lignites fall with- in the characteristic range for worldwide lignite, while a broader range (up to 7.4 ‰) is observed for δ15N (Table 2a). The carbon isotopic composition (δ13Ccoal, VPDB) of coal samples from the Taiyu- an and Shanxi formations of Quinshi and North China-Boloiwan basins ranges from -25.3 ‰ to -22.7 ‰, with an average of -23.7 ‰. The average δ13Ccoal value is -23.6 ‰ in the late Carboniferous, -23.4 ‰ in the early Permian, and -20.5 ‰ in the mid-early Permian (Xu et al., 2020). Early Permian coals in the southern North China-Boloiwan Ba- sin to the east were isotopically significantly more negative, with a δ13Corg value of -25.2 ‰ (Table 3), likely due to regional aridity changes. Geologically younger lignites (Paleocene to Pliocene age) have more negative δ13C compared to geologically older higher rank coals (Late Carboniferous – Late Cre- taceous) (Table 3). There is also disagreement regarding the rela- tionship between δ15N and coal rank, with several authors reporting a positive correlation between δ15N and coal rank (Zheng et al., 2015), while oth- ers suggest that δ15N values are largely independ- ent of maturation (Boudou et al., 2008). The δ15N of the examined peats range from -1.4 to 1.6 ‰, while lignites exhibit values from -1.4 to 1.8 ‰ and coals from India show values from -2.8 to 5.0 ‰. These values indicate that each material preserves its unique organic matter source signature. More- over, the highest δ15N values found in Cenozoic lig- nites compared to Cenozoic sub-bituminous coal suggest regional climatic variation. Furthermore, Gondwana anthracites display elevated δ15N val- ues from 1.3 to 5.0 ‰, attributed to the tectonic inf luence of the Himalayan orogeny (Ganguly et al., 2023). In addition, our study observes no re- lationship between coal rank and δ15N values; Pli- ocene lignites from the Velenje Basin can also be enriched with 15N with δ15N up to 7.4 ‰ (Table 4). Conclusion This study examined various ortho-lignite samples from the Velenje Basin, having homoge- neous fine-detrital and heterogeneous xylite-rich lithotypes. We also analyzed higher-rank coals for Table 4. The δ15N values of lignites and coals from this study and from different world coals. Country δ15N (‰) Rank Reference China from -6 to -10 Lignite to antracite Panda et al., 2022 and references therein Canada from -0.2 to 1.4 NA Panda et al., 2022 and references therein Russia from 1.86 to 4.35 NA Panda et al., 2022 and references therein SE-Asia (Indonesia, Malaysia, Phillippines) from 0.38 to 2.32 NA Panda et al., 2022 and references therein Europe from 3.5 to 6.3 Lignite to anthracite Panda et al., 2022 and references therein Australia from 0.3 to 3.7 Lignite to semi-anthracite Panda et al., 2022 and references therein USA from 2.1 to 5.35 Bituminous to anthracite Panda et al., 2022 and references therein Germany from 2.7 to 3.72 Anthracite Panda et al., 2022 and references therein India from 1.07 to 3.44 Bituminous to anthracite Panda et al., 2022 and references therein India from 0.6 to 3.4 Sub-bituminous to high volatile bituminous Panda et al., 2022 and references therein Velenje, Slovenia from 1.8 to 4.6 Ortho – lignite Kanduč et al., 2005, Kanduč et al., 2018 Kanižarica from 5.2 to 7.4 Brown coal Kanduč et al., 2018 Senovo from 3.9 to 6.0 Brown coal Kanduč et al., 2018 Velenje, Slovenia from 2.6 to 7.4 Ortho – lignite This study Hrastnik, Slovenia 4.3 Bitumnious coal-vitrain This study TER-1/03, NE Slovenia from 4.2 to 4.4 Meta-lignite-durain This study Raša, Croatia from 2.9 to 5.5 Meta-lignite-durain This study Sokolov, Czech Republic 1.8 Brown coal This study Pasir mine, Indonesia 2.7 Humic, high-grade meta-lignite This study 123Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals comparison, such as meta-lignites, meta-lignites/ sub-bituminous coals, sub-bituminous coals and ortho-bituminous coals. The coals under study were formed in different paleoenvironments and deposited in environments inf luenced by seawa- ter, as seen in the case of the Raša ortho-bitumi- nous coal and Barito sub-bituminous coal. They were also found in freshwater lake environments, as exemplified by the Velenje ortho-lignite, Hrast- nik, and Josef seam meta-lignite/sub-bituminous coals, as well as the Terbegovci meta-lignite and span different geological ages, including the Pale- ocene (RC), Upper Oligocene (HC, JC), Upper Mi- ocene (JC), upper Pannonian (TL) and Pliocene (VL). During the processes of peatification and coali- f ication, bacterial activity differed in oxic and anoxic conditions across all the investigated sed- imentary coal basins. Moreover, the coals were deposited in open waters, bush moors, and for- est swamps. These variations are ref lected in the δ13Corg and δ 15N of coals we investigated. The wide range of δ13Corg (from -27.9 to -23.6 ‰) and δ 15N (from 1.8 to 7.4 ‰) values observed in the six dif- ferent coals indicates different intensities of bioge- ochemical processes and depositional conditions, including the source of vegetation, humification, bacterial activity, and redox conditions. Gelifica- tion, which leads to enrichment with 12C and min- eralization, which leads to enrichment in 15N, are most evident in the Velenje ortho-lignite samples. The detrital lignite sample exhibited the lowest δ13C value of -27.9 ‰, whereas the highest value of -23.6 ‰ was measured in Raša coal. The δ15N val- ues of the coal samples also fall within the typical worldwide range, which is between -6.0 to 5.4 ‰. Only the Raša sample with a value of 5.5 ‰ and two xylite samples with δ15N values of 5.5 ‰ and 7.4 ‰ from Velenje deviate from the worldwide values, indicating higher mineralization. In previous stud- ies, the highest microbial degradation, indicating high activity, was observed in the Raša coal (Pale- ocene) and the Velenje xylite samples (Pliocene), with the highest δ13C values of -23.6 ‰. Among all the analyzed samples, gelification was characteris- tic of Velenje lignite samples, with δ13Corg ranging up to -27.9 ‰ and the lowest (-29.9 ‰) in the Ka- nižarica sample in previous studies. Similar δ13C and δ15N values were only detected in Hrastnik coal (durain maceral type) and Terbegovci lignite samples, suggesting they were deposited in fresh- water environments (open water) with similar pre- cursor plants. Both the δ13C and δ15N parameters indicate that C3 plants are the precursor plants in all the investigated coal locations. The precursor plant material and microbial degradation played crucial roles during peatification and coalification, inf luencing both δ13C and δ15N values. The calculated δ13CCO2 values range from -8.4 ‰ to -3.4 ‰, which is more positive in all the coal sedimentary basins compared to the δ13CCO2 of modern atmospheric CO2, reported for the year 2015 (-8.4 ‰, global average). In our study, we can conclude that biogeochemical processes in the coal basin mask the paleoclimate. However, fur- ther systematic studies based on macropetrologi- cal and microscopic analysis and using elemental ratios and biomarkers combined with δ13Corg and δ15N data are needed to understand better the bi- ogeochemical processes involved in coalification. Acknowledgements We thank the Slovenian Research Agency and In- novation (ARIS) for project funding L2 – 4066: Petrol- ogy of brown coals mined and used in Slovenia, gases in them and their gas-sorption properties (2011-2014) and program fundings: P1-0143 and P1-0025. 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CC Atribution 4.0 License Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain Tektonika in gravitacijski pojavi, drugi del: Trnovsko- banjško-šentviška degradirana uravnava Ladislav PLACER1*, Tomislav POPIT2 & Igor RIŽNAR3 1Geološki zavod Slovenije, Dimičeva ul. 14, SI–1000 Ljubljana, Slovenija; *corresponding author: ladislav.placer@telemach.net 2Univerza v Ljubljani, Naravoslovnotehniška fakulteta, Oddelek za geologijo, Aškerčeva 12, SI-1000 Ljubljana, Slovenija; e-mail: tomi.popit@ntf.uni-lj.si 3Geološke ekspertize Igor Rižnar s. p., SI-1000 Ljubljana, Slovenija; e-mail: igor.riznar@telemach.net Prejeto / Received 22. 3. 2024; Sprejeto / Accepted 29. 5. 2024; Objavljeno na spletu / Published online 11. 6. 2024 Key words: External Dinarides NW, geomorphology, gravitational phenomena, karst plains, degraded karst plains, Idrija fault Ključne besede: Zunanji Dinaridi NW del, geomorfologija, gravitacijski pojavi, kraške uravnave, degradirane kraške uravnave, Idrijski prelom Abstract The article describes the recent conditions at the Paleogene thrust contact between the External Dinaric Thrust Belt composed of carbonate rocks and the External Dinaric Imbricate Belt composed of f lysch rocks, geographically, between the Trnovski gozd (Trnovski gozd plateau) and the Vipava Valley at the northwestern end of the Dinarides. Fossil and recent gravity-related phenomena that indicate the uplift of the southwestern edge of the External Dinaric Thrust Belt and the larger complex in the hinterland are found there. However, these phenomena are not related to the reactivated Paleogene thrust tectonics, but to the Neogene-recent underthrusting as a consequence of the Microadria (Adriatic Microplate) movement towards the Dinarides. Only arguments for these processes are presented in this article. Izvleček V članku so opisane recentne razmere na paleogenskem narivnem stiku med Zunanjedinarskim narivnim pasom iz karbonatnih kamnin in Zunanjedinarskim naluskanim pasom iz f lišnih kamnin. Geografsko med Trnovskim gozdom (Trnovska planota) in Vipavsko dolino na severozahodnem koncu Dinaridov. Tu najdemo fosilne in recentne gravitacijske pojave, ki kažejo na dviganje jugozahodnega obrobja Zunanjedinarskega narivnega pasu in večjega kompleksa v zaledju, vendar to ni povezano z reaktivirano paleogensko narivno tektoniko, temveč z neogensko-recentnimi procesi podrivanja, ki so posledica pomikanja Mikroadrije (Jadranska mikroplošča) proti Dinaridom. V članku so predstavljene le posledice teh procesov. GEOLOGIJA 67/1, 129-156, Ljubljana 2024 https://doi.org/10.5474/geologija.2024.007 Introduction The Microadria (Adriatic microplate) is moving towards the Dinarides, which northwestern part is described by Blašković (1991); Weber et al. (2006; 2010); Placer et al. (2010); Vrabec et al. (2018). It has not been precisely determined when the con- vergence process began, but in general we assume that it started in the Middle Miocene and con- tinues today, which is why we use the term Neo- gene-recent activity of the Adriatic Microplate. Its characteristics have not yet been sufficiently stud- ied, but the result of this process is the narrowing of the Dinarides, which is kinematically different from the narrowing of the Dinarides in the Paleo- Uvod Mikroadrija (Jadranska mikroplošča) se po- mika proti Dinaridom, za njen severovzhodni del so o tem pisali Blašković (1991); Weber et al. (2006; 2010); Placer et al. (2010); Vrabec et al. (2018). Kdaj se je pričel proces približevanja ni natančneje ugotovljeno, v splošnem pa menimo, da v srednjem miocenu in traja še danes, zato uporabljamo termin neogensko-recentna dejav- nost Jadranske mikroplošče. Njene značilnosti še niso dovolj raziskane, posledica tega procesa pa je oženje Dinaridov, ki se kinematsko razli- kuje od oženja le-teh v paleogenu, v zaključnem obdobju nastajanja krovne zgradbe. Razlikuje se 130 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR K V A R N E R LJUBLJANAUDINE TRIESTE 0 50 km I S T R A Fig. 2 SAF IF RIJEKA S O U T H E R N A L P S D I N A R I D E S A D R I A A D R I A T I C S E A SF KF T H S 1 2 3 4 5 6 7 8 9 10 11 12 T IF 131Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain gene, in the final period of the formation of the nappe structure. It differs mainly in that, in addi- tion to successive deformations, new plicative and disjunctive structures also emerged. The Istran block is located between the Sesl- jan and Kvarner Faults, an integral part of the Mi- croadria which, in contrast to the other blocks of the Microadria, is noticeably pushed towards the northeast. Its visible part is Istra (Fig. 1). As a re- sult, an extensive Istra Pushed Area was formed in the Dinaric hinterland of the block, in which longi- tudinal morphostructural objects are laterally bent towards the northeast (Placer et al., 2010; 2023). This situation is illustrated by the morphostruc- tural trajectory in the figure. The two branches of the Dinaric thrust boundary in Istra are related by the Črni Kal Anomaly, which is substantiated in the article by Placer et al. (2023, p. 18–30). This article discusses the laterally bent Paleo- gene thrust boundary between the External Di- naric Imbricated Belt, composed predominantly of f lysch rocks, and the External Dinaric Thrust Belt, which is composed mostly of carbonate rocks. Ex- tensive, sub-recent and recent gravity-related phe- nomena have developed here, which significantly affect the geomorphology of the landscape (Komac & Ribičič, 2008; Kocjančič et al., 2019; Placer et al., 2021a). The described conditions are particu- larly pronounced on the northeastern part of the Vipava Valley beneath the carbonate brims of the Trnovski gozd and Nanos plateaus (Popit et al., 2022), where fossil gravity bodies are stacked in several consecutive levels, and the recent ones are spread out over them; such are e.g. the recent large Slano Blato and Razdrto planar landslides (Fig. 2). The conditions therefore show that the External Dinaric Thrust Belt is being uplifted in this area predvsem v tem, da so poleg nasledstvenih defor- macij nastale tudi nove plikativne in disjunktivne strukture. Sestavni del Mikroadrije je istrski blok med Sesljanskim in Kvarnerskim prelomom, ki je na- sproti drugim blokom Mikroadrije opazno potis- njen proti severovzhodu. Njegov vidni del je Istra (sl. 1). Zaradi tega je v dinarskem zaledju bloka nastalo obsežno istrsko potisno območje v kate- rem so longitudinalni morfostrukturni objekti bočno usločeni proti severovzhodu (Placer et al., 2010; 2023). To stanje ponazarja morfostruktur- na trajektorija na sliki. Dva kraka narivne meje Dinaridov v Istri povezuje črnokalska anomalija, ki je utemeljena v članku Placer et al. (2023, str. 17-30). V tem članku obravnavamo bočno usločeno narivno mejo paleogenske starosti med Zunanje- dinarskim naluskanim pasom, pretežno iz f lišnih kamnin in Zunanjedinarskim narivnim pasom pretežno iz karbonatnih kamnin. Tu so se raz- vili obsežni subrecentni in recentni gravitacijski pojavi, ki pomembno vplivajo na geomorfologijo krajine (Komac & Ribičič, 2008; Kocjančič et al., 2019; Placer et al., 2021a). Opisane razmere so posebej izrazite na severovzhodnem obrobju Vi- pavske doline pod karbonatnimi obronki planot Trnovski gozd in Nanos (Popit et al., 2022), kjer so fosilna gravitacijska telesa naložena v več nad- stropjih, recentna pa se prožijo preko njih; taka sta npr. velika recentna planarna plazova Slano blato in Razdrto (sl. 2). Razmere torej kažejo, da se enota Zunanjedinarskega narivnega pasu na tem območju dviga (Mihael Ribičič, ustna izjava 2010), kar povzroča nestabilnost pobočij, vendar dviganje ni posledica reaktivacije krovnega nariva Zunanjedinarskega narivnega pasu paleogenske Fig. 1. Structural sketch of the northeastern margin of Microadria. Compiled from: Geological map of Slovenia 1:250 000 (ed. Buser, S. 2009); Geological map of the Friuli Venezia Giulia 1:150 000 (ed. Giovanni Battista Carulli, 2006); Placer et al. (2021; 2023). Sl. 1. Strukturna skica severovzhodnega obrobja Mikroadrije. Sestavljeno po predlogah: Geološka karta Slovenije 1:250 000 (ured. Buser, S. 2009); Carta geologica del Friuli Venezia Giulia 1:150 000 (ured. Giovanni Battista Carulli, 2006); Placer et al. (2021; 2023). 1 Southern Alps / Južne Alpe. 2 External Dinaric Thrust Belt. Front part of thrust unit: T – Trnovo Nappe, H – Hrušica Nappe, S – Snežnik Nappe / Zunanjedinarski narivni pas. Čelni del krovne enote: T – Trnovski pokrov, H – Hrušiški pokrov, S – Snežniški pokrov 3 External Dinaric Imbricate Belt / Zunanjedinarski naluskani pas 4 Adria Microplate (Microadria) / Jadranska mikroplošča (Mikroadrija) 5 Thrust boundary of Southern Alps; thrust fault related to the dynamics of the Southern Alps / narivna mejna Južnih Alp; nariv povezan z dinamiko Južnih Alp 6 Thrust boundary of Dinarides / narivna meja Dinaridov 7 Boundary of the External Dinaric Imbricate Belt / meja Zunanjedinarskega narivnega pasu 8 Boundary of the nappe unit within the External Dinaric Thrust Belt / meja krovne enote znotraj Zunanjedinarskega narivnega pasu 9 Subvertical fault: SAF – Sava Fault, IF – Idrija Fault, SF – Sistiana Fault, KF – Kvarner Fault / subvertikalni prelom: SAF – Savski prelom, IF – Idrijski prelom, SF – Sesljanski prelom, KF – Kvarnerski prelom 10 Črni Kal Anomaly (Placer et al., 2023, pg. 17–30) / črnokalska anomalija (Placer et al., 2023, str. 17–30) 11 Area of large gravitational phenomena / območje velikih gravitacijskih pojavov 12 Morphostructural trajectory / morfostrukturna trajektorija 132 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR (Mihael Ribičič, oral statement 2010), which in- troduces instability into the slopes. However, the uplift is not the result of the reactivation of the Paleogene nappe thrust of the External Dinaric Thrust Belt, but the Neogene-recent activity of the Adriatic Microplate. Paleogene overthrusts in this starosti, temveč neogensko-recentne dejavnosti Jadranske mikroplošče. Paleogenski krovni na- rivi so v tem delu Dinaridov v smeri narivanja subhorizontalni in rahlo undirani (Placer et al., 2021a, str. 47; 2023, sl. 11), regionalno pa blago tonejo proti severozahodu. Fig. 8A Fig. 3, 6 Fig. 4, 11 SF P1 P1’ H T T T T/H T/H H S 1 2 3 4 5 6 7 8 9 10 11 12 13 T IF P1 P1’ TOLMIN IDRIJA NOVA GORICA Livek 0 10 km 2 1 K R A S 1 a a e c e b b dB a n j š i c e T r n o v s k i g o z d V i p a v s k a d o l i n a Š e n t v i š k ap l a n o t a N a n o s IF L iv šk a d ol ina 133Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain Geomorfološka stopnja med Trnovskim goz- dom z Nanosom iz karbonatnih kamnin v Zuna- njedinarskem narivnem pasu in Vipavsko dolino iz f lišnih kamnin v Zunanjedinarskem naluska- nem pasu bi lahko nastala tudi samo zaradi hi- trejše denudacije f liša, vendar so bili pri karti- ranju trase avtoceste po Vipavski dolini pod Nanosom in Trnovskim gozdom odkriti nedvou- mni znaki reverzne tektonike, ki kažejo na podri- vanje (neobjavljeno). Pomembno je tudi, da je več etaž gravitacijskih pojavov lažje razložiti s tek- tonskim dviganjem kot z denudacijo in da nasto- pa geomorfološka stopnja tudi tam, kjer sta obe omenjeni krovni enoti zgrajeni iz f lišnih kamnin (območje trenutnega kartiranja severozahodno od Vipavske doline). Kot strukturni model recentnega dogajanja na meji med Zunanjedinarskim naluskanim pasom in Zunanjedinarskim narivnim pasom v Vipa- vski dolini služi dogajanje na meji med avtohto- nom Istre in Zunanjedinarskin naluskanim pa- som, kjer so ob neogensko-recentnih podrivnih reverznih prelomih paleogenske narivne ploskve antiformno usločene (Placer et al., 2023, sl. 7). Zdi se, da stopničasta zgradba Dinaridov ni povezana samo s paleogensko krovno zgradbo, temveč tudi z neogensko-recentnimi podrivnimi reverznimi prelomi. To opažajo tudi Korbar et al. (2020) na območju Kvarnerja. Longitudinalni desnozmični prelomi Dinaridov imajo pri tem manjši pomen, pomembnejši so le nekateri, npr. Idrijski prelom, ki smo ga zato tudi vključili v članek. V tem članku ni opisan strukturni mehanizem neogensko-recentnega dviganja Zunanjedinar- skega narivnega pasu nad Zunanjedinarski nalu- skani pas v Vipavski dolini, temveč je obdelana le geomorfologija dvignjenih planot nad Vipavsko part of the Dinarides are subhorizontal and slight- ly undulating in the direction of thrusting (Placer et al., 2021a, p. 47; 2023, fig. 11), and regionally dipping gently to the northwest. The geomorphological step between Trnovski gozd and Nanos composed of carbonate rocks in the External Dinaric Thrust Belt and Vipava Val- ley composed of f lysch rocks in the External Di- naric Imbricate Belt could also have been created only due to a faster denudation of f lysch, howev- er, during the mapping of the route of the high- way along the Vipava Valley beneath Nanos and Trnovski gozd unequivocal signs of reverse tec- tonics indicating subduction (unpublished) were found. It is also important that several etages of gravity phenomena can be more easily explained by tectonic uplift than by denudation, and that a geomorphological step occurs also where both of the mentioned nappe units are composed of f lysch rocks (the area of the ongoing mapping northwest of the Vipava Valley). The events on the boundary between the Istra Autochton and the External Dinaric Imbricated Belt, where Paleogene thrust planes are antiformal- ly folded along the Neogene-recent underthrusting reverse faults (Placer et al., 2023, Fig. 7) serve as a structural model of the recent events on the bound- ary between the External Dinaric Imbricated Belt and the External Dinaric Thrust Belt in the Vipava Valley. The stepped structure of the Dinarides ap- pears to be related not only to the Paleogene nappe structure, but also to Neogene-recent underthrust reverse faults. This is also observed by Korbar et al. (2020) in the Kvarner area. Longitudinal right lateral strike-slip faults of the Dinarides are less important, only some are more important, e.g. the Idrija Fault, which it is included it in the article. Fig. 2. Major karst plains on the External Dinaric Thrust Belt and External Dinaric Imbricate Belt. Sl. 2. Večje kraške uravnave na Zunanjedinarskem narivnem in Zunanjedinarskem naluskanem pasu. 1 Southern Alps / Južne Alpe 2 External Dinaric Thrust Belt: T – Trnovo Nappe, H – Hrušica Nappe, S – Snežnik Nappe, T/H – area of the interjacent nappe slices between Trnovo Nappe and Hrušica Nappe (Placer, 1981, fig. 9) / Zunanjedinarski narivni pas: T – Trnovski pokrov, H – Hrušiški pokrov, S – Snežniški pokrov, T/H – območje vmesnih krovnih lusk med Trnovskim in Hrušiškim pokrovom (Placer, 1981, sl. 9) 3 External Dinaric Imbricate Belt / Zunanjedinarski naluskni pas 4 Microadria / Mikroadrija 5 Thrust boundary of the Southern Alps / narivna meja Južnih Alp 6 Thrust boundary of the Dinarides / narivna meja Dinaridov 7 Boundary of the External Dinaric Imbricate Belt / meja Zunanjedinarskega narivnega pasu 8 Boundary of the nappe unit within the External Dinaric Thrust Belt / meja krovne enote znotraj Zunanjedinarskega narivnega pasu 9 Important subvertical fault: IF – Idrija Fault, SF – Sistiana Fault / pomembnejši subvertikalni prelom: IF – Idrijski prelom, SF – Sesl- janski prelom 10 Larger karst plain: a – Aurisina Classical Karst Region, b – Doberdo del Lago, Kostanjevica, and Komen Classical Karst Region, c – Voglarska planota (Voglarji plateau), d – southeastern part of Banjšice (Banjšice plateau), e – eastern part of Šentviška planota (Šentviška Gora plateau) / večja kraška uravnava: a – Nabrežinski Kras, b – Doberdobski, Kostanjeviški in Komenski Kras, c – Voglarska planota, d – jugovzhodni del Banjške planote ali Banjšic, e – vzhodni del Šentviške planote 11 Active planar landslide: 1 – Slano blato, 2 - Razdrto / dejavni planarni plaz: 1 – Slano blato, 2 – Razdrto 12 Profile Nanos (hamlet) - Strane (village) / profil Nanos (zaselek) - Strane (vas) 13 Recording location of fig. 5A / stojišče snemanja sl. 5A 134 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR dolino. Dvig Trnovskega gozda, Banjšic in Šentviške planote se odraža v posebnostih njiho- ve geomorfologije, ta se ne odraža samo v gra- vitacijskih pojavih, temveč, poleg drugega, tudi v intenzivnosti korozivne degradacije kraških uravnav na Zunanjedinarskem narivnem pasu, v tem primeru na Voglarski planoti na severozaho- dnem delu Trnovskega gozda, na jugovzhodnem delu Banjške planote ali Banjšic in na vzhodnem delu Šentviške planote. Pojav korozivne degra- dacije omenjenih uravnav izpeljujemo iz predpo- stavke, da so nastale na nižji nadmorski višini od današnje. Povečana stopnja korozije je posledica ostrejših klimatskih razmer, kar se najlepše opa- zi, ko obravnavane uravnane dele Zunanjedinar- skega narivnega pasu (c, d, e) primerjamo z urav- nanim Krasom, ki leži na nižji nadmorski višini (a, b) (sl. 2). Trnovski gozd in Banjško planoto razmeju- je suha dolina Čepovanski dol, po Dierks et al. (2021) pradol. Slednja je od Šentviške planote lo- čena z Idrijskim prelomom ter ob njem dvignjena za okoli 200 m. Dviganje Trnovskega gozda in Banjške plano- te na današnji nivo se kaže že v samem obstoju Čepovanskega dola, ki ni mogel nastati na da- našnji nadmorski v išini, ker nima hidrografske- ga zaledja. Uravnano območje Trnovskega gozda in Banj- šic sta Stepišnik in Ferk (2024, str. 12–13, 17–18) opredelila kot korozivni kraški ravnik, ki naj bi nastal v času pred dvigom Trnovskega gozda. Enako je o dvigu menil že Habič (1968). V našem članku podajamo geološko-strukturni pogled na kraške uravnave Trnovskega gozda, Banjšic in Šentviške planote, ki potrjuje osnovne geografske ugotovitve, hkrati pa kaže na možnost, da je ime- lo uravnano ozemlje ob svojem nastanku bistveno večji obseg od današnjega. Gravitacijski pojavi Kvartarni gravitacijski pojavi so na seve- rovzhodnem robu Vipavske doline razmeroma dobro obdelani, dosedanje raziskave so pokazale, da je zgradba in geneza pobočnih sedimentov na tem območju izredno kompleksna. Pod čelom pa- leogenskega narivnega roba se nahajajo obsežne akumulacije pobočnih sedimentov, ki so nastali z različnimi mehanizmi transporta in sedimen- tacijskimi procesi (Popit in Košir, 2003; Popit et al., 2013; Popit, 2016). Poleg regionalnih geolo- ških razmer, na mesta pojavljanja in vrsto poboč- nih procesov neposredno vplivajo tudi krajevni strukturni, litološki, hidrološki in geokemični pogoji. This article does not describe the structural mechanism of the Neogene-recent uplift of the External Dinaric Thrust Belt above the External Dinaric Imbricated Belt in the Vipava Valley, only the geomorphology of the raised plateaus above the Vipava Valley is covered. The elevation of the Trnovski gozd, Banjšice and Šentviška Gora pla- teau is ref lected in the peculiarities of their geo- morphology. This is not ref lected only in the grav- itational, but also in the intensity of the corrosive degradation of the karstic plains on the External Dinaric Thrust Belt – in this case on the Voglar- ji plateau in the northwestern part of the Trnovs- ki gozd, in the southeastern part of the Banjšice plateau or Banjšice, and on the eastern part of the Šentviška Gora plateau. The phenomenon of cor- rosive degradation of the above-mentioned settle- ments is derived from the assumption that they were formed at a lower altitude than today. The increased corrosion is the result of harsher cli- matic conditions, which is most apparent when we compare the leveled parts of the External Dinaric Thrust Belt (c, d, e) with the leveled Karst, which lies at a lower altitude (a, b) (Fig. 2). The Trnovski gozd and Banjšice plateaus are delimited by the Čepovan dry valley, a pradol ac- cording to Diercks et al. (2021). The latter is sepa- rated from the Šentviška Gora plateau by the Idrija Fault and was uplifted by about 200 m along the length of it. The uplift of the Trnovski gozd and the Ban- jšice plateaus up to today’s level is already evident in the very existence of the Čepovan dry valley, which could not have been formed at today’s alti- tude because it does not have a hydrographic hin- terland. Stepišnik and Ferk (2023, p. 12–13, 17–18) defined the leveled area of the Trnovski gozd and Banjšice plateaus as a corrosive karst plain, which was thought to have been formed before the up- lift of the Trnovski gozd plateau. Habič (1968) already thought the same about the uplift. In our article, we present a geological-structural view of the Trnovski gozd, Banjšice, and Šentviška Gora plateaus, which confirms some basic geographical findings but at the same time points to the possi- bility that the levelled area extended significantly further at the time of its formation than it does today. Gravitational phenomena Quaternary gravity-related phenomena are rel- atively well studied on the northeastern edge of the Vipava Valley, and research so far has shown that the structure and genesis of slope sediments 135Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain Kvartarni pobočni sedimenti, ki so odloženi pod čelom narivnega roba se v najvišjih delih po- bočja pojavljajo v obliki meliščnih zaplat in pah- ljač. Ti so vezani na prevoje med višje ležečimi strmimi karbonatnimi stenami in položnejšim f lišnim pobočjem pod njimi. Melišča obsega- jo precejšnje območje in predstavljajo glavni vir karbonatnega grušča, ki se nadalje z različnimi mehanizmi transporta in sedimentacijskimi pro- cesi odlaga nižje po neprepustnem pobočju. V nižjih delih pobočja so odložena številna manjša in velika sedimentna telesa in bloki kvartarnih pobočnih sedimentov mestoma sprijetih v poboč- no brečo. Variabilnost kvartarnih sedimentov v posameznih sedimentnih telesih je glede na geo- loško zgradbo ozemlja izredno velika. Izvor ma- teriala predstavljata dva glavna litološka različ- ka: sediment sestavljen iz siliciklastičnih f lišnih kamnin (peščenjak, meljevec, laporovec in mulje- vec) iz f lišne podlage in karbonatni sediment iz karbonatne krovnine v zaledju. Na podlagi dveh litoloških različkov bi pričakovali, da bo sestava in zgradba kvartarnih sedimentov razmeroma enostavna. Po dosedanjih raziskavah pa se je v večini detajlno preiskanih profilov na območju Rebrnic pod Nanosom (Popit et al., 2013) in pla- zu Selo (Košir & Popit, 2002; Popit & Košir, 2003; Verbovšek et al., 2017) izkazala izjemna strati- grafska raznolikost in lateralna spremenljivost. Znotraj splazelih mas je bilo evidentiranih več iz- razito plastnatih sedimentov, ki kažejo na več faz sedimentacije oziroma dogodkov. Če se osredotočimo na območje med Ajdovšči- no in Novo Gorico (sl. 3), po velikosti in obliki močno izstopa 10 km2 velik kompleksni plaz Selo, po Koširju et al. (2015) imenovan podorni tok ve- likega dosega (ang. long runout rock avalanche). Plaz Selo meri približno 4,5km v dolžino, razdalja od odlomnega roba do največjega dosega plazu v dolini pa 5,8 km. Povprečna debelina sedimenta je ocenjena na 19 m, največja izmerjena debelina sedimenta v osrednjem delu pa 56 m (Popit & Ko- šir, 2003; Košir et al, 2015). Volumen plazu, ki je bil ocenjen s pomočjo terenskega dela, radarskega profiliranja in GIS-a, znaša 190 × 106 m3 (Ver- bovšek et. al., 2017). Poleg manjših in večjih sedimentnih teles pahljačastih in jezičastih oblik se na pobočjih na celotnem severnem robu severovzhodnega dela Vipavske doline pogosto pojavljajo tudi planarne izravnave karbonatnih breč, nastale kot posledica velikih rotacijskih plazov, in posamezni večji ali manjši karbonatni bloki nastali z rotacijsko-tran- slacijskimi zdrsi. Na podlagi plastnatosti breče na posameznih delih blokov lahko prepoznamo, in this area is extremely complex. Extensive ac- cumulations of slope sediments formed by various transport mechanisms and depositional process- es (Popit in Košir, 2003; Popit et al., 2013; Popit, 2016) are present beneath the front of the Pale- ogene thrust margin. In addition to regional ge- ological conditions, local structural, lithological, hydrological, and geochemical conditions also di- rectly inf luence the places of occurrence and type of slope processes. Quaternary slope sediments deposited below the thrust front margin appear in the highest parts of the slope in the form of scree patches and fans. These are related to the passes between the higher lying steep carbonate walls and the gentler f lysch slope below them. The scree deposits cover a con- siderable area and are the main source of carbon- ate gravels, which is deposited further down the impermeable slope by various transport mecha- nisms and depositional processes. Numerous larg- er and smaller sedimentary bodies and blocks of Quaternary slope sediments cemented into slope breccia are deposited in the lower parts of the slope. The variability of Quaternary sediments in individual sedimentary bodies is extremely large, considering the geological structure of the territo- ry. The origin of the material is represented by two main lithological differences: sediment consisting of siliciclastic f lysch rocks (sandstone, siltstone, marl, and mudstone) from the f lysch base and car- bonate sediment from the carbonate hanging wall in the hinterland. Based on two lithological differ- ences, the composition and structure of Quater- nary sediments would be expected to be relatively simple. According to previous research, most of the profiles investigated in detail in the Rebrnice area beneath Mt. Nanos (Popit et al., 2013) and the Selo landslide (Košir & Popit, 2002; Popit & Košir, 2003; Verbovšek et al., 2017) revealed extraordi- nary stratigraphic variability and lateral diversity. Several distinctly layered sediments were record- ed within the landslide masses, indicating several phases of sedimentation or events. If we focus on the area between Ajdovščina and Nova Gorica (Fig. 3), the 10 km2 complex Selo landslide stands out in terms of size and shape, according to Košir et al. (2015) and is described as a long runout rock avalanche. The Selo landslide measures approximately 4.5 km in length, with the distance from the crown to the toe end meas- uring 5.8 km. The average sediment thickness is estimated at 19 m, and the maximum measured sediment thickness in the central part is 56 m (Popit & Košir, 2003; Košir et al., 2015). The vol- ume of the landslide, estimated with the help of 136 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR field work, GPR profiling, and GIS, is 190 × 106 m3 (Verbovšek et. al., 2017). In addition to smaller and larger sedimentary fan- and tongue-shaped bodies, planar levelings of carbonate breccias, formed as a result of large ro- tational landslides, and individual larger or small- er carbonate blocks formed by rotational-transla- tional landslides occur often on the slopes of the entire northern edge of the northeastern part of the Vipava Valley. Based on the layering of the breccia in individual parts of the blocks, we can recognize that the blocks rotated up to 60° towards the slope. Such an example occurs in the hinterland of the Šumljak landslide in Rebrnice (Popit, 2017). The leveled surface is developed mainly in the central parts of the planar surfaces, while steep margins appear on the outer parts of the levelings, which represent the main broken edges of the sedimen- tary bodies. These sedimentary bodies, especially in the upper part of the slope, were formed as a re- sult of the remobilization of material from the out- er parts of large rotational landslides, where the material was transported lower down the slope in the form of rock avalanches (Popit, 2017). In addi- tion to planar levelings, individual carbonate part- ly-brecciated gravity blocks are exposed on the slopes in large numbers in the wider vicinity of Lo- kavec, but towards Šempeter they become smaller and less numerous. The exceptional amount and frequency of the occurrence of slope processes is indicated by e.g. the area around Ajdovščina, where there are many large sedimentary bodies along the edge of the Vipava Valley, e.g. the Podrta Gora and Gradiška Gmajna fossil landslides (Popit et al., 2022) and many large gravity (collapsing) carbonate blocks. Based on preliminary research by Placer et al. (2008), and later by Kocjančič et al. (2019), 10 carbonate gravity blocks. The re- sults of the measurements showed that the lengths of the block movements along the slope ranged from 80 m to as much as 1,950 m (Kocjančič et al., 2019). The layered carbonate blocks changed their strike and dip when moving relative to the carbonate layers of the source area. Differences in the incidence of carbonate layers of the source area and carbonate blocks range from 4° to 59°. Larger gravity blocks that appear northwest of Lokavec are Zasod and Školj Sv. Pavla nad Vrtovinom (Ver- bovšek et al., 2019), Zasod pri plazu Selo, Kucl- ji nad Osekom, Vitovski hrib above the village of Vitovlje and many smaller translational gravity blocks (Fig. 6). To the northwest, the occurrence of carbonate blocks decreases considerably, and by the Lijak spring they are practically non-existent. da so bloki rotirali tudi do 60° proti pobočju. Tak primer nastopa v zaledju plazu Šumljak na Rebr- nicah (Popit, 2017). Izravnana površina je razvita predvsem v osrednjih delih planarnih površin, na zunanjih delih izravnav pa se pojavljajo strmi ro- bovi, ki predstavljajo glavne odlomne robove se- dimentnih teles. Ta sedimentna telesa, predvsem v zgornjem delu pobočja, so nastala kot posledica remobilizacije materiala z zunanjih delov velikih rotacijskih plazov, kjer se je material nato v obliki kamninskih plazov transportiral nižje po pobočju (Popit, 2017). Poleg planarnih izravnav so na po- bočjih močno izpostavljeni posamezni karbonat- ni, deloma brečirani, gravitacijski bloki, ki se v velikem številu pojavljajo v širši okolici Lokavca, proti Šempetru pa jih je na pobočju vse manj tako po velikosti kot po njihovi številčnosti. Na izje- mno količino in pogostnost pojavljanja pobočnih procesov kaže npr. območje v okolici Ajdovščine, kjer so vzdolž roba vipavske doline številna velika sedimentna telesa, npr. fosilni plaz Podrta Gora in Gradiška Gmajna (Popit et al., 2022) in števil- ni veliki gravitacijski (podorni) karbonatni bloki. Na podlagi predhodnih raziskav Placerja in so- delavcev (2008), ter kasneje Kocjančičeve s sode- lavci (2019), je bilo samo v okolici Lokavca iden- tif iciranih 10 karbonatnih gravitacijskih blokov. Rezultati meritev so pokazali, da so dolžine pre- mikov blokov po pobočju znašale od 80 m do kar 1950 m (Kocjančič et al., 2019). Vpadi plastna- tih karbonatnih blokov so pri premiku, glede na karbonatne plasti izvornega območja, spremenili smer in naklon. Razlike pri vpadu karbonatnih plasti izvornega območja in karbonatnih blokov pa znašajo od 4° do 59°. Večji gravitacijski blo- ki, ki se pojavljajo severozahodno od Lokavca so Zasod in Školj Sv. Pavla nad Vrtovinom (Verbov- šek et al., 2019), Zasod pri plazu Selo, Kuclji nad Osekom, Vitovski hrib nad Vitovljami in številni manjši translacijsko gravitacijski bloki (sl. 6). Se- verozahodneje se pojavnost karbonatnih blokov močno zmanjša in do izvira Lijaka jih praktično ni več. Geomorfologija Trnovskega gozda, Banjšic in Šentviške planote Ob pogledu na geološko karto Trnovskega gozda ter Banjške in Šentviške planote je že na prvi pogled jasno, da tvorita Trnovska in Ban- jška planota morfotektonski blok in da je bila nekoč Šentviška planota njegov del. Prvi dve geografsko ločuje Čepovanski dol, tretjo pa v geografskem in tektonskem pomenu od Banjšic ločuje dolina Idrijce, ki si jo je izdolbla po coni Idrijskega preloma (sl. 2). 137Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain Geomorphology of the Trnovski gozd, Banjšice, and Šentviška Gora plateaus Looking at the geological map of the Trnovski gozd and the Banjšice and Šentviška Gora plateaus, it is clear at first glance that the Trnovski gozd and Banjšice plateaus form one morphotectonic block, and that the Šentviška Gora plateau was once part Vse tr i planote so zgrajene pretežno iz kar- bonatnih kamnin (sl. 4), njihovo površje je razgibano, večji uravnani površini pa nastopata na Voglarski planoti na Trnovskem gozdu (c – zgornjejurski in spodnjekredni karbonati) in na jugovzhodnem delu Banjške planote (d – zgorn- jetriasni, jurski in spodnjekredni karbonati), rock fall initiation (hillslope depresion v/u-shaped) / izvor padanja kamenja (depresijske grape v/u-oblike) MORPHOLOGY (landforms) / MORFOLOGIJA (oblika površja) head scarp line / zgornji odlomni rob (edge of escarpment (height / višina) < 2 m shear plane / strižna ploskev talus cone / melišča stožčastih oblik SEDIMENT STORAGE TYPES / VRSTA SEDIMENTACIJE Selo landslide (Long runout rock avalanche) / Plaz Selo (podorni tok velikega dosega) carbonate slope deposit / karbonatni pobočni grušč fluvial deposit / fluvialen nanos hummock on landslide / izboklina znotraj plazine 2 - 5 m > 5 m rock fall initiation (hillslope depresion) / izvor padanja kamenja (depresijsko območje) 600 2400 m12000 Mesozoic limestone and dolomites / Mezozojske karbonatne kamnine STRUCTURE / STRUKTURA Paleogene flysch / Paleogenske flišne kamnine / Sedimentary body / Sedimentna telesa Nappe and thrust sheet border / Narivna meja Tectonic fault / Prelom Normal geological boundary / Geološka meja landslide in flysch / preperinski palz v flišu translational or rotational block carbonate (breccia) slide / translacijski ali rotacijski blokovni zdrs breče flatten area of carbonate brecias as a result of rotational landslides / izravnave karbonatnih breč, kot posledica rotacijskih plazov N Vogršček accumulation lake / Akumulacijsko jezero Vogeršček Li ja k Lij ak Vipava Vipava Slano blato landslide / Plaz Slano blato Selo landslide / Plaz Selo AJDOVŠČINA NOVA GORICA Lokavec Accumulation of Vogerček lake / Akumulacijsko jezero Vogeršček Fig. 3. Geomorphological map of the forehead of Trnovo Nappe between Lijak (spring) and Lokavec (village). Sl. 3. Geomorfološka karta čela Trnovskega pokrova med Lijakom in Lokavcem. 138 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR 1 2 3 4 5 6 c e NOVA GORICA AJDOVŠČINA IDRIJA Most na Soči c d e 0 10 km So ča Soča Bača Id ri jc a G o l a k i BF P2 P2’ SOF IF ZF 7 8 9 10 11 12 IF P2 P2’ SV SV VM Fig. 3, 6 Fig. 4. Structural-litholigical sketch of the Trnovski gozd, Banjšice, and Šentviška Gora plateaus. According to the Basic Geological Map of Yugoslavia 1:100 000 – OGK (sheet Gorica: Buser, 1968; sheets Tolmin in / and Videm (Udine): Buser, 1987; sheet Kranj: Grad & Ferjančič, 1974; sheet Postojna: Buser, Grad & Pleničar, 1967), Mlakar (1969, fig. 5, fig. 8), and Placer (1973, fig. 2). Sl. 4. Strukturno-litološka skica Trnovske, Banjške in Šentviške planote. Po podatkih Osnovne geološke karte SFRJ 1:100 000 - OGK (list Gorica: Buser, 1968; lista Tolmin in Videm: Buser, 1987; list Kranj: Grad & Ferjančič, 1974; list Postojna: Buser, Grad & Pleničar, 1967), Mlakarja (1969, sl. 5, sl. 8) in Placerja (1973, sl. 2). 1 Thrust boundary of Southern Alps / narivna meja Južnih Alp 2 Boundary of the External Dinaric Thrust Belt / meja Zunanjedinarskega narivnega pasu 3 Boundary of the nappe unit within the External Dinaric Thrust Belt / meja krovne enote znotraj Zunanjedinarskega narivnega pasu 4 Fault: SOF – Sovodenj Fault, IF – Idrija Fault, ZF – Zala Fault, BF – Belsko Fault (Placer et al., 2021, fig. 6, p. 44; Buser, 1976, p. 50, Predjama Fault) / prelom: SOF – Sovodenjski prelom, IF – Idrijski prelom, ZF – Zalin prelom, BF – Belski prelom (Placer et al., 2021, sl. 6, str. 44; Buser, 1976, str. 50, Predjamski prelom) 5 Geological boundary / konkordantna geološka meja 6 Unconformity / diskordantna geološka meja 7 Predominantly carbonates / pretežno karbonati: T3 2+3, J, K1, Pc, E1 8 Predominantly clastites / pretežno klastiti: C, P1, K2, Pc, E 9 Carbonates and clastites / karbonati in klastiti: P2, T1+2, T3 1, K2 10 Karst plain: c – Voglarska planota (Voglarji plateau), d – southeastern part of Banjšice (Banjšice plateau), e – eastern part of Šentviška planota (Šentviška Gora plateau) / kraška uravnava: c – Voglarska planota, d – jugovzhodni del Banjške planote, e – vzhodni del Šentviške planote 11 Position of profile P2 – P2´ / lega profila P2 – P2´ 12 Top / vrh: VM – Veliki Modrasovec (1355 m), SV – Streliški vrh (1266 m) 139Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain manjša pa na vzhodnem delu Šentviške planote (e – zgornjetriasni karbonati). Del obravnavane- ga uravnanega sveta, ki je v geografski literaturi poimenovan tudi Banjško-trnovski ravnik, sta Stepišnik in Ferk (2023, str. 13–14) obravnavala kot korozijsko kraško uravnavo, ki je zaradi tek- tonskih procesov dvignjena nad primarni nivo. Enako je menil tudi Habič (1968). Za kompleksno razumevanje geomorfologije je poleg korozivnega vpliva potrebno upoštevati tudi strukturni in tektonski v idik geneze ozem- lja, ki sta glede na starejše interpretacije bistve- no dopolnjena. Zato si oglejmo Trnovski gozd ter Banjško in Šentviško planoto z v idika novej- ših raziskav. Kot najpomembnejše se postavlja vprašanje ali so bila neuravnana območja obrav- navanih planot nekoč uravnana. Na senčenem digitalnem modelu v išin (DMV) pridobljenem iz l idarskih podatkov je na omenjenih planotah opazit i tr i osnovne strukturno-morfološke t ipe površja (sl. 4): 1. sicer uravnano toda korozivno prizadeto površje, na katerem so opazne morfo- loško slabo odzivne razpoke v smeri SSW-NNE, 2. ostro razbrazdano površje po sistemu razpok v smeri SSW-NNE na Trnovskem gozdu, ki se razteza od meje uravnane Voglarske planote do Velikega Modrasovca (1355 m) in Streliškega vrha (1266 m) in 3. mehkejše nepravilno koro- dirano in erodirano površje na zahodnem delu Banjške in Šentviške planote, na katerem je opa- zit i različne strukturne oblike kot gube, plasti in prelome. Ožji pas uravnanega ozemlja na jugo- zahodni strani Trnovske planote od Predmeje do Vodic v tem članku ni zajet, ker bi to zahtevalo širšo strukturno razlago. Iz splošnih podatkov vemo, da so korozi- ji najbolj podvržene karbonatne kamnine, bolj apnenci kot dolomiti, manj k lastične kamnine, vendar so erozijsko manj odporne, zato je na sl. 4 prikazana strukturno-litološka skica na kateri so izr isane meje treh skupin kamnin, pretežno karbonatnih, pretežno klastičnih in mešanih. Razdelitev je groba in namenjena le predsta- vitv i v tem članku obravnavanih vprašanj. Če se omejimo samo na Trnovski gozd, Banjšice in Šentviško planoto, je uravnano površje razvito pretežno na karbonatnih kamninah zgornjetr i- asne, jurske in kredne starosti. Enako velja za močno razgibano površje. Mehkejše razgibano površje pa je razvito na območjih z mešanimi in k lastičnimi kamninami zgornjekredne in paleo- genske starosti. of it. The first two are geographically separated by the Čepovanski dol (dry valley), and the third is separated from Banjšice in a geographical and tec- tonic sense by the Idrijca River Valley, which was carved out along the Idrija fault zone (Fig. 2). All three plateaus are built mainly of carbonate rocks (Fig. 4), their surface is rugged, and larg- er level surfaces occur on the Voglarji plateau in the Trnovski gozd plateau (c – Upper Jurassic and Lower Cretaceous carbonates) and on the south- eastern part of the Banjšice plateau (d – Upper Triassic, Jurassic and Lower Cretaceous carbon- ates), and a smaller one in the eastern part of the Šentviška Gora plateau (e – Upper Triassic car- bonates). Stepišnik and Ferk (2023, p. 13–14) con- sidered the leveled part in question (which is also called the Banjšice-Trnovski gozd plain in the geo- graphical literature) a corrosive karst plain, which rises above the primary level due to tectonic pro- cesses. Habič (1968) also thought the same. For a complex understanding of the geomor- phology, in addition to the corrosive inf luence, it is also necessary to take into account the structural and tectonic aspects of the genesis of the territory, which are significantly supplemented with respect to older interpretations. Therefore, we examine Trnovski gozd, and the Banjšice and Šentviška Gora plateaus from the point of view of recent re- search. The most important question is whether the non-peneplained areas of the plateaus under consideration were once peneplained. On the shad- ed digital elevation model (DMV) obtained from lidar data, three basic structural-morphological surface types can be observed on the mentioned plateaus (Fig. 4): 1. an otherwise leveled (pene- plained) but corrosively affected surface, on which morphologically poorly responsive cracks in the SSW-NNE direction are noticeable, 2. sharply fur- rowed surface along a fracture system in the SSW- NNE direction in Trnovski gozd, which stretches from the boundary of the leveled (peneplained) Voglarji plateau to Veliki Modrasovec (1355 m) and Streliški vrh (1266 m) and 3. the softer, irreg- ularly corroded and eroded surface on the western part of the Banjšice and Šentviška Gora plateaus, on which various structural forms such as folds, layers, and fractures can be observed. The narrow strip of peneplained territory on the southwestern side of the Trnovski gozd plateau from Predmeja to Vodice is not covered in this article, as such would require a broader structural interpretation. We know from general data that carbonate rocks are more prone to corrosion, limestones more than 140 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR dolomites, and clastic rocks less so, but they are less resistant to erosion; so in Figure 4 a struc- tural-lithological sketch on which the boundaries of three groups of rocks, predominantly carbon- ate, predominantly clastic and mixed, are drawn. The division is rough and intended only to pres- ent the issues discussed in this article. If we limit ourselves to Trnovski gozd, and the Banjšice and Šentviška Gora plateaus, the f lat surface is devel- oped mainly on carbonate rocks of Upper Triassic, Jurassic, and Cretaceous age. The same applies to highly uneven surfaces. A softer rugged surface is developed in areas with mixed and clastic rocks of Upper Cretaceous and Paleogene age. How then do we approach the question of whether the entire area of the Trnovski gozd pla- teau and the Banjšice and Šentviška Gora plateaus was completely levelled before some certain time, or before the uplift of the territory? On all three S čim torej utemeljujemo vprašanje ali je bi lo celotno območje Trnovskega gozda ter Banjške in Šentviške planote pred določenim časom, ozi- roma pred dvigom ozemlja, v celoti uravnano? Na vseh treh planotah, kjer nastopajo karbonat- ne kamnine, izstopa sistem enako usmerjenih razpok v smeri SSW-NNE, ki pa je na uravnanih delih komaj ali slabo v iden, na razgibanih delih pa predstavlja glavno strukturno diskontinuite- to po kateri se je oblikovalo površje. V tem smis- lu je najbolj povedno ozemlje Voglarske plano- te in Čavna do Velikega Modrasovca (1355 m) za katerega je izdelana geomorfološka karta na sl. 3. Pri predpostavki, da je bi lo celotno obmo- čje uravnano na nižjem nivoju in pozneje dvig- njeno, postavljamo domnevo, da je bi lo dviga- nje neenotno, uravnani del Trnovskega gozda (Voglarska planota) se je dvigal enakomerno, območje jugovzhodno od tod pa neenakomerno P L A I N R U G G E D K A R S T S U R F A C E P R O F I L E P 2 - P 2 ’ A 1 2 43 0 3 km Fig. 5. Geomorphological profile P2 – P2 :́ Voglarska planota (Voglarji plateau) – Čaven (ridge) – Veliki Modrasovec (1355 m) – Lokavec (village). Position of profile in fig. 4. Sl. 5. Geomorfološki profil P2 – P2 :́ Voglarska planota – Čaven – Veliki Modrasovec – Lokavec. Lega profila na sl. 4. A – Panoramic shot of the thrust face of Trnovo Nappe. Recording location in fig. 2 / Panoramski posnetek narivnega čela Trnovskega pokro- va. Stojišče snemanja na sl. 2. B – Geomorphological profile P2 – P2´ as a kinematic model of this part of the Trnovo Nappe. Profile runs perpendicular to the regional sub-vertikal fractures in direction SSW-NNE / Geomorfološki profil P2 – P2´ kot kinematski model tega dela Trnovskega pokrova. Profil poteka pravokotno na regionalne subvertikalne razpoke v smeri SSW-NNE. 1 Carbonates / karbonati 2 Clastites (flysch) / klastiti (fliš) 3 Thrust fault surface of the Trnovo Nappes / narivna ploskev Trnovskega pokrova 4 Kinematics of regional sub-vertical fractures in direction SSW-NNE / kinematika regionalnih subvertikalnih razpok v smeri SSW-NNE 141Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain plateaus where carbonate rocks occur a system of similarly oriented fractures in the SSW-NNE di- rection stands out, which, however, is only bare- ly visible on the levelled parts, and on the rugged parts represents the main structural discontinuity along which the surface was formed. In this sense, the most telling area is the territory of Voglar- ji plateau, Mt. Čaven and Mt. Veliki Modrasovec (1355 m), for which the geomorphological map in fig. 3. is elaborated. On the assumption that the entire area was levelled at a lower level and later uplifted, we suggest that the uplift was uneven, the levelled part of Trnovski gozd (Voglarji plateau) uplifted evenly, and the area southeast of it uplifted faster and unevenly, which resulted in successive movements along the exposed fracture system and a certain degree of crushing. This was followed by in hitreje, zaradi česar je prišlo do nasledstve- nih premikov po izpostavljenem sistemu razpok in določene stopnje drobljenja. Temu je sledi- la izdatnejša korozija. Učinek tega procesa je prikazan na sl. 5, panoramskemu posnetku na sl. 5A je pri ložena grobo shematizirana kine- matska skica opisanega dogajanja v prof i lu med Voglarsko planoto in Velikim Modrasovcem na sl. 5B. Bloki (makrolitoni) med razpokami sis- tema SSW-NNE so na Voglarski planoti ostali nepremaknjeni, jugovzhodno od tod pa je med njimi prišlo do premikanja. Posledice opisanega stanja so prikazane na sl. 6, kjer so večji gravi- tacijski karbonatni bloki posejani le po pobočju pod robom planote z razgibanim reliefom, med- tem ko jih pod robom uravnane Voglarske plano- te ni. Meja med obema tipoma reliefa je zazna- planation surface / uravnano površje rugged surface / razgibano površje 600 2400 m12000 boundary between planation and rugged surface / meja med uravnanim in razgibanim površjem large carbonate blocks / večji karbonatni bloki 1 - Mala gora, 2 - Visoko, 3 - Zasod, 4 - Školj Sv. Pavla, 5 - Kuclji, 6 - Vitovski hrib Accumulation of Vegeršček lake / Akumulacijsko jezero Vogeršček Li ja k Lij ak Vipava Vipava Slano blato landslide / Plaz Slano blato Selo landslide / Plaz Selo AJDOVŠČINA NOVA GORICA Lokavec Vitovski vrh 919 m Jančerijski vrh 1155 m Veliki Modrasovec 1356 m 1 5 3 6 2 N 4 Fig. 6. Relation between geomorphology of Trnovski gozd (Trnovski gozd plateau) and gravitational phenomena. Sl. 6. Povezava med geomorfologijo Trnovskega gozda in gravitacijskimi pojavi. 142 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR more extensive corrosion. The effect of this pro- cess is shown in Figure 5. A roughly schematic ki- nematic sketch of the described event in the profile between Voglarji plateau and Veliki Modrasovec in Figure 5B is attached to the panoramic snapshot in Figure 5A. The blocks (macrolithons) between the fractures of the SSW-NNE system remained unmoved on the Voglarji plateau, but movement took place between them southeast of the area. The consequences of the described condition are shown in Figure 6, where larger gravity carbonate blocks are only scattered along the slope below the edge of the plateau with rugged relief, while they are absent below the edge of the f lat Voglarji pla- teau. The border between the two types of relief is marked by a yellow dashed line running in the SSW-NNE direction of fractures, which is why it is almost f lat and, in our opinion, indirectly proves movana z rumeno prekinjeno črto, ki poteka v smeri razpok SSW-NNE, zaradi tega je skoraj ravna in po našem mnenju posredno dokazuje, da je na tem mestu razpoklinski sistem glavni usmerjevalec geomorfološke podobe površja. Kot navidezna izjema deluje plazišče severoza- hodno od Vitovlja, vendar leži pod Vitovskim vrhom (919 m), za katerega menimo, da je nastal kot posledica selektivne korozije. Osameli gr iči so namreč pogost pojav velikih kraških uravnav. Profil P2 – P2´ na sl. 5B je v kinematskem smis- lu soroden vzdolžnemu profilu P1 – P1́ (sl. 7) na jugovzhodnem delu bližnjega Nanosa (sl. 2), kjer obstoja enak sistem regionalnih razpok v smeri SSW-NNE (Placer et al., 2021a, sl. 11, profil 1a). Enake razmere obstojajo tudi na ostalem delu Trnovskega gozda do Streliškega vrha (1266 m) (sl. 4). Nanos NW Kinematic sketch SE Suhi vrh 1313 m Strane 1 2 3 4 5 6 7 8 9km 50 0 10 00 m 1 2 3 4 5 Fig. 7. Geomorphological profile P1 – P1́ as a kinematic model of Hrušica Nappe unit at the southeastern end of Nanos plateau. The profile runs perpendicular to the regional sub-vertical fractures SSW-NNE. After Placer et al. (2021, fig. 11, profile 1a), Nanos (hamlet) – Strane (village). Position of profile in Fig. 2. Sl. 7. Geomorfološki profil P1 – P1́ kot kinematski model krovne grude Hrušiškega pokrova na jugovzhodnem koncu planote Nanos. Profil poteka pravokotno na regionalne subvertikalne razpoke SSW-NNE. Povzeto po Placer et al. (2021, sl. 11, profil 1a), Nanos (zaselek) - Strane (vas). Lega profila na sl. 2. 1 Carbonate / karbonati 2 Clastites (flysch) / klastiti (fliš) 3 Thrust surface of the Hrušica Nappe / narivna ploskev Hrušiškega pokrova 4 SSW-NNE system fracture / razpoka sistema SSW-NNE 5 Kinematics of regional subvertical fractures SSW-NNE / kinematika regionalnih subvertikalnih razpok SSW-NNE 143Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain that the fracture system is the main guide of the geomorphological surface image at this place. As an apparent exception, there is a landslide north- west of Vitovlje, but it lies below Mt. Vitovski vrh (919 m) which we believe was formed as a result of selective corrosion. Inselbergs are a frequent fea- ture of large karst formations. Profile P2 – P2´ in fig. 5B is kinematically re- lated to the longitudinal profile P1 – P1´ (Fig. 7) in the southeastern part of nearby Mt. Nanos (Fig. 2), where the same system of regional fractures in the SSW-NNE direction exists (Placer et al., 2021a, Fig. 11, profile 1a). The same conditions also exist in the rest of the Trnovski gozd plateau up to Mt. Streliški vrh (1266 m) (Fig. 4). In the area of rugged relief, the ridge of Mt. Ve- liki Golak and Mt. Mali Golak (Fig. 4) stands out, along with some peaks or groups of peaks raised above the surroundings. The Mt. Veliki and Mali Golak ridge was formed during a long period of se- lective corrosion because it lies in the area of Low- er and Middle Jurassic carbonates, which in some places are relatively less soluble than those from the Upper Jurassic. Individual peaks or groups of peaks outside the ridge are the result of the gen- eral post-thrust structural and geomorphological development of the Trnovski gozd plateau, when successive and new deformations occurred. Glaci- ation also had a part in shaping the surface (Ko- delja et al., 2013). Čepovanski dol (Dry Valley) The Čepovanski dol dry valley is a witness to the tectonic events in the wider area. The valley’s essential characteristics consist in a river that ran along it, and that it is tectonically raised together with the Trnovski gozd and Banjšice plateaus in the northeast above the Šentviška Gora plateau and in the southwest above the Vipava Valley. Above the Šentviška Gora plateau, it is raised along the Idrija Fault, and above the Vipava Valley the uplift is the result of a temporally, dynamically, and kinemati- cally complex post-thrust Neogene-recent process. In this article the process itself is not discussed, only its consequences are pointed out. As a result, the relief elevation above the Vipava Valley is not comparable to the elevation of the relief along the Idrija Fault. Let’s take a look at the Idrija fault. According to Mlakar (1964), the horizontal component of the offset along the fault is about 1950 m in Idrija. The horizontal component of the offset according to Placer (1982, p. 57) is about 2360 m, but this length also includes offsets along the Zala Fault and parallel faults between Zala and Idrija Faults Na območju razgibanega reliefa izstopa npr. greben Golakov (sl. 4), ki leži v smeri slemenitve plasti NW-SE in nekaj vrhov ali skupin vrhov dvignjenih nad okolico. Greben Golakov je nastal skozi dolgo obdobje selektivne korozije, ker leži v območju spodnje in srednjejurskih karbonatov, ki so ponekod relativno slabše topni od zgornje- jurskih. Posamezni vrhovi ali skupine vrhov iz- ven Golakov pa so posledica splošnega postna- rivnega strukturnega in geomorfološkega razvoja Trnovskega gozda, ko so nastale nasledstvene in nove deformacije. Svoj delež pri oblikovanju površja je imela tudi poledenitev (Kodelja et al., 2013). Čepovanski dol Čepovanski dol je pričevalec tektonskega dogajanja na širšem prostoru. Njegovi bistveni značilnosti sta, da je po njem tekla reka, in da je skupaj s Trnovsko in Banjško planoto tektonsko dvignjen; na severovzhodu nad Šentviško pla- noto, na jugozahodu nad Vipavsko dolino. Nad Šentviško planoto je dvignjen ob Idrijskem pre- lomu, nad Vipavsko dolino pa je dvig posledica časovno, dinamsko in kinematsko kompleksne- ga postnarivnega neogensko-recentnega proce- sa, ki ga v tem članku ne obravnavamo, temveč le opozarjamo na njegove posledice. Dvig nad Vipavsko dolino zaradi tega ni primerljiv z dvi- gom ob Idrijskem prelomu. Oglejmo si Idrijski prelom, v Idriji zna- ša horizontalna komponenta premika ob njem po Mlakarju (1964) okoli 1950 m, po Placer ju (1982, str. 57) okoli 2360 m, vendar so v to dol- žino všteti tudi premiki ob Zalinem prelomu in vzporednih prelomih med Zalinim in Idrijskim prelomom. Torej premiki ob glavni prelomni coni in ob prelomih ožjega dela idr ijske izrav- nalne zgradbe (Placer et al., 2021b, 239). Ce- lotni premik ob idrijski izravnalni zgradbi pa je nekaj večji, saj bi morali vrednosti 2360 m priš- teti še premike širšega dela izravnalne zgradbe, kot sledi iz podatkov Geološke karte idrijsko-ži- rovskega hribovja med Stopnikom in Rovtami 1:25 000 (Čar, 2010). Velikost teh pa ni znana, le sklepamo lahko na okoli 100 do 200 m. Mla- karjev podatek je vezan le na premik ob glavni prelomni coni. V Idriji je severovzhodno kri lo ugreznjeno, v išina strukturnega skoka znaša v Idriji okoli 480 m (Placer, ibid.), vendar je ta po- datek navidezen, prava v išina je bistveno manj- ša, vendar ni bi la določena. V našem primeru opisujemo razmere med Tol- minom in Dolenjo Trebušo (sl. 8A). Pri Dolenji Trebuši (sl. 9) poteka Idrijski prelom po dolini 144 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR d1 d 4 d 3 d 2 d 1 TOLMIN Dolenja Trebuša Š e n t v i š k a B a n j š i c e p l a n o t a Fig. 10 Fig. 9 VF IF LF IF Idrijca Bača paleo - Bača pa le o - I dr ijc a pa leo - Ba ča So ča paleo - Idrijc a 1 2 3 4 5 6IF A B 0 5 km d 0 145Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain Fig. 8. The influence of the Idrija Fault on the formation of the relief between Tolmin (town) and Dolenja Trebuša (village). Position of figure in fig. 2. Sl. 8. Vpliv Idrijskega preloma na oblikovanje reliefa med Tolminom in Dolenjo Trebušo. Lega slike na sl. 2. A – Current situation / Sedanje stanje. B – Situation before the formation of the Idrija Fault / Stanje pred nastankom Idrijskega preloma. 1 Fault: visible, covered or assumed: IF – Idrija Fault, VF – Volče Fault, LF – Livek Fault / prelom: viden, prekrit ali domneven: IF – Idrijski prelom, VF – Volčanski prelom, LF – Livški prelom 2 Hlevnik ridge (886 m) - Senica (576 m) / greben Hlevnik (886 m) - Senica (576 m) 3 Bučenica ridge (498 m) / greben Bučenica (498 m) 4 Selski vrh ridge (588 m) - Mrzli vrh (590 m) / greben Selski vrh (588 m) - Mrzli vrh (590 m) 5 Senica ridge (658 m) / greben Senica (658 m) 6 Horizontal component of the dextral movement of the valleys and ridges that were transversely cut by the Idrija Fault: d0 – Idrijca Valley, Dolenja Trebuša ↔ Čepovanski dol (Čepovan dry valley), d1 – Idrijca Valley, Mt. Prvejk ↔ Čepovanski dol, d2 – Bača Valley ↔ Soča Valley, d3 – Senica (658 m) ridge ↔ Selski vrh (588 m) – Mrzli vrh (590 m) ridge, d4 – Bučenica (498 m) ridge ↔ Hlevnik (886 m) – Senica (576 m) ridge; d1 ≈ d2 ≈ d3 ≈ d4 ≈ 2200 m / vodoravna komponenta desnega premika dolin in grebenov, ki jih je prečno presekal Idrijski prelom: d0 – dolina Idrijce, Dolenja Trebuša ↔ Čepovanski dol, d1 – dolina Idrijce, Prvejk ↔ Čepovanski dol, d2 – dolina Bače ↔ dolina Soče, d3 – greben Senica (658 m) ↔ greben Selski vrh (588 m) - Mrzli vrh (590 m), d4 – greben Bučenica (498 m) ↔ greben Hlevnik (886 m) - Senica (576 m); d1 ≈ d2 ≈ d3 ≈ d4 ≈ 2200 m d1 Dolenja Trebuša Č e p o v a n s k i d o l 1 2 3 d 1 Prvejk 358 m 0 2 km d 0 Fig. 9. Corrosive record of the Čepovanski dol (Čepovan dry valley) floor in the left slope of the Idrijca Valley indicating a connection with the Idrijca Valley under the northwestern slope of the Prvejk hill (358 m). Position of figure in fig. 8A. Sl. 9. Korozivni odtis dna Čepovanskega dola v levem pobočju doline Idrijce, ki kaže na povezavo z dolino Idrijce pod severozahodnim pobo- čjem Prvejka (358 m). Lega slike na sl. 8A. 1 Idrija Fault, approximate position of the main fault zone / Idrijski prelom, približna lega glavne prelomne cone 2 Čepovanski dol (Čepovan dry valley) floor / dno Čepovanskega dola 3 Horizontal componente of displacement along the Idrija Fault: d0 – the entire movement, d1 – segment movement / vodoravna kompo- nenta premika ob Idrijskem prelomu: d0 – celotni premik, d1 – segmentni premik 146 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR and represents the sum of offsets along the Idri- ja main fault zone and the offsets in the narrower zone of the Idrija adjusting structure (Placer et al., 2021b, 239). The total offset along the Idrija ad- justing structure is somewhat larger, as the offsets of the wider part of the adjusting structure, should be added to the value of 2360 m as follows from the data of the Geological map of the Idrija-Žirovs- ki vrh between Stopnik and Rovte in the 1:25,000 scale (Čar, 2010). The size of these is not known, but we can only conclude that they sum to around 100 to 200 m. Mlakar’s information is only related to movement along the main fault zone. In Idrija, the northeastern block (of the Idrija Fault) is sub- sided, the height of the structural offset in Idrija is around 480 m (Placer, ibid.), but this information is easily available; the true height is significantly lower, but was not determined. For our purposes, the situation between Dolenja Trebuša and Tolmin is described (Fig. 8A). At Do- lenja Trebuša (Fig. 9) the Idrija Fault runs along the Hotenja Valley, across the saddle on Mt. Prvejk (358 m) and further towards Tolmin along the Idri- jca Valley. The horizontal displacement along it has two measurable values, the first one is the distance between the axis of the outlet of Čepovanski dol in the left slope of the Idrijca Valley, and the axis of the Idrijca Valley northwest of Mt. Prvejk, which is denoted by d1 (around 2200 m), the second is the distance between the bottom of Čepovanski dol and the extension of the Idrijca Valley southeast of Mt. Prvejk, which is marked with d0 (around 2650 m). The distance of 2650 m is close to the total dis- placement in Idrija 2360 + 100 to 200 m = 2460 to 2560 m and represents the entire displacement in the area of Dolenja Trebuša, however, we will see that the 2200 m displacement is more important for the interpretation of the relief between Dolen- ja Trebuša and Tolmin. The discussion about the structure of the fault zone of the Idrija Fault and the formation of the valley network around Dolenja Trebuša is beyond the scope of this article, but the important fact is that the displacement d1 (2200 m) is also ref lected in the relief around Tolmin. When the axis of the Idrijca Valley on the northwestern side of Mt. Prvejk is placed opposite the bottom of the corrosive imprint of Čepovanski dol, the mouth of the Bača River is positioned opposite the middle part of the Soča Valley near the village of Most na Soči (Fig. 8B). This probably means that the Idrija Fault was originally segmented, with two segments meeting at Dolenja Trebuša, which today are com- bined into a single zone. This question cannot be solved without detailed mapping, which is why the area around Dolenja Trebuša in Fig. 8B is structur- Hotenje, čez sedlo na Prvejku (358 m) in naprej proti Tolminu po dolini Idrijce. Horizontalni premik ob njem ima dve izmerljiv i vrednosti, prva je razdalja med osjo izteka Čepovanskega dola v levem pobočju doline Idrijce in osjo do- line Idrijce severozahodno od Prvejk, kar je označeno z d1 (okoli 2200 m), druga je razdal- ja med dnom Čepovanskega dola in podaljškom doline Idrijce jugovzhodno od Prvejka, kar je označeno z d0 (okoli 2650 m). Razdalja 2650 m je blizu skupnemu premiku v Idriji 2360 + 100 do 200 m = 2460 do 2560 m in predstavlja ce- lotni premik na območju Dolenje Trebuše, k ljub temu pa bomo videli, da je za razlago reliefa med Dolenjo Trebušo in Tolminom pomembnejši premik 2200 m. Razprava o zgradbi prelomne cone Idrijskega preloma in o nastanku dolinske mreže okoli Dolenje Trebuše presega okvir tega č lanka , pomembno pa je dejstvo, da se premik d1 (2200 m) odraža tudi v reliefu okoli Tolmina, ko namreč postavimo os doline Idrijce na severoza- hodni strani Prvejka nasproti dna korozivnega odtisa Čepovanskega dola, se ustje Bače postavi nasproti sredine doline Soče pri Mostu na Soči (sl. 8B). To ver jetno pomeni, da je bi l Idrijski prelom prvotno segmentiran pri čemer sta se v Dolenji Trebuši srečala dva segmenta, ki sta danes združena v enotno cono. Tega vprašanja ni mogoče rešit i brez detajlnega kartiranja, zato je prostor okoli Dolenje Trebuše na sl. 8B struk- turno neobdelan. Ko stoji dolina Bače nasproti doline Soče (sl. 8B) se; greben Selski vrh (588 m) - Mrzli vrh (590 m) se postavi nasproti grebena Seni- ce (658 m) nad Modrejem (sl. 8A, d3), greben Bučenice (498 m) nad Modrejcami se posta- vi v vzhodno-jugovzhodni podaljšek grebena Hlevnik (886 m) - Senica (576 m) nad Volčami (sl. 8A, d4). Iz slike 8B je torej mogoče povzeti, da je paleo-Idrijca tekla po Čepovanskem dolu in da je paleo-Bača tekla po sedanji dolini Soče južno od Mosta na Soči. Na podlagi gornjih ugo- tovitev smatramo razdaljo okoli 2200 m za refe- renčni premik ob Idrijskem prelomu na območju Tolmina in Dolenje Trebuše. To lahko izrazimo z zapisom d1 ≈ d2 ≈ d3 ≈ d4 ≈ 2200 m. Do kvalitativno enake ugotovitve o vplivu Idrijske- ga preloma na odnos doline Idrijce do Čepovan- skega dola in doline Bače do doline Soče južno od Mosta na Soči, so prišli Miklavž Feigel (ustna izjava, 1973) in Moulin et al. (2016, sl. 5). Podatka o premiku d1 in d2 sta v isoko pri- čevalna, medtem ko ima d3 ob d2 le vzporeden pomen. Podatek d4 je lahko realen ali sluča- jen, saj glede na nadaljnje izvajanje ne moremo 147Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain ally not resolved. The course of the Fault in the Tol- min area is described in more detail, which is why a topographical sketch is attached for easier orienta- tion (Fig. 10). The terms “total displacement” for d0 and the “segmental displacement” for d1 in Figure 9 are only relevant for explaining the situation in the Dolenja Trebuša area. When Bača Valley is positioned opposite the Soča Valley Mt. Selski vrh ridge (588 m) – Mt. Mr- zli vrh (590 m) is located opposite the Mt. Senica ridge (658 m) above Modrej village (Fig. 8A, d3), the Mt. Bučenica ridge (498 m) above Modrej is lo- cated in the east-southeastern extension of the Mt. Hlevnik ridge (886 m) – Mt. Senica (576 m) above Volče (Fig. 8A, d4). It can therefore be concluded from Figure 8B that the paleo-Idrijca f lowed along the Čepovanski dol and that the paleo-Bača f lowed along the present Soča Valley south of the village of trdit i, da je greben Hlevnik - Senica - Bučenica obstajal že pred nastankom Idrijskega preloma. Trasa preloma na sl. 8 sloni na interpretaciji kot jo je podal Buser (1986; 1987) na Osnovni geološki karti, l ista Tolmin in Videm; od sedla med Bučenico in Kukom nad Kozarščem poteka proti severozahodu, oziroma proti Kobaridu, ne pa proti zahodu-severozahodu proti Volčam, kot menijo Moulin et al. (2016, sl. 5). Za tako odlo- čitev obstoja več razlogov: 1. razvoj pliocenske- ga porečja Soče po Meliku (1956), 2. geološki podatki na Osnovni geološki karti 1:100.000, l ista Tolmin in Videm (Buser ibid.), 3. ugrez severovzhodnega kri la Idrijskega preloma in 4. kr iter ij desnozmičnega premika 2200 m na ob- močju Tolmina in Dolenje Trebuše, kot je prika- zan v tem članku. 0 2 km VF LF IF IF Fig. 10. Topographic map of the wider area around the Soča confluence, Tolminka, and Idrijca rivers. According to Geopedia – interactive online atlas and map of Slovenia. Explanation in Fig. 8. Sl. 10. Topografska karta širše okolice sotočja Soče, Tolminke in Idrijce. Povzeto po Geopedia - interaktivni spletni atlas in zemljevid Slove- nije. Legenda na sl. 8. 148 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR Most na Soči. Based on these findings, we consider a distance of around 2,200 m as a reference offset along the Idrija fault in the area of Tolmin and Do- lenja Trebuša. This can be expressed as d1 ≈ d2 ≈ d3 ≈ d4 ≈ 2200 m. Miklavž Feigel (oral statement, 1973) and Moulin et al. (2016, Fig. 5) came to the same qualitative conclusion about the impact of the Idrija Fault on the relationship between the Idrijca Valley, the Čepovanski dol, the Bača Valley, and the Soča Valley south of Most na Soči (2016, Fig. 5). The data on the d1 and d2 offsets are highly tes- timonial, while d3 has only a parallel meaning with d2. The d4 data may be representative or coinciden- tal, since according to further implementation we cannot claim that the Hlevnik - Senica - Bučenica ridge already existed before the formation of the Idrija Fault. The Idrija Fault trace in Figure 8 is based on the interpretation given by Buser (1986; 1987) on the Basic Geological Map, sheet Tolmin and Videm; from the saddle between Mt. Bučenica and Mt. Kuk above the village of Kozaršče, it runs towards the northwest, or rather towards Kobar- id, but not WNW towards Volče, as Moulin et al. (2016, Fig. 5) suggested. There are several reasons for such a decision: 1. the development of the Plio- cene Soča basin according to Melik (1956), 2. geo- logical data on the basic geological map 1:100,000, the Tolmin and Videm sheets (Buser, ibid), 3. the subsidence of the northeastern block of the Idrija Fault, and 4. the criterion of a 2,200 m dextral off- set in the area of Tolmin and Dolenja Trebuša, as shown in this article. Ad 1. Melik (1956, Fig. II) in his discussion about the Middle Pliocene assumes that the pa- leo-Soča f lowed through the valley between Ko- barid and Robič, and then through the present-day Nadiža gorge towards the south. Melik (ibid) also assumed that the paleo-Idrijca river f lowed through the Čepovanski dol valley, and that today’s hanging Livek Valley SE of the village of Livek (Fig. 2) had a wide watershed in its hinterland, which was fed from the area northeast of Livek and today appears completely denuded. The description applies to the situation before the formation of the Idrija Fault. It is also indirectly proven by the f low of the Soča River, which f lows north of Kobarid across the fron- tal part of the Southern Alps thrust independently of the bundle of faults that were created later and which we believe are related to the Idrija Fault. The assumption is supported by the 1:100,000 scale Ba- sic geologic map, Tolmin and Videm sheet (Buser, 1986; 1987). The Livek hanging valley is the main geomor- phological object that indicates the f low of the pa- leo-Soča River towards the present-day Nadiža Ad 1. Melik (1956, sl. II) v svoji razpravi za obdobje srednjega pliocena domneva, da je pa- leo-Soča tekla po dolini med Kobaridom in Ro- bičem, nato pa po današnji soteski Nadiže proti jugu, da je paleo-Idrijca tekla po Čepovanskem dolu in da je imela danes v iseča Livška doli- na (sl. 2) tedaj široko zaledje. Napajala se je z območja severovzhodno od Livka, ki je danes povsem denudirano. Opis velja za stanje pred nastankom Idrijskega preloma, kar posredno dokazuje tudi tok Soče, ki severno od Kobarida teče preko čelnega dela nariva Južnih Alp ne- odvisno od pozneje nastalega snopa prelomov, za katere menimo, da so povezani z Idrijskim prelomom. Podlaga za to domnevo so podatki Osnovne geološke karte, l ista Tolmin in Videm (Buser, 1986; 1987). Viseča Livška dolina je glavni geomorfološki objekt, ki kaže na tok paleo-Soče proti današ- nji dolini Nadiže. Na območju Livka ima med Kolovratom in Matajur jem značilnosti pradoli- ne, katere pobočja dosežejo do 500 m višine, pri Čepovanskem dolu pa največ okoli 400 m. Na podlagi tega je moč sklepati, da je imelo denu- dirano porečje zgornjega dela l ivške paleoreke znaten obseg. V času nastanka Melikove razprave so Idrij- ski prelom obravnvali kot disjunktivno deforma- cijo, ki naj bi imela ponekod učinek reverznega, ponekod normalnega preloma. Rakovec (1956, str. 79) ga je potegnil do Kobarida in Učje. Des- nozmično komponento Idrijskega preloma je utemelji l Mlakar (1964). Ad 2. Po podatkih Osnovne geološke karte (OGK), l ista Tolmin in Videm (Buser, ibid.), je trasa Idrijskega preloma od sedla med Bučenico in Kukom nad Kozarščem (sl. 10), usmerjena pro- t i severozahodu. Naprej poteka pod severovzho- dnim pobočjem grebena Hlevnik - Senica in po Soški dolini do Kobarida ter po severovzhodnem pobočju grebena Mali vrh (1405 m) - Starijski vrh (1146 m) proti spodnjemu delu doline Učje nad Žago (Čar & Pišljar, 1993; Gosar, 2022). Pri Libušnjah se na severovzhodno stran cone Idrij- skega preloma naslanja narivna meja Južnih Alp, ki se pri Kobaridu od nje odcepi. Zahodno od tod se nadaljuje pod imenom prelom Barcis - Staro selo. Premik narivne meje Južnih Alp ob Idrijskem prelomu je desnozmičen, navidezna dolžina premika znaša okoli 3,5 km, vendar gre za učinek, ki je posledica ugreza severovzhodne- ga kri la Idrijskega preloma in položnega vpada narivne meje Južnih Alp. Dejanski desnozmič- ni premik je manjši, vendar njegove velikosti ni mogoče ugotovit i. 149Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain Valley. In the area of the village of Livek, between Mt. Kolovrat and Mt. Matajur, it has the charac- teristics of a deep valley, with slopes that reach a height of up to 500 m, while the maximum valley depth at Čepovanski dol is around 400 m. With this in mind, we can conclude that the denuded basin of the upper part of the Livek paleo-river had a signif- icant extent. At the time of Melik’s treatise, the Idrija Fault was treated as a brittle deformation, which was supposed to have the effect of a reverse fault in some places, and a normal fault in others. Rakovec (1956, p. 79) drew it to Kobarid and Učja. The dex- tral offset component of the Idrija Fault was estab- lished by Mlakar (1964). Ad 2. According to the Basic Geological Map 1:100,000 (OGK), sheet Tolmin and Videm (Bus- er, ibid.), the Idrija Fault trace from the saddle be- tween Mt. Bučenica and Mt. Kuk above Kozaršče village (Fig. 10) is directed towards the northwest. It continues under the northeastern slope of the Mt. Hlevnik – Mt. Senica ridge and along the Soča Valley to Kobarid and along the northeastern slope of the Mt. Mali vrh (1405 m) – Mt. Starijski vrh (1146 m) ridge towards the lower part of the Učja Valley above the village of Žaga (Čar & Pišljar, 1993; Gosar, 2022). Near Libušnje, the thrust boundary of the Southern Alps leans on the northeastern side of the Idrija Fault zone, which splits off near Ko- barid. To the west it continues as the Barcis - Staro selo Fault. The offset of the thrust boundary of the Southern Alps along the Idrija Fault is dextral, with an apparent offset of about 3.5 km. The actual dex- tral displacement is smaller due to the subsidence of the northeastern block of the Idrija Fault and the gentle dip of the Southern Alps boundary thrust. The true offset, however, cannot be ascertained. On the saddle between Mt. Bučenica and Mt. Kuk, before Volče, the stratigraphically and geo- morphologically responsive Volče Fault (Fig. 8) splits off from the Idrija Fault, which runs along the southwestern slope of the Mt. Hlevnik – Mt. Senica ridge. Due NW it continues across the saddle be- tween Mt. Hlevnik (886 m) and the Mt. Kolovrat ridge into the Soča Valley. Between Mt. Kuk and Mt. Mengore ( just south of it), another fault branch- es off from the Idrija Fault (Jamšek Rupnik et al., 2022), whose route, in our opinion, passes the vil- lage of Livek and continues due NW towards Robič. The fault between Robič and Livek was mapped by Buser, who marked it due southeast to the upper Idrijca River and named it the Livek Fault. How- ever, the structural and remote detection data indi- cate a connection from Livek to the aforementioned saddle above Kozaršče, so we suggest that the lat- Na sedlu med Bučenico in Kukom se pred Vol- čami od Idrijskega preloma odcepi stratigrafsko in geomorfološko jasno odziven Volčanski pre- lom (sl. 8), ki poteka po jugozahodnem pobočju grebena Hlevnik - Senica. Nato se prevesi pre- ko sedla med Hlevnikom (886 m) in grebenom Kolovrata v Soško dolino. Med Kukom in Men- gorami nad Kozarščem se od Idrijskega prelo- ma odcepi drugi prelom (Jamšek Rupnik et al., 2022), katerega trasa po našem mnenju poteka mimo Livka in naprej proti Robiču. Prelom med Robičem in Livkom je kartiral Buser, potegnil ga je proti jugovzhodu na zgornjo Idrijco in ga poimenoval Livški prelom. Toda strukturni po- datki in zaznambe daljinske detekcije, kažejo na povezavo od Livka proti omenjenemu sedlu nad Kozarščem, zato predlagamo, da se slednja va- r ianta obravnava kot Livški prelom (sl. 8). Naše mnenje temelji na primerjavi podatkov Geološke karte Benečije Julijske krajine (Carulli, 2006) in Osnovne geološke karte Jugoslavije merila 1: 100.000, l istov Tolmin in Videm (Buser, 1986; 1987). Ta je pokazala, da se zahodno od Idrij- skega preloma uveljavlja drugačna dinamika neogensko-recentnih deformacij. To se odraža v njihovi smeri in kinematiki, vendar razprava o tem presega okvir tega č lanka. Ad 3. Sklepamo, da je Idrijski prelom odre- zal zgornje povir je l ivške paleoreke od njenega osrednjega in spodnjega toka. Rez je bi l učinko- v it zato, ker se je severovzhodno kri lo preloma ugreznilo, oziroma jugovzhodno kri lo dvignilo in s tem preprečilo odtok voda zgornjega povod- ja l ivške paleoreke proti jugozahodu. Te so se potem lahko odvajale le proti severozahodu ali jugovzhodu. Pričel se je proces nastajanja doline med Kobaridom in Tolminom, ki je bi l učinko- vit tudi zaradi bližine narivne meje Južnih Alp. Najprej sta nastali porečji dveh potokov od ka- ter ih je eden napajal paleo-Sočo, drugi paleo- -Bačo. Sčasoma je nastala dolina, v katero se je iz doslej še neraziskanih razlogov preusmerila Soča. Dolina med Kobaridom in Tolminom bi lah- ko nastala tudi zaradi same narivne meje Juž- nih Alp brez Idrijskega preloma, vendar kažeta Volčanski prelom in desni premik narivne meje Južnih Alp med Kobaridom in Libušnjami na traso, kot so jo razumevali Rakovec (1956), Ar- sovski & Feigel (1973) in Buser (1986, 1987). 150 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR ter variant be considered the Livek Fault (Fig. 8). Our opinion is based on a comparison of the data of the Geological Map of the Veneto Julian Region (Carulli, 2006) and the Basic Geological Map of Yu- goslavia, 1:100,000 scale, Tolmin and Videm sheet (Buser, 1986; 1987). This showed that a different dynamic of Neogene-recent deformations is taking place west of the Idrija Fault, which is ref lected in their direction and kinematics, but discussion of this is beyond the scope of this article. Ad 3. We conclude that the Idrija Fault cut off the upper headwaters of the Livek paleo-river from its central and lower course. The cut was effective because the northeastern f lank of the fault subsid- ed, or the southeastern f lank rose, thereby prevent- ing drainage of the waters of the upper catchment of the Livek paleo-river towards the southwest. These waters could then be discharged only towards the northwest or southeast. Thus, the process of for- mation of the valley between Kobarid and Tolmin began, which was also effective due to the proxim- ity of the Southern Alps Thrust Boundary. First, the basins of two watersheds were formed, one of which fed the paleo-Soča, the other the paleo-Bača River. Over time, a valley was formed into which the Soča River diverted for as yet unexplained and unexplored reasons. The valley between Kobarid and Tolmin may also have been formed by the Southern Alps Thrust Boundary without the Idrija Fault, but the Volče Fault and the right lateral shift of the Southern Alps Thrust Boundary between Kobarid and the village of Libušnje show the trace as understood by Rakovec (1956), Arsovski & Feigel (1973), and Buser (1986; 187). Ad 4. The displacement criterion of 2200 m can be used for displacements d2, d3, and d4 in the Tolmin area (Fig. 8A), while the of valley network between Tolmin and Sela pri Volčah indicates a multiphase development. This only reinforces the assumption that before the formation of the Idri- ja Fault, the paleo-Soča did not f low here and that the area between Tolmin and Sela pri Volčah was formed by several streams that fed the paleo-Bača River from the northwestern side. In Figure 8B, no variant on the geomorphological development of this area is given, but we would like to draw atten- tion to the Mt. Selski vrh – Mt. Mrzli vrh – Mt. Sen- ica (658 m) ridge, which was probably continuous, before the formation of the Idrija Fault, so the water of all the streams f lowed into the paleo-Bača River in the area of Sela pri Volčah exclusively. The above four considerations lend a relative- ly high probability to the interpretation of the pa- leo-Soča f low from Kobarid to the west and to the Ad 4. Kriter ij zmika 2200 m je na območju Tolmina mogoče uporabit i pr i premiku d2, d3 in d4 (sl. 8A), medtem ko splet dolin med Tol- minom in Selami pri Volčah kaže na večfaz- ni razvoj. To le utr juje domnevo, da pred nas- tankom Idrijskega preloma paleo-Soča tu še ni tekla in da je prostor med Tolminom in Selami pri Volčah oblikovalo več potokov, ki so napaja- l i paleo-Bačo s severozahodne strani. Na sl. 8B ni podane nobene variante o geomorfološkem razvoju tega prostora, opozorili bi pa na greben Selski vrh - Mrzli vrh -Senica (658 m), ki je bi l pred nastankom Idrijskega preloma ver jetno sklenjen, zato je voda vseh potokov odtekala v paleo-Bačo le na območju Sel pri Volčah. Navedeni št ir je premisleki dajejo sorazmer- no v isoko stopnjo ver jetnosti interpretaciji toka paleo-Soče od Kobarida proti zahodu in inter- pretaciji trase Idrijskega preloma od sedla med Bučenico in Kukom proti severozahodu. Ven- dar je potrebno obe tezi k ljub temu preverit i. Katera reka je urezala dolino med Robičem in Kobaridom bi se dalo ugotovit i s sondiranjem, s katerim bi določili smer imbrikacije plošča- t ih prodnikov; če je ta nagnjena proti zahodu je dolino izdolbla Soča, v nasprotnem primeru Nadiža. Sondiranje bi moralo odgovorit i tudi na vprašanje morebitne ojezeritve in njene starosti. Traso Idrijskega preloma je mogoče preverit i z razkopi ali geof izikalnim prof i l iranjem v dolini Soče, najprimernejše mesto preverbe je prostor pod severovzhodnim pobočjem grebena Hle- vnik - Senica. Raziskave v Modrejcah (Jamšek Rupnik- et al., 2022) so bile izvedene korektno, niso pa mogle dati odgovora na to vprašanje. Prispevek o genezi rečnega reliefa na območju zgornje Nadiže (Diercks et al., 2021) ne posega v to razpravo, čeprav je v njem uporabljena inter- pretacija Moulin et al. (2016, sl. 5), da je Nadiža urezala dolino med Robičem in Kobaridom. Pred nastankom Idrijskega preloma sta Banj- ška in Šentviška planota tvorili enovito »Banj- ško-Šentviško planoto« (sl. 8B). Če bi hoteli bolj dosledno rekonstruirati takratno stanje, bi mora- li Šentviško planoto dvigniti za okoli 150 m, ali obratno, in odmisliti dolino Idrijce med njima. V tem članku ne opisujemo strukturnih razmer na jugozahodni strani Banjške in Trnovske planote nad Vipavsko dolino, ugotavljamo pa, da so litolo- ška sestava (eocenski f liš ter kredni, paleocenski in eocenski karbonati), razporeditev (f liš v talni- ni, karbonati v krovnini, meja med njimi subhori- zontalna krovna narivna ploskev) in kinematika, primerljivi z istrsko-furlansko narivno-podrivno cono (Placer et al., 2023, sl. 1, str. 13). V profilu 151Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain interpretation of the route of the Idrija Fault from the saddle between Mt. Bučenica and Mt. Kuk to the northwest. However, it is still necessary to ver- ify both theses. Which river cut the valley between Robič and Kobarid could be determined by probing, which would determine the direction of imbrication of f lat pebbles; if it is inclined to the west, the valley was carved out by the Soča River, and if inclined otherwise by the Nadiža. Sounding should also an- swer the question of possible lake formation there and the age of such. The Idrija Fault trace can be verified by trenching or geophysical profiling in the Soča Valley; the most suitable place for verification is the area under the northeastern slope of the Mt. Hlevnik – Mt. Senica ridge. Research at the village of Modrejce (Jamšek Rupnik et al., 2022) was car- ried out correctly but did not provide a conclusive answer to the question. The paper on the genesis of the river relief in the area of the upper Nadiža River (Diercks et al., 2021) does not play a role in this discussion, though it does use the interpretation of Moulin et al. (2016, Fig. 5) that the Nadiža cut the valley be- tween Robič and Kobarid. Before the formation of the Idrija Fault, the Banjšice and Šentviška Gora plateaus formed a single plateau (Fig. 8B). If we wanted to recon- struct a more consistent picture of the situation at the time, we would have to raise the Šentviška, Gora plateau by about 150 m, or vice versa, and discard the Idrijca Valley between them. In this article we do not describe the structural conditions on the southwestern side of the Banjšice and Trnovski gozd plateaus above the Vipava Valley, but we note that the lithological composition (Eo- cene f lysch and Cretaceous, Paleocene, and Eocene carbonates), distribution (f lysch in the footwall, carbonates in the hanging wall and subhorizontal thrust plane between them) and kinematics are comparable to the Istra-Friuli Thrust-Underthrust Zone (Placer et al., 2023, Fig. 1, p. 13). In the profile of the Istra-Friuli Thrust-Underthrust Zone (ibid., fig. 8), two types of deformations stand out: under- thrust reverse faults and antiformally bent Paleo- gene thrust surfaces located next to them; both are related to the uplift of the hanging wall of the un- derthrust reverse faults. The equivalent of the anti- formally bent nappe thrust plane on the boundary between the Vipava Valley (External Dinaric Im- bricated Belt) and the Trnovski gozd plateau with Mt. Hrušica (External Dinaric Thrust Belt) is the Nanos-Čaven antiform (Placer et al., 2021a, p. 56- 58; 2023, p. 38), the equivalent of the underthrust reverse faults are represented by structures whose description requires extensive substantiation, so istrsko-furlanske narivno-podrivne cone (ibid., sl. 8) izstopata dva tipa deformacij, podrivni re- verzni prelomi in ob njih antiformno usločene pa- leogenske narivne ploskve; oboje je povezano z dvigom krovninskega krila podrivnih reverznih prelomov. Ekvivalent antiformno usločene krovne narivne ploskve na meji med Vipavsko dolino (Zu- nanjedinarski naluskani pas) in Trnovskim goz- dom s Hrušico (Zunanjedinarski narivni pas), je nanoško-čavenska antiforma (Placer et al., 2021a, str. 56–58; 2023, str. 38), ekvivalent podrivnih reverznih prelomov pa predstvavljajo strukture, katerih opis zahteva obširno utemeljevanje, zato bodo predstavljene v posebnem prispevku. Za dokaz dviga uravnanega območja Trnovskega gozda in Banjške planote zadostu- je že sam obstoj Čepovanskega dola, saj dol kot nekdanja rečna dolina ni mogel delovati na se- danji nadmorski v išini, urezovanje v primarno uravnavo na začetku njegovega nastajanja pa se je moralo dogajati na še nižjem nivoju. Sklep Nad severovzhodnim obrobjem Vipavske do- line, ki je zgrajena iz f lišnih kamnin Zunanjedi- narskega naluskanega pasu, se dvigajo karbonat- ne kamnine Zunanjedinarskega narivnega pasu (planote Banjšice, Trnovski gozd, Nanos), ki so bile tja narinjene v paleogenu v zaključnem ob- dobju narivne faze nastajanja Dinaridov. Nari- njene karbonatne kamnine se danes gravitacijsko sprožajo v Vipavsko dolino, ta proces traja že sub- recentno in recentno obdobje, zato sklepamo, da se omenjene planote postopoma dvigajo. Dviganje ob severovzhodnem obrobju Vipa- vske doline se ne dogaja ob paleogenskih krovnih narivnih ploskvah, ki so tu subhorizontalne in blago tonejo proti severozahodu, temveč ob pod- rivnih reverznih prelomih smeri NW-SE, ki pa so šele v fazi proučevanja. Ti so posledica pomi- kanja Jadranske mikroplošče (Mikroadrija) proti Dinaridom. Desnozmični prelomi v smeri NW-SE imajo v tem primeru podrejeno vlogo. Premikanje Mikroadrije proti Dinaridom pote- ka domnevno vse od srednjega miocena, zato ga obravnavamo kot neogensko-recentno dogajanje. Poleg splošnih geomorfoloških pojavov na širšem prostoru severozahodnih Dinaridov (istrsko po- tisno območje) to dokazujejo tudi pojavi na Banj- šicah in Trnovskem gozdu: 1. Kraških uravnav na Trnovskem gozdu (Voglarska planota) in Banjši- cah ( jugovzhodni del) ne moremo razlagati s kra- jevno omejenimi procesi. 2. Korozivna degradacija teh uravnav je povezana s poostritvijo klimat- skih razmer zaradi dviganja Zunanjedinarskega 152 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR they are to be presented in a special, separate paper. The very existence of the Čepovanski dol is enough to prove the elevation of the peneplained area of the Trnovski gozd and the Banjšice plateaus, since the Čepovanski dol, as a former river valley, could not function at its current altitude, and the cutting into primary regulation at the beginning of its formation had to take place at a level even lower that of today. Conclusions The carbonate rocks (Banjšice and Trnovs- ki gozd plateaus, Nanos) that were overthrusted there in the Paleogene during the final period of the thrust phase of the formation of the Dinarides rise above the northeastern edge of the Vipava Valley, which is built from the f lysch rocks of the External Dinaric Imbricated Belt. The eroded car- bonate rocks are now gravitationally launched into the Vipava Valley, which process has been going on over the course of the sub-recent and recent pe- riods, so we conclude that the mentioned plateaus are gradually rising. The uplift along the northern margin of the Vipava Valley does not take place along the sub- horizontal Paleogene nappe thrust planes, dipping slightly to the northwest, but rather along the NW- SE trending underthrust reverse faults which are still in the study phase. These are a consequence of the Microadria movement towards the Dinarides where the right lateral NW-SE trending strike-slip faults play a subordinate role. The movement of the Microadria towards the Dinarides has presumably been going on since the Middle Miocene, so we treat it as a Neogene-re- cent event. In addition to the general geomorphic phenomena in the wider area of the northwest- ern Dinarides (Istran Pushed Zone), this is also proven by phenomena in the Banjšice and Trnovs- ki gozd plateaus: 1. The karstic peneplanation in the Trnovski gozd plateau (Voglarji plateau) and the Banjšice plateau (southeastern part) cannot be explained by locally limited processes. 2. The cor- rosive degradation of these peneplains (plateaus) is related to the aggravation of climatic conditions due to the uplift of the External Dinaric Thrust Belt. 3. Čepovanski dol was active (hosted a river) at a lower altitude, and at the beginning of cutting into the levelled karst surface it must have lay even lower. We note that in addition to the existing karstic peneplanations in the Banjšice and Trnovski gozd plateaus, the rest of the Trnovski gozd area was also peneplained from the Voglarji plateau in the southeast to Mt. Veliki and Mt. Mali Modrasovec narivnega pasu. 3. Čepovanski dol je bil pretočno aktiven na nižjem nadmorskem nivoju, na začet- ku urezovanja v uravnano kraško površje pa je moral ležati še nižje. Ugotavljamo, da je bil poleg obstoječih kra- ških uravnav na Banjšicah in Trnovskem gozdu, uravnan tudi preostali del Trnovskega gozda od Voglarske planote proti jugovzhodu do Velikega in Malega Modrasovca nad Lokavcem in Streliškega vrha nad Podkrajem pri Colu. Enako domnevamo tudi za danes neuravnani del Banjšic in Šentviške planote. Zato uvajamo termin trnovsko-banjško- -šentviška degradirana uravnava. Obseg trnovsko-banjško-šentviške degradira- ne uravnave je prikazan na sliki 11. Pri nižji nad- morski višini je bilo celotno območje uravnano, med dviganjem pa je strukturno in denudacijsko degradiralo. Degradacija ni bila enotna temveč podrejena litološki sestavi, strukturi in dinamiki dviganja. Danes so na tem prostoru razviti trije različni tipi reliefa, ki so nastali po načinu degra- dacije prvotne uravnave. Na relativno umirjenem delu iz karbonatnih kamnin, kjer strukturna de- gradacija ni imela vpliva, so vidne le posledice ostrejših klimatskih pogojev, ta del je označen kot korozivno degradirana kraška uravnava (I); del iz karbonatnih kamnin, ki je danes razgiban, je označen kot strukturno in korozivno degradirana kraška uravnava (II); del iz mešanih kamnin, ki je danes umirjeno razgiban je označen kot struk- turno degradirana in denudirana uravnava (III), tu je delež korozivne degradacije podrejen zaradi prisotnosti klastičnih kamnin. Vplivno območje korozivno degradiranih kraških uravnav (I) je identično z vplivnimi območji c, d in e (I ≡ c, d, e) (sl. 2, 4). Trnovsko-banjško-šentviška degradirana ura- vnava leži na najvišjem območju Trnovskega po- krova, ki je zgrajeno iz karbonatnih kamnin. Ta del je proti jugovzhodu ohranjen le do Streliškega vrha (1266 m), od tu naprej pa je erodiran; na mestu je torej domneva, da je bila obravnavana uravnava ob svojem nastanku večja od površine kot je predstavljena na sl. 11, zato bi sodila po definiciji Stepišnika in Ferkove (2023, 12–13) v razred korozijskih uravnav. Temu pritrjuje tudi sodobni pogled na njihovo genezo (ibid. 17–18). V tem članku ni obdelan geološki pomen Poni- kvanske tektonske krpe na Šentviški planoti. Ob- delan ni tudi pomemben podatek, da je Šebreljska planota vzhodni podaljšek Šentviške planote na drugi strani doline Idrijce. Vsa našteta dejstva in domneve terjajo teme- ljit premislek o ponarivni, oziroma popaleogenski genezi Dinaridov. 153Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain 1 2 3 4 5 6 NOVA GORICA AJDOVŠČINA IDRIJA Most na Soči Šebrelje 0 10 km So ča Soča Bača Id ri jc a G o l a k i SOF IF ZF 7 8 9 10 11 IF SV SV III III III II II III I I I III BF VM Fig. 11. Trnovski gozd-Banjšice-Šentviška planota degraded plain. Sl. 11. Trnovsko-banjško-šentviška degradirana uravnava. 1 Thrust boundary of Southern Alps / narivna meja Južnih Alp 2 Boundary of the External Dinaric Thrust Belt / meja Zunanjedinarskega narivnega pasu 3 Boundary of the nappe unit within the External Dinaric Thrust Belt / meja krovne enote znotraj Zunanjedinarskega narivnega pasu 4 Fault: SOF – Sovodenj Fault, IF – Idrija Fault, ZF – Zala Fault, BF – Belsko Fault (Placer et al., 2021, fig. 6, p. 44; Buser, 1976, p. 50, Predjama Fault) / prelom: SOF – Sovodenjski prelom, IF – Idrijski prelom, ZF – Zalin prelom, BF – Belski prelom (Placer et al., 2021, sl. 6, str. 44; Buser, 1976, str. 50, Predjamski prelom) 5 Concordant geological border / konkordantna geološka meja 6 Discordant geological border / diskordantna geološka meja 7 Predominantly carbonates / pretežno karbonati: T3 2+3, J, K1, Pc, E1 8 Predominantly clastites / pretežno klastiti: C, P1, K2, Pc, E 9 Carbonates and clastites / karbonati in klastiti: P2, T1+2, T3 1, K2 10 Area of the Trnovski gozd-Banjšice-Šentviška planota degraded plain / območje trnovsko-banjško-šentviške degradirane uravnave. Type of dominant degradation: I – corrosive degradation (I ≡ c, d, e: see fig. 2, fig. 4), II – structural and corrosive degradation, III – structural degradation and denudation / tip prevladujoče degradacije: I – korozivna degradacija (I ≡ c, d, e: glej sl. 2, sl. 4), II – strukturna in korozivna degradacija, III – strukturna degradacija in denudacija 11 Top / vrh: VM – Veliki Modrasovec (1355 m), SV – Streliški vrh (1266 m) 154 Ladislav PLACER, Tomislav POPIT & Igor RIŽNAR above Lokavec and Mt. Streliški vrh above Pod- kraj pri Colu. We assume the same for the cur- rently non-peneplained part of Banjšice and the Šentviška Gora plateaus – which is why we here introduce the term Trnovski gozd-Banjšice-Šent- viška Gora degraded peneplain. The extent of the Trnovski gozd-Banjšice-Šent- viška Gora plateaus degraded peneplanation is shown in Figure 11. At a lower altitude the entire area was levelled, but during the uplift it degraded structurally and denudationally. The degradation was not uniform but subordinated to the litholog- ical composition, structure, and uplift dynamics. Today, three different types of relief have been de- veloped in this area, formed according to the type of degradation of the original peneplain. On the relatively unactive part built of carbonate rocks, where structural degradation had no effect, only the consequences of harsher climatic conditions are visible; this part is designated as corrosively degraded karst plain (I); the part built of carbon- ate rocks, which is uneven today, is designated as a structurally and corrosively degraded karst plain (II); the part made of various (carbonate and clas- tic) rocks, which today is moderately rugged, is designated as structurally degraded and denuded plain (III); here the proportion of corrosive degra- dation is subordinate due to the presence of clastic rocks. The inf luence zone of corrosively degraded karst plains (I) is identical to the inf luence zones c, d, and e (I ≡ c, d, e) (Figs. 2, 4). The Trnovski gozd-Banjšice-Šentviška Gora degraded plain lies on the highest part of the Trno- vo Nappe, which is composed of carbonate rocks. This part towards the southeast is preserved only up to Mt. Streliški vrh (1266 m), while from here on it is eroded. It is appropriate, therefore, to as- sume that at the time of its formation the consid- ered level was more extensive than the surface as presented in Figure 11; according then to the definition of Stepišnik and Ferk (2023, p.12–13) it would belong to the class of corrosion plains. This is also confirmed by the modern view of their gen- esis (ibid. p.17–18). The geological significance of the Ponikve klippe on the Šentviška Gora plateau is not dis- cussed in this article. The important fact that the Šebrelje plateau represents the eastern extension of the Šentviška Gora plateau on the other side of the Idrijca Valley is also not dealt with herein. All of the above facts and assumptions require a thorough consideration of the post-thrust or post-Paleogene genesis of the Dinarides. References Arsovski, M. & Feigel, M. 1973: Neotektonika SR Slovenije. Institut za zemljotresno inženjerstvo i inženjersku seizmologiju, Univerzitet Kiril i Metodij, Skopje. Arhiv Urada za seizmologijo, Agencija Republike Slovenije za okolje / Ar- chives of Office of Seismology, Agency of the Republic of Slovenia for the Environment. Re- port OIS 73-2: 32 p. Blaškovič, I. 1991: Raspored uzdužnih, reverznih i normalnih rasjeda i konstrukcija oblika i dubina ploha podvlačenja (Disposition of the longitudinal, reverse and normal faults and the construction of the forms and depths of the underthrusting surfaces). Geol. vjesnik, 4: 247–256. 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CC Atribution 4.0 License Petrology dataset of Pliocene-Pleistocene sediments in northeastern Slovenia Podatki o petrologiji pliocensko-pleistocenskih sedimentov severovzhodne Slovenije Eva MENCIN GALE1*, Polona KRALJ1, Mirka TRAJANOVA1, Luka GALE1, 2 & Dragomir SKABERNE1 1 Geološki zavod Slovenije, Dimičeva ulica 14, SI–1000 Ljubljana, Slovenija 2 Oddelek za geologijo, Naravoslovnotehniška fakulteta, Aškerčeva 12, 1000 Ljubljana, Slovenija *corresponding author: eva.mencin-gale@geo-zs.si Prejeto / Received 21. 5. 2024; Sprejeto / Accepted 6. 6. 2024; Objavljeno na spletu / Published online 11. 6. 2024 Key words: petrological analysis, clast lithological analysis, provenance of the clasts, Pliocene-Pleistocene sediments Ključne besede: petrografska analiza, litološka analiza klastov, provenienca klastov, pliocensko-pleistocenski sedimenti Abstract This is a dataset of petrological analysis of Pliocene-Pleistocene f luvial sediments from 14 gravely samples from the Slovenj Gradec, Nazarje, Celje and Drava-Ptuj Basin (northeastern Slovenia), collected for clast lithological analysis. The petrological analysis includes description of 155 thin sections of metamorphic, volcanic, volcaniclastic, clastic and carbonate rocks. This dataset provides grounds for determining the provenance of these gravel deposits, revealing possible resedimentation processes, and serves as a tool for drainage network interpretation in the Pliocene-Pleistocene. Izvleček V članku predstavljamo podatke o petrološki analizi rečnih pliocensko-pleistocenskih sedimentov iz 14 prodnatih vzorcev iz slovenjgraškega, nazarskega, celjskega in dravsko-ptujskega bazena (severovzhodna Slovenija), ki so bili vzorčeni za namen litološke analize klastov. Petrološka analiza obsega opise 155 zbruskov metamorfnih, vulkanskih, vulkanoklastičnih, klastičnih in karbonatnih kamnin. Ti podatki predstavljajo temelj za določitev provenience obravnavanih prodnatih sedimentov, razkrivajo morebitno resedimentacijo ter so pomembni za interpretacijo razvoja rečne mreže v pliocenu in pleistocenu. GEOLOGIJA 67/1, 157-160, Ljubljana 2024 https://doi.org/10.5474/geologija.2024.008 Background This dataset was collected to perform clast lith- ological analysis of Pliocene-Pleistocene f luvial sediments in the frame of research published in Mencin Gale (2021). The dataset present in this article contributes to understanding the prove- nance of gravelly sediments deposited in Slovenj Gradec, Nazarje, Celje and Drava-Ptuj Basins us- ing clast lithological analysis. This method pro- vides grounds for determining the source of grav- el. Moreover, it serves as a tool for determination of possible re-sedimentation (e.g. from Miocene conglomerates) and drainage evolution. Clast lithological analysis is traditionally per- formed at the macroscopic level (Bridgland et al., 2012), with efficacy and statistical validity being its primary strengths (Bridgland, 1986; Walden, 2004; Gale and Hoare, 2011). However, it has been discovered that conducting petrographic analysis on thin sections of selected clasts significantly en- hances the quality and spatial resolution of prov- enance analysis (Mencin Gale, 2021; Mencin Gale et al., 2019a, 2019b, 2024). This approach provides more accurate information about the composition and source formations of the studied sediments. Detailed results and interpretations of this methodology were already published in several publications: Mencin Gale (2021), Mencin Gale et al. (2019a, 2019b, 2024). Moreover, the selected sections frow where the samples were taken were in detail discussed in Mencin Gale et al., (2019a, 2019b, 2024). Data Article 158 Eva MENCIN GALE, Polona KRALJ, Mirka TRAJANOVA, Luka GALE & Dragomir SKABERNE Experimental design, materials, and methods a) Gravel sampling We selected 14 sections in Slovenj Gradec, Nazarje, Celje and Drava-Ptuj Basins for sedi- mentological analysis and sampling (Fig. 1). The sections were selected based on length and preser- vation of the clasts (avoiding weathered sections). The sections range from 1 to 14.3 m in length (Table 1). The most suitable outcrops were found on terrace risers or within areas incised by tribu- taries. Samples of gravel were collected from the sections, which were cleaned prior to sampling. Locations of the sections (x, y, z) were acquisited with hand-held GPS device Trimble and further managed in ArcGIS Pro (ESRI). b) Clast lithological analysis (CLA) Clast lithological analysis was adapted from guidelines by Walden (2004), Lindsey et al. (2007), and Gale and Hoare (2011). Sampling for gravel involved bulk sampling of the exposed surface to avoid biasing by selecting only the most obvious clasts. The Velunja section (VE; Velenje Basin) was logged and sampled with an abseiling technique and the rest of the sections were accessible from the ground. Dry-sieving was conducted in the f ield, with only a 1.5–6 cm fraction transported to the laboratory for further analysis. Clasts smaller than 1.5 cm are mostly too weathered to allow for reliable determination of lithology. Larger clasts also allow for better observation of the texture and bulk characteristics of the rock. Each sample comprised 48–346 clasts, with precise counts provided in Table 1. A smaller num- ber of counted clasts is due to the less available material for the analysis (e.g. smaller, conglomer- ated layers). Macroscopic examination and lithol- ogy-based grouping were followed by petrological analysis. In total 2.682 clasts were examined from which 155 were selected for detailed examination in thin sections: 14 clasts from the Slovenj Gra- dec Basin, 63 from the Nazarje Basin, 13 from the Celje Basin, 32 from the Drava-Ptuj Basin, and 33 from the Velenje Basin. Fig. 1. Overview of the studied region. A: Map of Slovenia with marked investigated area. B: Locations of the selected basins and sections comprising the dataset presented in this paper. Basemap: shaded relief of the DEM (digital elevation model, Ministry of Environment & Spatial Planning, 2015). 159Petrology dataset of Pliocene-Pleistocene sediments in northeastern Slovenia c) Microscopy for determination of source stratigraphic unit We used optical polarizing microscope Opton Zeiss for microscopy in transmitted light with lenses with magnifications of 2.5×, 5×, 10×, 20×, 25×, 50×. A digital camera is attached to the mi- croscope for production of microphotographs. Bi- otic components in carbonate and mixed carbon- ate-siliciclastic rocks, grain composition in clastic rocks, and mineral associations and mineral alter- ations in metamorphic, volcanic, and volcaniclas- tic rocks determined from thin sections crucial for the determination of source stratigraphic unit of each rock type. Data description All described and deposited data are analyzed data. They are represented in several figures, ta- bles and shapefile. Fig. 1 shows locality map of the sections. Fig. 2–5 show selected photographs of 35 thin sections in the Slovenj Gradec (5), Nazarje (10), Celje (8) and Drava-Ptuj Basin (12), respectively. Figure 1: Locations of the sections where sam- ples for clast lithological analysis were collected. Figure 2: Microfacies of clasts in the Plio- cene-Pleistocene sediments from the Slovenj Gra- dec Basin in cross-polarized light. Corresponding thin sections descriptions are presented in Table 2. Abbreviations: Qtz – quartz, Mc – microcline, Pl – plagioclase, Ep – epidote, Am – amphibole, Chl – chlorite, Bt – biotite, Ms – muscovite, Grt – garnet Figure 3: Microfacies of clasts in the Plio- cene-Pleistocene sediments from the Nazarje Basin in plain- (A, B, C, D, G, H, I, J, K, L) and cross-polarized light (E, F). Corresponding thin sections descriptions are presented in Table 3. Ab- breviations: H – hyaloclasts, Lmt – laumontite, Chl – chlorite, Sme – smectite, Zeo – zeolite, Pl – plagioclase, PmL – pumice lapilli, VRF – volcanic rock fragment, Fsp – feldspar, Aug – augite, Qtz – quartz, Bt – biotite, Hbl – hornblende, M – glassy groundmass, Px – pyroxene, RF – rock fragment. Figure 4: Microfacies of clasts in the Plio- cene-Pleistocene sediments in the Celje Basin in plain- (B, C, D, E, F, G, I) and cross-polarized light (A, H). Corresponding thin sections descriptions are presented in Table 4. Abbreviations: Qtz – quartz, Ms - muscovite, CG – crystal grains, y-GS – y-shaped glass shards, VRF – volcanic lithic fragment, Fsp – feldspar, M – tuffaceous matrix, Bt – biotite, g – glassy groundmass, RF – rock fragment, Tur – tour- maline, Tur(a) - authigenic tourmaline Figure 5: Microfacies of clasts in the Plio- cene-Pleistocene sediments in the Drava-Ptuj Ba- sin in cross- (A, B, D, G, H, I) and plain-polarized light (C, E, F, J, K, L, M, N, O). Corresponding thin sections descriptions are presented in Table 5. Ab- breviations: Qtz – quartz, Qtz(m) – microcrys- talline quartz, Hbl – hornblende, Ep – epidote, Grt – garnet, Ms – muscovite, Ser – sericite, Chl – chlorite, Chl(a) – altered chloride, Op – opaque mineral, WGS – welded glass shards, Cl – col- lapsed lapilli. Locality map of sections in Shapefile (Shape- f ile 1) contains following attribute: type of shape- file, section (full name), name of the section (ab- breviations), section type, reference, where the results and interpretation are published, author of the mapping and year of mapping. Shapefile con- tains 14 data points. Shapefile 1: Location map of sections Table 1 contain dataset with listed sections in each basin; section names after village name; sec- tions’ lengths in meters; CLA (clast lithological analysis) sample; depth of collected clast lithologi- cal samples; number of counted clasts per sample; number of thin sections per sampling area; coor- dinates of the sections in EPSG Coordinate Refer- ence System Code (code: 3794); cross-reference for petrographical data (Tables 2-5 and publications) and related research article in which results and discussions were presented. Tables 2‒5 contain petrographical dataset of analyzed thin sections from the Slovenj Gradec, Nazarje, Celje and Dra- va-Ptuj Basins, respectively, including lithogroup, lithotype, thin section descriptions and prove- nance attribution. Thin sections are marked with abbreviation of the section and a consecutive num- ber. Lithogroup marks general rock classification. Lithotype represents basic rock determination. Brief petrographic description contains informa- tion about rock structure, texture, mineralogical composition, alteration, weathering, cementation, microfossils, diagenesis and, where applicable, resemblance with a certain thin section. Prove- nance was determined according to petrographic descriptions and compared with published data and maps of the geological units (Mencin Gale et al., 2019a, 2019b, 2024; Mencin Gale, 2021, and references therein). Table 1: Sections dataset Table 2: Petrography Slovenj Gradec Basin Table 3: Petrography Nazarje Basin Table 4: Petrography Celje Basin Table 5: Petrography Drava-Ptuj Basin 160 Eva MENCIN GALE, Polona KRALJ, Mirka TRAJANOVA, Luka GALE & Dragomir SKABERNE Data format Figure 1–5: Raster image (.jpeg format) Shapefile 1: ESRI shapefile, point features (.shp format) Table 1–5: Microsoft Excel file (.xlsx format) Data accessibility The analyzed data and metadata are open ac- cess data and has been deposited in DiRROS re- pository. License: CC-BY 4.0. Data and metadata are accessible using the link: Repository name: DiRROS Direct URL to data: https://dirros.openscience. si/IzpisGradiva.php?id=19042&lang=slv Acknowledgment This work was co-funded by the Slovenian Research and Innovation Agency (ARIS) in the frame of the Young Researchers programme under grant no. 38184, the postdoctoral project under grant no. Z1-50029 (EvoQ the past) and the research programme Regional Geology under grant no. P1-0011 carried out at the Ge- ological Survey of Slovenia. We would like to thank dr. Petra Gostinčar and anonymous reviewer for the com- ments that significantly improved the earlier version of the manuscript. References Bridgland, D.R. 1986: Clast Lithological Analysis. Technical Guide, 3. Quaternary Research As- sociation, Cambridge: 207 p. 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GEOLOGIJA 67/1, 161-177 , Ljubljana 2024 Poročila in ostalo - Reports and More 7. svetovni geotermalni kongres WGC 2023, Peking (Kitajska) 15. – 17. september 2023 Dušan RAJVER Geološki zavod Slovenije, Dimičeva ul. 14, SI-1000 Ljubljana, Slovenija; e-mail: dusan.rajver@geo-zs.si Pred osmimi leti so vodilni v mednarodnem geotermalnem združenju (IGA) menili, da mora postati geotermalna energija bistveno bolj pre- poznavna in vidna med svetovnimi viri energije, še posebno med obnovljivimi viri energije (OVE). Zato je Kitajska kot naslednja gostiteljica organi- zirala 7. svetovni geotermalni kongres že v sep- tembru 2023, kar je le dve leti po prejšnjem na Islandiji, ki je bil sicer najavljen za leto 2020, za- radi Covid pandemije pa je bil premaknjen za eno leto naprej in izveden večinoma virtualno (Rajver, 2021). Kongres v Pekingu je trajal le tri dni, saj so organizatorji očitno dojeli, da bo prispevkov za kongres in udeležencev iz drugih držav nekaj manj kot na prejšnjih dveh kongresih. Razloga sta najmanj dva: kongres se je namreč odvijal le dve leti za prejšnjim, nekaj vpliva pa morda imajo tudi strogi in zapleteni (in posledično odvračajoči) postopki za vstop na Kitajsko. Gostitelj kongresa je bil China National Geothermal Energy Center, organizator pa China Petrochemical Corporati- on s štirimi so-organizatorji in tremi podpornimi korporacijami (vse tri iz naftne sfere). Glavna (di- amantna) sponzorja sta bili podjetji Arctic Green Energy in Honeywell, poleg teh je bilo še deset drugih sponzorjev. Prejšnji svetovni geotermalni kongresi oziroma mednarodni geotermalni sim- poziji od leta 1970 dalje so omenjeni v prejšnjih poročilih (Rajver, 2015, 2021). Kitajska je izjemen primer, ki z leti vse bolj do- kazuje, da geotermalna energija (GE) lahko znatno prispeva k daljinskemu ogrevanju in doseže ogljič- no nevtralnost v gradbenem sektorju, četudi v vulkansko neaktivni državi. Z ogromnim povpra- ševanjem po »čistem« (ne-fosilnem) ogrevanju je postopno postavila tak geotermalni razvoj s foku- som na ogrevanju in hlajenju, kar jo je pripeljalo v rabi GE za ogrevanje in hlajenje že nekaj let na prvo mesto v svetu, kakor tudi v posredovanju novih idej za mednarodni geotermalni razvoj. Kitajska je prva glede neposredne rabe toplote iz GE, bodisi brez upoštevanja sektorja rabe plitve GE s tehno- logijo geotermalnih toplotnih črpalk (GTČ, angl. ground-source heat pumps, GSHP) ali pa skupaj s tem tipom postavitev (instalacije). Navajam števil- ke iz najnovejših svetovnih pregledov o ogrevanju in hlajenju v svetu iz GE (Manzella et al., 2023) ter proizvodnji elektrike iz GE v svetu (Gutiérrez-Ne- grín, 2023). Prispevek kitajskih avtorjev o rabi GE na Kitajskem v letu 2022 (Guo et al., 2023) namreč še vedno ni na voljo na spletni strani IGA (Internet 1). Ob koncu 2021 je dosegla kapaciteto za ogreva- nje in hlajenje iz GE na 1,33 milijard m2, vključno 530 milijonov m2 za geotermalno daljinsko ogre- vanje in 800 milijonov m2 površin, ki se ogrevajo in/ali hladijo s tehnologijo GTČ iz toplote plitvega podzemlja. V neposredni rabi za ogrevanje in hla- jenje ima Kitajska nameščeno kapaciteto naprav 100.220 MWt, iz katerih izkorišča 828.882 TJ (123.361,4 GWh, podatek za 2022), kar je 56 % svetovne izkoriščene GE za različne kategorije rabe, kar jo že 20 zaporednih let uvršča na prvo mesto. Med obsežnimi geotermalnimi aplikacijami izstopa ogrevanje in hlajenje stavb kot pomemb- na zgodba o uspehu z nameščeno zmogljivostjo 92.352 MWt in letno porabo 714.236 TJ energije. Severna Kitajska, predvsem pet severnih provinc in mest Hebei, Henan, Shandong, Shaanxi in Ti- anjin, ki se zanašajo na bogate geotermalne vire v sedimentnih bazenih, se je postopoma razvila v glavno območje z daljinskim ogrevanjem iz hidro- geotermalnih virov. Vse to je zelo podprto s poli- tiko čistega ogrevanja pozimi v severni regiji in z ustreznim davkom za geotermalne vire. Poleg tega se je ogrevanje iz hidrotermalnih virov razvilo tudi v severnih in alpskih regijah ter nekaterih provin- cah na jugu (Heilongjiang, Jilin, Liaoning, Notra- nja Mongolija, Xinjiang, Gansu, Ningxia, Qinghai, Tibet, Jiangsu, Anhui in Hubei). Sistemi GTČ so večinoma razširjeni v ravninah vzhodne Kitajske, med katerimi je najbolje razvit Bohajski rob, dru- ga regija pa je srednji in spodnji tok ravnic reke Jangce. Druge dejavne kategorije rabe so: kmetij- stvo (rastlinjaki, akvakultura) in predelava hrane, 162 industrijska procesna toplota, ter zdravje, rekrea- cija in turizem (bazenski kompleksi). - Seveda pa Kitajska nima takih geoloških danosti za proizvo- dnjo elektrike iz GE kot jo imajo druge države iz visokoentalpijskih geotermalnih sistemov, zato v njenih elektrarnah nameščena kapaciteta znaša le 45,1 MWe, iz katere je proizvedla 131,2 GWh elek- trike (Guo et al., 2023; v: Gutiérrez-Negrín, 2023). Tokratni kongres je zaradi prej omenjenih ra- zlogov težko primerjati s tistim na Islandiji leta 2020+1 ali tistim v Avstraliji 2015. Prisotno je bilo okrog 900 udeležencev, kar je precej manj kot na prejšnjih kongresih, in od tega jih je bilo manj kot polovico iz drugih držav. Potekal je le na licu mes- ta in ne virtualno. Za kongresni zbornik je bilo tik pred kongresom sprejeto okrog 765 prispevkov, precej manj kot na prejšnjih kongresih, in niso bili predani udeležencem kongresa v nobeni združe- ni obliki zbornika (USB ali spletna povezava na vse prispevke, CD na prejšnjih kongresih), kot je bila praksa na vseh prejšnjih svetovnih kongresih. Organizatorji so namreč dopustili možnost, da so avtorji lahko svoje prispevke še po kongresu do- polnili in popravili ter jih poslali na uradno sple- tno stran kongresa še do 13. okt. 2023. Ni znano koliko prispevkov je bilo še naknadno poslano, se- daj (stanje 22. dec. 2023) je na spletni strani IGA naloženo še vedno le 436 prispevkov. V tabeli 1 so vse sekcije (v angl. in slov.), s števi- lom sprejetih prispevkov po posameznih sekcijah, kakor je bilo navedeno na spletni strani kongresa le nekaj dni pred kongresom. Session Sekcija Število prispevkov Predstavljeni prispevki govorno poster Advanced geothermal Napredna tehnologija in pristopi (v geotermiji) 18 Business strategies (Green Finance) Poslovne strategije (financiranje v OVE) 7 4 (GF) Case histories Primeri (raziskav in/ali rabe GE) 7 Corrosion in geothermal systems Korozija v geotermalnih sistemih 5 Country updates Poročila držav o rabi GE 14 Direct use: local solutions Neposredna raba: lokalne rešitve 5 Direct use: miscellaneous Neposredna raba: razno 6 Direct use: rural-urban use Neposredna raba: na podeželju-v mestih 5 Direct use: wells exploitation Neposredna raba: vrtine v izkoriščanju 5 District heating: sustainability Daljinsko ogrevanje: trajnost 4 District heating: technology Daljinsko ogrevanje: tehnologija 4 Drilling & completion technology Tehnologija vrtanja & dokončanja del (druge tehno- loške naprave) 28 14 Education Izobraževanje (v geotermiji) 4 Enhanced geothermal systems Izboljšani geotermalni sistemi (EGS) 19 Energy cost & efficiency Strošek energije & učinkovitost 5 Environmental aspects Okoljski vidiki 4 Exploration: exploration methods Raziskave: raziskovalne metode 6 Exploration (in Americas & Africa) Raziskave (v Amerikah & Afriki) 6 Exploration (in China & Indonesia) Raziskave (na Kitajskem & v Indoneziji) 12 Exploration (in Eurasia) Raziskave (v Evropi & Aziji) 5 Exploration (remote sensing & borehole imaging) Raziskave (daljinsko zaznavanje & slikanje vrtin) 6 Field management Upravljanje z geotermalnim poljem 6 Geochemistry low temperature fracture hotsprings Geokemija: nizko-temperaturni razpoklinski vroči izviri 6 Geochemistry experiment mineral Geokemija: poskusi, minerali 4 Geochemistry high temperature Geokemija: visoko-temperaturno okolje 6 Geochemistry sedimentary Geokemija: sedimentno okolje 5 Geology Geologija 43 Geophysics Geofizika 35 Tabela 1. Seznam vseh sekcij na kongresu in število najavljenih predstavitev po sekcijah. 163 Geothermal closed loop Geotermični sistemi na zaprti krogotok 10 Geothermal development & utilization & Cities Geotermalni razvoj & izkoriščanje GE & Mesta 23 Geothermal Geotermalni (razno) 14 Heat storage Shranjevanje toplote 5 Hydrogeology Hidrogeologija 9 Hydrothermal accumulation mechanism & Resource assessment Mehanizem hidrotermalne akumulacije & Ocena vi- rov 7 Injection technology Tehnologija reinjektiranja 4 Integrated energy systems & Cascaded uses Integrirani energijski sistemi & Kaskadne rabe 7 International collaboration Mednarodna sodelava 6 Life cycle analysis Analiza življenjskega cikla (LCA) 3 Markets Trženje geotermije (opreme, toplote) 9 Minerals, metals & hydrogen Minerali, kovine & vodik (iz GE) 6 Oil & gas Toplota iz naftnih /plinskih polj 7 9 Policy, legal & regulatory aspects Politika, pravni in regulativni vidiki 6 2 Power generation Proizvodnja elektrike (iz GE) 6 Power generation (Prospective sites) Proizvodnja elektrike (perspektivne lokacije) 5 Production engineering, steam gathering systems Proizvodni inženiring, sistemi zbiranja (geotermalne) pare 5 Research & Development: drilling & completion Raziskave & razvoj: vrtanje & dokončanje 14 Research & Development: field & production tech- nology Raziskave & razvoj: tehnologija geotermalnega polja & proizvodnje 26 Research & Development: geoscience Raziskave & razvoj: geoznanost 80 Research & Development: geothermal systems Raziskave & razvoj: geotermalni sistemi 38 Reservoir engineering Inženiring (geotermalnih) rezervoarjev 23 Resource assessment Ocena (geotermalnih) virov 6 Risk mitigation Blaženje rizika 5 Scaling in geothermal systems Luščenje (odlaganje kotlovca) v geotermalnih siste- mih 14 Societal & cultural aspects Družbeni in kulturni vidiki 5 Supercritical geothermal Superkritični geotermalni viri 7 Sustainability & climate change Trajnost & klimatske spremembe 6 16 Technology & Innovation - Big data & data analytics Tehnologija & inovacije - Veliki podatki & analitika podatkov 6 Technology & Innovation - intelligent computing & AI Tehnologija & inovacije - inteligentno računalništvo & umetna inteligenca 7 Technology & Innovation Tehnologija & inovacije 10 Technology & Innovation - software for geothermal applications Tehnologija & inovacije - programska oprema za geo- termalne aplikacije 6 Top sides - case studies: heat pumps Vrhunski dosežki - študije primerov: toplotne črpalke 6 Top sides - deep BHEs Vrhunski dosežki - globoke geosonde 6 Top sides - economics, exploration & financing Vrhunski dosežki - ekonomija, raziskovanje & finan- ciranje 4 Top sides - models & analysis of pilot sites Vrhunski dosežki - modeli & analiza pilotnih lokacij 7 Top sides Vrhunski dosežki 19 UNFC sessions UNFC sekcije 3 Water use Raba (termalne) vode 3 SKUPAJ: 765 487 278 Opombe: EGS=Enhanced Geothermal System; GE=geotermalna energija; UNFC=United Nations Framework Classifica- tion for resources; BHE=Borehole Heat Exchanger; GF=green finance. 164 Skupno je do pričetka kongresa prispelo 765 prispevkov, in okvirno toliko naj bi bilo na kon- gresu tudi predstavitev (od tega 278 posterjev) v 67 sekcijah. Seveda pa se je na samem kongresu izkazalo, da precej predavateljev, predvsem iz dru- gih držav, sploh ni prispelo na kongres (po okvirni oceni >10 %), tako da nekatere predstavitve niso bile izvedene. Raznolikost v temah prispevkov je rezultat širitve svetovne dejavnosti v raziskavah in rabi geotermalne energije, kakor tudi vključenosti ge- otermalne energije v različnih vejah dejavnosti oziroma družbe. Iz prevladujočih sekcij po šte- vilu prispevkov se opazi, kam so usmerjeni glav- ni napori v raziskavah, razvoju in uveljavljanju geotermalne energije: raziskave in razvoj (štir je različni vidiki: 158, od tega geoznanost 80, ge- otermalni sistemi 38, tehnologija geotermalnega polja in proizvodnje 26), geologija (43), tehnolo- gija vrtanja in dokončanja del (42), vrhunski do- sežki (različni vidiki: 42), geof izika (35), tehno- logija in inovacije (različni vidiki: 29), raziskave po regijah in raziskovalne metode (29), geoter- malni razvoj in izkoriščanje geotermalne energi- je (23), inženiring (geotermalnih) rezervoarjev (23), trajnost in klimatske spremembe (22), ge- okemija (štir je različni vidiki: 21), neposredna raba toplote (različni vidiki: 21), EGS (19), na- predna tehnologija v geotermiji (18). Glede na prejšnje kongrese so nekatere dejavnosti prišle tokrat bolj v ospredje, vseeno pa so posredne in površinske metode (geof izika, geokemija in geo- logija) še naprej zelo pomembne v raziskavah in upravljanju geotermalnih virov. Z namenom bolj uveljaviti geotermalno energijo med OVE je vi- den prispevek sekcij trajnost, trženje geotermije, polit ika in regulativni vidiki. Številni prispevki o raziskavah kažejo na dejavno iskanje novih virov v raznih državah sveta. Izpostavim lahko še nekaj zanimivih prispevkov v sekciji Vrhunski dosežki, kot so primeri z uporabo toplotnih čr- palk, primeri z globokimi geosondami ter modeli in analiza pilotnih lokacij. Pod okriljem kongresa so se med kongresom odvijali naslednji dogodki: Global geothermal collaboration forum, China-Iceland geothermal technology exchange forum, Geothermal youth fo- rum, IGA standard release. V kongresnem centru se je istočasno odvijala razstava opreme za razi- skave in razvoj geotermalne energije (Geothermal development technology and equipment exhibit i- on) z močnim deležem kitajskih podjetij (proizvo- dnja opreme za vrtine, cevovode, toplotne posta- je, elektrarne, itd.) v geotermalnih raziskavah in razvoju ter izkoriščanju geotermalne energije. V ponudbi kongresa je bila tudi izvedba štirih eks- kurzij (2-dnevne do 6-dnevne), vse v osrednji in jugozahodni del vzhodne polovice države. Plenarna predavanja na otvoritvi (L.C. Gutiér- rez-Negrín o napredku v proizvodnji elektrike iz GE v svetu, A. Manzella o ogrevanju in hlajenju iz geotermalne energije (GE) v svetu ter X. Guo o razvoju kitajske geotermalne industrije) so po- kazala vztrajno rast v geotermalnem razvoju. Za ta kongres je o ogrevanju in hlajenju iz GE poro- čalo 38 držav, za 50 držav so pridobljeni podatki iz drugih virov. Torej se je ogrevanje in hlajenje ob koncu leta 2022 odvijalo v 88 državah, enako kot tri leta prej (Manzella et al., 2023). Skupna nameščena kapaciteta za ogrevanje in hlajenje iz GE znaša 173.303,2 MWt, kar je porast za 60 % glede na številko poročano za WGC 2020+1. Na ta znaten napredek večinoma vplivajo poročane številke o veliki širitvi rabe GE za ogrevanje in hlajenje na Kitajskem. Skupna svetovna raba GE je znašala 1.476.312,0 TJ (410 TWh), kar je po- rast za 44 % glede na poročano za WGC 2020+1 (Lund & Toth, 2021). Tabela 2 povzema oboje po celinah (Manzella et al., 2023). Pomembna zna- čilnost poročanja, kot ga podajajo Manzella in sodelavci (2023), je revidirana klasif ikacija ka- tegorij rabe GE za ogrevanje in hlajenje. Katego- rizacija je bila poenostavljena in zdaj obsega pet pomembnih uporab geotermalne toplote, in sicer (I) kmetijstvo in predelava hrane, (II) industrij- ska procesna toplota, (III) zdravje, rekreacija in turizem, (IV) ogrevanje in hlajenje zgradb, in (V) druge uporabe. Strokovnjaki so se strinjali, da je treba kategorijo GTČ (plitva geotermija) obravna- vati kot vrsto naprave in ne kot kategorijo samo po sebi. Številke zanjo so uvrščene večinoma v rabo »ogrevanje in hlajenje zgradb«. Prva novost poročila Manzelle in sodelavcev (2023) je v termi- nologiji in kategorizaciji, začenši s sklicevanjem na toplotno uporabo geotermalne toplote. Geo- termalna toplota se pogosto imenuje „neposredna uporaba“. Vendar to ni običajno ime zunaj geoter- malne industrije. Strokovnjaki so se strinjali, da je „ogrevanje in hlajenje“ najprimernejše ime za ta sektor. Pri izbiri so odločali ozaveščenost ob- činstva (uporabno zunaj geotermalne industrije), inkluzivnost (plitva in globoka, nizka in visoka entalpija itd.) in celovitost (vključno z uporabo GTČ kot vrste tehnologije skupaj z drugimi vrsta- mi). Kot predlog za opredelitev sektorja je ogre- vanje in hlajenje „uporaba toplotne energije, ki se nahaja v podzemlju ali naravno dviga na površi- no tal, za katerikoli namen, razen za proizvodnjo električne energije“. 165 Celina (štev. držav) MWt TJ/leto GWh/leto Afrika (11) 160,71 3.713,78 1.031,61 Amerika (17) 24.506,46 191.540,82 53.205,78 Azija (17) 105.095,70 877.957,20 243.877,00 Evropa (36) 37.051,68 291.237,47 80.899,30 Oceanija (3) 820,60 15.352,02 4.264,45 Transcelinske (4) 5.668,05 96.510,72 26.808,53 SKUPAJ (88) 173.303 1.476.312 410.087 Stopnje rasti instalirane moči in letne rabe GE za zadnjih 28 let so povzete na slikah 1 in 2. Ka- tegorija z najbolj izrazitim porastom v tem obdob- ju je »ogrevanje in hlajenje zgradb«. Slika 1 jasno kaže znaten porast te kategorije v nameščeni kapa- citeti, ki je precej podkrepljena z naraščajočim šte- vilom sistemov z enotami GTČ (izkoriščanje plitve GE), vključno za industrijske rabe. Znaten porast kategorije ogrevanja in hlajenja zgradb, viden na sliki 2, je prvenstveno posledica močne širitve to- vrstne rabe na Kitajskem. Kitajska, ZDA, Švedska, Nemčija in Turčija so države z največ nameščene kapacitete (MWt) za ogrevanje in hlajenje iz GE (vse kategorije rabe), in v teh državah je kar 80 % svetovne kapacite- te, medtem ko so države z največ izkoriščene GE na letni ravni Kitajska, ZDA, Turčija, Švedska in Islandija (Tabela 3). 0 20.000 40.000 60.000 80.000 100.000 120.000 140.000 160.000 180.000 2023 2020 2015 2010 2005 2000 1995 Leto Svetovna nameščena kapaciteta (MWt) za ogrevanje in hlajenje iz geotermalne energije Kmetijstvo in predelava hrane Industrijska procesna toplota Zdravje, rekreacija in turizem Ogrevanje in hlajenje zgradb Druge rabe (taljenje snega, idr.) Tabela 2. Povzetek podatkov o ogrevanju in hlajenju v svetu po celinah (za leto 2022). Sl. 1. Nameščena kapaciteta (MWt) za ogrevanje in hlajenje (porazdeljena po kategorijah) kot je poročano na svetovnih geotermalnih kongresih od 1995 do 2023 (Lund & Toth, 2021; Manzella et al., 2023). Država Kapaciteta, MWt Država Energija, TJ/leto Kitajska 100.220 Kitajska 828.882 ZDA 20.712 ZDA 152.809 Švedska 7.280 Turčija 85.000 Nemčija 5.381 Švedska 67.680 Turčija 5.113 Islandija 35.615 Tabela 3. Vodilne države v sve- tu v izkoriščanju geotermalne energije za ogrevanje in hla- jenje. Ob koncu leta 2021 so bile delujoče geotermal- ne elektrarne samo v 31 državah, s skupno močjo 16.260 MWe, to je le 0,16 % vse inštalirane moči vseh elektrarn na svetu, ki je bila 10.216.390 MWe. Geotermalne elektrarne so postavljene na 197 geotermalnih poljih s 671 posameznimi agregati (stanje v dec. 2021). Skoraj 38 % teh enot je tipa z momentnim vparevanjem (angl. f lash) s skupno močjo 9.129 MWe (52,6 % od skupne moči), sle- dijo binarne enote tipa ORC z 21,7 % instalirane moči. Izbrani niz držav z geotermalno proizvodnjo elektrike še naprej vodijo ZDA, sledijo Indonezi- ja, Filipini in Turčija. Vse države so v letu 2021 proizvedle 96.562 GWh električne energije pri po- prečnem letnem faktorju zmogljivosti 68 %, kar je predstavljalo 0,35% svetovne proizvodnje električ- ne energije (27.834,7 TWh) in 0,90 % vse »čiste« električne energije v svetu (10.731,3 TWh). Čista energija je definirana kot proizvedena elektrika iz nizko-ogljičnih virov, kar v osnovi vključuje vse OVE in nuklearno energijo. V vsaj sedmih državah električna energija geotermalnega izvora predsta- vlja več kot 10 % vse proizvedene elektrike, na čelu s Kenijo, Islandijo in Salvadorjem. Praktično vseh 197 delujočih geotermalnih polj izkorišča vire iz hidrotermalnih konvencionalnih rezervoarjev, z oceno 3700 proizvodnih vrtin z letno poprečno proizvodnjo skoraj 3 MWh na vrtino. Stvari bi lahko bile podobne v naslednjih nekaj letih, če se bo trenutni trend nadaljeval, vendar se lahko vse spremeni zaradi svetovne nujnosti ohranjanja glo- balnega segrevanja pod pragom 1,5 °C v nasled- njih letih (Gutiérrez-Negrín, 2023). 0 200.000 400.000 600.000 800.000 1.000.000 1.200.000 1.400.000 1.600.000 2023 2020 2015 2010 2005 2000 1995 Leto Svetovna letna raba (TJ/leto) geotermalne energije za ogrevanje in hlajenje Kmetijstvo in predelava hrane Industrijska procesna toplota Zdravje, rekreacija in turizem Ogrevanje in hlajenje zgradb Druge rabe (taljenje snega, idr.) Sl. 2. Letna raba geotermalne energije (TJ/leto) za ogrevan- je in hlajenje (porazdeljena po kategorijah) kot je poročano na svetovnih geotermalnih kon- gresih od 1995 do 2023 (Lund & Toth, 2021; Manzella et al., 2023). 0 20.000 40.000 60.000 80.000 100.000 120.000 0 2.000 4.000 6.000 8.000 10.000 12.000 14.000 16.000 18.000 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 Pr oi zv ed en a el ek tr ik a, G W h Ka pa cit et a, M W e Kapaciteta geotermalnih elektrarn in proizvedena elektrika v svetu iz GE (Poročano v letih 1950 - 2023; Ni podatkov o proizvedeni elektriki pred l. 1980) Kapaciteta, MW Proizvedena elektrika, GWh Sl. 3. Kapaciteta geotermalnih elektrarn in njihova proizvede- na elektrika v svetu med leto- ma 1980 in 2023. Proizvedena elektrika v letih 1980 in 1985 je le ocenjena (Gutiérrez-Ne- grín, 2023). 166 167 Po podatkih kot jih navaja Gutiérrez-Negrín (2023), je letna rast proizvedene geotermalne ele- ktrike (7,4-krat) višja od rasti celotne svetovne proizvodnje elektrike v istem obdobju (5,6-krat, s 5.633 na 28.254 TWh), pa tudi od rasti nizko- ogljične proizvedene električne energije (4,6-krat, z 2438 na 11.143 TWh). To seveda pomeni, da je geotermalna industrija rastla nekoliko hitreje kot proizvodnja elektrike na splošno in zlasti industri- ja čiste energije, kar se zdi protislovno. Vendar pa tudi pojasnjuje, zakaj se je delež geotermalne ener- gije tako v skupni kot v čisti proizvodnji elektrike v teh desetletjih povečeval z 0,23 % oziroma 0,54 % na 0,34 % oziroma 0,87 %. Vsekakor gre za majhno globalno povečanje, vendar je bistveno v državah, kjer geotermalna energija prispeva pomemben del portfelja električne energije. V izkoriščanju geotermalne energije je v Slo- veniji ob koncu 2022 znašala nameščena zmoglji- vost naprav za neposredno rabo 318 MWt, letna izkoriščena geotermalna energija pa 1847 TJ (ali 513 GWh) (Rajver et al., 2023a, 2023b), vključno s prispevkom geotermalnih toplotnih črpalk (GTČ) v koriščenju toplote plitvega podzemlja za ogreva- nje in hlajenje. Prispevek sektorja GTČ za ogreva- nje in/ali hlajenje prostorov je v letu 2022 znašal 260 MWt oziroma 1295 TJ (360 GWh). Različne kategorije rabe pa zajemajo: ogrevanje individual- nih prostorov in pripravo sanitarne vode, daljin- sko ogrevanje, klimatizacijo/hlajenje, ogrevanje rastlinjakov, kopanje in plavanje z balneologijo, taljenje snega ter ogrevanje in/ali hlajenje s teh- nologijo GTČ. Z Geološkega zavoda Slovenije je bil na kongre- su prisoten le pisec tega poročila s prispevkom v sekciji Country updates (Rajver et al., 2023a). V drugih prispevkih strokovnjaki iz Slovenije tokrat niso bili nikjer prisotni. Naslednji svetovni geo- termalni kongres bo že junija 2026 v Kanadi (Cal- gary), še prej pa bo leta 2025 naslednji evropski geotermalni kongres v Švici (Zürich). Sl. 4. Notranjost geotermalne elektrarne z močjo 280 kW z ORC tipom turbine v Tianzhenu (SV od Datonga), Shanxi demonstration base. Sl. 5. Datong Volcanic group GeoPark, VSV od Datonga. 168 Viri Guo, X., Dang, L., Han, Z. & Guo, D. 2023: High-Quality Development of China‘s Geo- thermal Industry – China National Report of the 2023 World Geothermal Conference. Pro- ceedings, World Geothermal Congress 2023, 15-17 Sept. 2023, Beijing, China. Gutiérrez-Negrín, L.C. 2023: Worldwide Geother- mal Power 2020-2023 Update Report. Pro- ceedings, World Geothermal Congress 2023, Sept. 2023, Beijing, China, 36 p. Lund, J.W. & Toth, A.N. 2021: Direct utilization of geothermal energy 2020 worldwide review. Geothermics, 90. https://doi.org/10.1016/j.ge- othermics.2020.101915 Manzella, A., Cannone, E., Galione, M.R. & Trumpy, E. 2023: Geothermal Heating and Cooling Production, 2023 Worldwide Review. Proceedings, World Geothermal Congress 2023, 15-17 Sept. 2023, Beijing, China, 25 p. Rajver, D. 2015: 5. Svetovni geotermalni kongres v Melbournu (Avstralija). Geologija, 58/2: 263- 264, Ljubljana. Rajver, D. 2021: 6. Svetovni geotermalni kongres WGC 2020+1, Reykjavik (Islandija). Geologija, 64/2: 294-298, Ljubljana. Rajver, D., Rman, N., Lapanje, A. & Prestor, J. 2023a: Geothermal Country Update Report for Slovenia, 2020-2022. Proceedings, World Geothermal Congress 2023, 15-17 Sept. 2023, Beijing, China, IGA, 10 p., 3 tables. Rajver, D., Pestotnik, S., Rman, N., Hribernik, J., Srša, A., Lapanje, A., Prestor, J. & Adrinek, S. 2023b: Pregled rabe geotermalne energije v Sloveniji v letu 2022 in način pridobivanja po- datkov o trgu geotermalnih toplotnih črpalk. Mineralne surovine v letu 2022, Geološki za- vod Slovenije, Ljubljana: 154-173. Internet 1: Geothermal Paper Database - Interna- tional Geothermal Association (lovegeother- mal.org) 169 Poročilo slovenskega nacionalnega odbora za geoznanosti in geoparke (IGGP) za leto 2023 Matevž NOVAK1, 2 1Geološki zavod Slovenije, Dimičeva ul. 14, SI-1000 Ljubljana, Slovenija; e-mail: matevz.novak@geo-zs.si 2Slovenski nacionalni odbor za geoznanosti in geoparke Mednarodni program za geoznanost in geopar- ke (International Geoscience and Geoparks Pro- gramme – IGGP) od leta 2015 združuje dva, prej ločena programa. To sta Mednarodni geoznanstve- ni program (International Geoscience Programme – IGCP) in program Unescovih Globalnih geopar- kov (Unesco Global Geoparks - UGGp). Prvi je bil ustanovljen že leta 1972 v sodelovanju Unesca in Mednarodne zveze geoloških znanosti (Inter- national Union of Geological Sciences – IUGS). Ustanovljen je bil z imenom International Geolo- gical Correlation Programme (Mednarodni geo- loški korelacijski program) in je bil zelo usmerjen v mednarodne stratigrafske korelacije. Vanj so bili močno vpeti tudi slovenski raziskovalci. Leta 2005 je bil IGCP program prestrukturiran in preimeno- van v International Geoscience Programme, krati- ca pa je ostala. Od leta 2013 ima IGCP podnaslov »Geoznanost v službi družbe« in je usmerjen v spodbujanje trajnostne rabe naravnih virov, ener- getskega prehoda, zmanjševanja tveganj geoloških nevarnosti ter ohranjanja geopestrosti in geološke dediščine. Program danes povezuje več kot 10.000 geoznanstvenikov iz več kot 150 držav, ki z eks- pertizami in mreženjem postavljajo temelje pri- hodnosti našega planeta. Program se izvaja skozi IGCP projekte, razdeljene v pet glavnih tematskih sklopov: Zemljini viri, Globalne spremembe in evolucija življejna, Geološko pogojene nevarnosti, Hidrogeologija in Geodinamika. V Sloveniji je bil leta 1992 ustanovljen Sloven- ski nacionalni odbor IGCP, ki se je leta 2015 prei- menoval v Nacionalni odbor IGGP. Deluje kot stro- kovno in posvetovalno telo Slovenske nacionalne komisije za Unesco (SNKU). Na redni letni seji Nacionalnega odbora IGGP, 18. 12. 2023, so bili za člane v novem štiriletnem mandatu imenovani predstavniki inštitucij in po- samezniki: - dr. Matevž Novak, Geološki zavod Slovenije (GeoZS), predsednik NO - doc. dr. Luka Gale, UL, Naravoslovno tehniš- ka fakulteta, Oddelek za geologijo in GeoZS, tajnik NO - dr. Mirka Trajanova, upokojena sodelavka GeoZS - dr. Miloš Bavec, GeoZS - mag. Suzana Fajmut Štrucl, Geopark Karavanke - doc. dr. Špela Goričan, Paleontološki inštitut Ivana Rakovca, ZRC SAZU - dr. Mateja Gosar, GeoZS - Marjutka Hafner, Urad za UNESCO - izr. prof. dr. Martin Knez, Inštitut za razisk- ovanje krasa, ZRC SAZU - doc. dr. Tea Kolar-Jurkovšek, GeoZS - pridr. prof. dr. Marko Komac, samostojni pod- jetnik - Bojan Režun, Geopark Idrija - Martina Stupar, Zavod RS za varstvo narave (ZRSVN) - dr. Katica Drobne, upokojena sodelavka Pale- ontološkega inštituta Ivana Rakovca, ZRC SAZU, častna članica - zaslužni prof. dr. Simon Pirc, upokojeni sodelavec UL, NTF, Oddelek za geologijo, čast- ni član - izr. prof. dr. Nastja Rogan Šmuc, UL, NTF, Oddelek za geologijo - doc. dr. Petra Žvab Rožič, UL, NTF, Oddelek za geologijo - doc. dr. Aleš Šoster, UL, NTF, Oddelek za geologijo V letu 2023 je Nacionalni odbor IGGP koordi- niral aktivnosti, ki so vključevale sodelovanje v IGCP projektih in dveh delovnih skupinah IUGS ter izvajanje programov dveh UNESCO Globalnih geoparkov, Idrija in Karavanke/Karawanken in Mednarodnega dneva geopestrosti. Glavnino projektov je obsegal sklop IGCP s po- udarkom na prioritetah Unesca. Težišče dela je bilo na terenskih raziskavah, laboratorijski analitiki, mreženju in pripravi ter objavi rezultatov v domačih in tujih mednarodno priznanih znanstvenih revijah. Raziskovalci so težili k čim večji vpetosti v medna- rodno sodelovanje, popularizacijo geoznanosti, pre- nos znanja na mlade ter širšo zainteresirano javnost in prenos dobrih praks med geoparki na mednaro- dnem nivoju. Povezovanje je potekalo preko spletnih in javnih medijev ter mednarodnih srečanj. Poleg temeljnih znanj prinašajo raziskovalni projekti neposredno uporabno vrednost na podro- čju vodnih virov, geotermalne energije, varstva okolja in naravne dediščine ter geološko pogojenih 170 Preglednica 1. Pregled projektov IGGP in nosilcev posameznih nalog v letu 2023. Zap. št Projekti Nosilci projektov, inštitucije 1. IUGS/IAGC: Global Geochemical Baselines M. Gosar, GeoZS 2. IUGS/IFG: Initiative on Forensic Geology M. Gaberšek, GeoZS 3. IGCP 692: Geoheritage for Geohazard Resilience K. Ivančič, GeoZS 4. IGCP 685: Geology for Sustainable Development E. Mencin Gale, GeoZS 5. IGCP 636: Geothermal resources for energy transition: direct uses and clean and re-newable base-load power N. Rman, GeoZS 6. IGCP 684: The Water-Energy-Food and Ground-water Sustainability Nexus M. Janža, GeoZS 7. IGCP 710: Western Tethys meets Eastern Tethys – geodynamical, paleoceanographi-cal and paleobiogeographical events K. Drobne, ZRC SAZU, L. Gale, NTF, P. Miklavc, NTF 8. IGCP 652: Reading geologic time in Paleozoic sedimentary rocks: the need for an inte-grated stratigraphy M. Dolenec, NTF 9. IGCP 683: Pre-Atlantic geological connections among northwest Africa, Iberia and eastern North America: Implications for continental configurations and economic resources A. Šoster, NTF 10. IGCP 737: SMART geology for better community P. Žvab Rožič, NTF 11. Geopark Idrija B. Režun, Zavod za turizem Idrija 12. Geopark Karavanke, Slovenija-Avstrija S. Fajmut Štrucl, Podzemlje Pece 13. Obeleževanje Mednarodnega dneva geopestrosti M. Stupar, ZRSVN nevarnosti. Slovenski raziskovalci so v letu 2023 sodelovali v osmih IGCP projektih. Nadaljevale so se aktivnosti v dveh delovnih skupinah IUGS in dveh UNESCO Globalnih geoparkih. Projekti in nosilci nalog so prikazani v Preglednici 1. V delovnih skupinah IUGS/IACG in IUGS/IFG slovenski raziskovalci sodelujejo pri ugotavljanju naravnega geokemičnega ozadja in razločevanju med geološkimi materiali naravnega in antropo- genega izvora. Projekti IGCP 652, 683 in 710 so temeljne na- rave. Na podlagi izsledkov terenskih raziskav in laboratorijskih analiz se v teh projektih usklajuje stratigrafsko zaporednje kamnin, preko katerega se ugotavljajo razmere in dogajanja v okolju in nje- gove spremembe v geološki zgodovini. Nadgradnja geoloških modelov z novimi ugotovitvami je nujna za ugotavljanje geološkega razvoja posameznih ob- močij, korelacije s sosednjimi območji, usmerjanje nadaljnjih raziskav, predvsem pa za načrtovanje rabe prostora. Projekti IGCP 636, 684 in 685 so aplikativne narave. Obravnavajo vire geotermalne enrgije za prehod na pridobivanje energije iz obnovljivih vi- rov, vodne vire za zagotavljanje pitne vode in vode za potrebe kmetijstva ter proučevanje sedimentov in sedimentacijskih procesov v obdobju kvartarja, ki so pomembni z družbeno-ekonomskega vidika, saj dajejo smernice za umeščanje infrastrukture v prostor, potresno varnost ter pridobivanje novih virov pitne vode. Projekta IGCP 692 in 737, ter aktivnosti obeh Unescovih Globalnih geoparkov, Idrije in Kara- vank/Karawanken, združujejo interdisciplinarna znanja na osnovi geoznanosti. Njihov cilj je kre- pitev znanja o vseh vidikih geološke dediščine s širjenjem lastnih izkušenj z vzpostavljanjem in upravljanjem območij Unescove svetovne dediš- čine, geoparkov in drugih zavarovanih območij geološke dediščine. Oba geoparka sta uspešno opravljala vlogo informiranja, izobraževanja in ozaveščanja šolajoče se mladine in zainteresira- ne javnosti. S ciljem nadaljevanja aktivnosti za vzpostavitev upravljavskega načrta in trajnostne- ga razvoja čezmejnega geoparka Kras-Carso je bil v sodelovanju z italijanskimi partnerji prijav- ljen projekt INTERREG IT-SI KRAS-CARSO II – Skupno upravljanje in trajnostni razvoj območja Matičnega Krasa. Oddaja aplikacije za članstvo v Unescovi mreži Globalnih geoparkov se je žal za- maknila za eno leto in je načrtovana v letu 2024. Za obeležitev 2. Mednarodnega dneva geope- strosti v letu 2023 je bilo s koordinacijo Zavoda RS za varstvo narave in Nacionalnega odbora IGGP izvedenih več promocijskih aktivnosti in preda- vanj z namenom širjenja novice o Mednarodnem dnevu geopestrosti s poudarkom pomena tega dne- va. Osrednji dogodek obeležitve je bil 6. oktobra v prostorih Glasbene šole Litija - Šmartno z okroglo mizo »Raba minaralnih surovin in njihov pomen za geopestrost« ter obiskom Rudnika Sitarjevec. 171 Poročilo o aktivnostih Slovenskega geološkega društva v letu 2023 Astrid ŠVARA Inštitut za raziskovanje krasa ZRC SAZU, Titov trg 2, SI–6230 Postojna, Slovenija; e-mail: astrid.svara@zrc-sazu.si V letu 2023 je bila glavna naloga vodstva društva sprememba društvenega statuta. Ker je zaradi posodobitve društvenih aktivnosti postal statut mestoma neskladen z delovanjem društva, je bila popolna prenova temeljnega akta neizo- gibna. Slednje smo opravili skladno z Zakonom o društvih (Uradni list RS št. 64/11-ZDru-1-UPB2), z Zakonom nevladnih organizacij (Uradni list RS št. 21/18) in s posvetovanjem z referentkama z Upravne enote Ljubljana ter Ministrstva za vzgojo in izobraževanje, kjer je Slovensko geološko dru- štvo (SGD) registrirano. Sprememba statuta je v ožji skupini potekala aktivno in angažirano celo leto. Statut SGD je skupščina soglasno sprejela na seji 13. 3. 2024. Po potrditvi je bil poslan v pregled in overitev na UE LJ. Statut je dostopen na spletni strani društva. Tik pred predhodno sejo skupščine se je pri- petila nezgoda pri urejanju spletne strani – stran je v minuti postala nepregledna, številni podatki so ob sesutju strani bili tudi izgubljeni. V ožjem izvršnem odboru smo sprejeli odločitev, da sple- tno stran iz precej zahtevne in skrbniku nepri- jazne domene »Joomla« s pomočjo strokovnjaki- nje prestavimo na strežnik »Wordpress«. Slednji je enostavnejši za uporabo in upravljanje. Preno- vljena spletna stran društva je bila predstavljena na skupščine in je dostopna na naslovu: www.slo- venskogeoloskodrustvo.si. Poleg nove spletne grafične podobe društva, smo izdelali tudi dve reklamni roll-up stojali – v slovenskem in angleškem jeziku. Stojali sta pri- merni za uporabo na različnih dogodkih, kjer so- deluje SGD. Vsi, ki bi si želeli stojalo izposoditi, lahko to storijo s sporočilom predsednici društva. V začetku decembra 2023 je na Naravoslovno- tehniški fakulteti (NTF), na Oddelku za geologijo, v soorganizaciji z društvom potekalo 26. posveto- vanje slovenskih geologov. Posvetovanja se je ude- ležilo 88 geologov strokovnjakov in študentov, med katerimi je velika večina izsledke svojih raziskav v obliki krajših predavanj predstavila v 8. sekcijah in poster sekciji. Po uvodnih nagovorih je bilo ne- kaj uvodnih minut namenjenih tudi predstavitvi aktivnosti društvenega glasila Prelom. Skrbnik za glasilo je prisotne pozval k oddaji prispevkov. Spletna stran posveta (sl. 1): https://sites.google. com/geo.ntf.uni-lj.si/26-posvet-slovenskih-geolo- gov Na Posvetovanju so vsi udeleženci ob registra- ciji prejeli brezplačen izvod društvenega glasila Prelom, št. 28 (sl. 2). Sl. 1. Vstopna stran na 26. posvetovanje slovenskih geologov. Sl. 2. Društveno glasilo - Prelom št. 28. 172 Glasilo je poželo veliko pohval, predvsem za ponovno obuditev izdajanja. Vseeno bi si želeli, da bi članke prispevalo večje število raznolikih av- torjev. Drugi izziv predstavljata tiskanje in posta- vitev glasila, kar je postalo v tem času precejšen finančni zalogaj. S plačilom članarine aktivni čla- ni podprejo tako delovanje društva, kot tudi obstoj glasila. Zato je društvo sprejelo odločitev, da bo od naslednje številke glasila dalje, Prelom fizično distribuiralo le aktivnim članom društva. Upamo, da bomo s tem spodbudili tudi k priključitvi tudi tiste, ki še niso včlanjeni, a si Prelom želijo prebi- rati. Posledično, bomo aktualno številko glasila na spletno stran naložili z zakasnitvijo. Glasilu smo na prenovljeni spletni strani namenili samostojen zavihek, kjer si lahko obiskovalci pogledajo pre- tekle izdaje glasila. Po malce slabši odzivnosti v post-kovidnem času, smo v preteklem letu zelo uspešno izvedli 3 strokovna predavanja. Po tehtnem premisleku smo se odločili, da bomo uvedli predavanja v hibridni obliki, saj se jih tako lahko udeleži več ljudi in tudi tisti, ki imajo številne aktivnosti po službi ali so od fizične lokacije predavanja precej oddaljeni. Hibri- dna predavanja so bila dobro sprejeta. Ker nismo želeli, da bi bila predavanja omejena le na eno in- stitucijo, smo uvedli spremembe lokacij predavanj. Dosedaj so se društvena predavanja odvila na Ge- ološkem zavodu Slovenjie (GeoZS) in NTF. Pro- mocija predavanj je potekala preko spletne strani SGD (Aktualne novice, Koledar, Aktualna preda- vanja), kjer so posamezniki imeli možnost prebrati povzetke in kratke življenjepise predavateljev, ter preko e-poštnega seznama Georg. Deljenje novic je potekalo tudi preko institucionalnih portalov in osebnih družabnih omrežjih. Tematike, ki smo jih s predavanji v letu 2023 pokrili so geotermi- ja, geokemija in okoljska geologija ter krasoslovje. Prvo predavanje je bilo izvedeno 1. 6. 2023 na Ge- oZS. Nina Rman, Mateja Macut in Simon Mozetič z GeoZS so predstavili »Geološke in geotermalne zanimivosti Islandije« v okviru projekta INFO- -GEOTHERMAL, ki je bil podpora študijskemu obisku Islandije. Predavanje so podprli s fotograf- skim gradivom in predstavitvijo naravnih in kul- turnih zanimivosti Islandije. Dne 6. 11. 2023 smo na GeoZS gostovali podoktorsko raziskovalko Ines Tomašek iz Univerze Clermont Auvergne v Franci- ji. V predavanju z naslovom »Nevarnost za zdravje ljudi zaradi geogenih onesnaževal v mestnem zu- nanjem zraku: priporočila za multidisciplinarno raziskovanje« je Ines Tomašek podala pregled štu- dij o nevarnostih vulkanskih in puščavskih emisij na zdravje ljudi ter opisala uporabo multidiscipli- narnih pristopov k njihovem raziskovanju. Veliko zanimanja je 14. 12. 2023 na Oddelku za Geologi- jo (UL NTF) poželo predavanje Mitje Prelovška z Inštituta za raziskovanje krasa ZRC SAZU (sl. 3). S predavanjem »Kraški pojavi na trasi 2TDK«, je predstavil raziskave krasa in kraških jam na od- sekih izgradnje drugega železniškega tira med Divačo in Koprom. Vabilo na predavanje smo raz- poslali tudi kolegom geografom in geomorfologom, kateri so se pozitivno odzvali. Sl. 3. Predavanje M. Prelovška na OG NTF. Sl. 4. Vabilo na razstavo »Ge- opestrost pred domačim prag- om«, 10. – 14. maj 2023). 173 Društvo je na kongresu v letu 2022, v sklopu obeležitve prvega Mednarodnega dne geopestrosti otvorilo fotografsko razstavo z naslovom »Geope- strost pred domačim pragom«. Sklenili smo, da razstavo preselimo na številne lokacije, kjer bi do- segla še druge radovedne poglede. Skladno z dogo- vorom, smo jo 9. 5. 2023 na dogodku 49. MINFOS otvorili pod istim imenom (sl. 4). Na dan, ko obeležujemo Mednarodni dan ge- opestrosti (6. 10. 2023), smo razstavo preselili v galerijo Mitnica pri NTF in jo poimenovali »Ge- opestrost – zgodbe nežive narave« (sl. 5). Slednja je bila na voljo za ogled en mesec. Tako je postala prava potujoča “geo-fotografska” razstava. Ena najbolj aktivnih skupin oz. sekcij Sloven- skega geološkega društva ostaja Sekcija za pro- mocijo geološke znanosti. Svoje aktivnosti v letu 2023 so pričeli s sestankom 8. junija, kjer so sprejeli naslednje sklepe: SKLEP 1: Predhodni zapisnik je sprejet. Zapi- san povzetek zapisnika sestanka (sl. 6). SKLEP 2: V septembru 2023 je v planu izved- ba sestanka s predmetno komisijo za Naravoslovje na ZRSŠ. Sestanek organizira Petra Žvab Rožič. Naknadno povabimo sodelujoče. Vsi člani sekcije bodite pozorni na informacije (formalne/nefor- malne), ki krožijo in jih javite Roku, ki je koordi- nator te aktivnosti (sestanek je bil organiziran v oktobru – glej nižje). SKLEP 3: Nina Rman in Petra Žvab Rožič pre- gledata plane in tabelo iz prejšnjih let, ter naprej koordinirata vnovično vzpostavitev redne geolo- ške rubrike v Planinskem vestniku. SKLEP 4: Sekcija je sprejela sklep, da do na- daljnjega ne izvaja javnih dogodkov. Vsi morebitni interesenti, ki bi prevzeli koordinacijo in izvedbo posameznih dogodkov ali celotne aktivnosti, naj se javijo Roku po elektronski pošti (rok.brajko- vic@geo-zs.si). SKLEP 5: Predlog, da se v šolskem letu 2023/24 izvede natečaj za učitelje za naj geološko učno gra- divo ni sprejet. Najprej je potrebna priprava celot- nega gradiva, nato sledi izvedba. SKLEP 6: Lea Dvorščak pripravi spisek tehnič- ne opreme, ki jo potrebuje društvo za vzpostavitev podcasta. Rok in Lea (po želji tudi Nejc M.), prip- ravijo predlog uredniške politike. V septembru na sestanku SGD predstavimo zadevo in ugotovimo ali se društvo strinja z podcastom. Potencialna iz- vedba proti koncu leta 2023 ali v 2024. Sekcija je sodelovala pri izvedbi dogodka 49. MINFOS - dnevi mineralov, fosilov in okolja (13. in 14. 5. 2023) ter na prireditvi Koliščarski dan v Dragi pri Igu (26. 8. 2023) – Geološka delavnica (sl. 7). Sekcija je 6. 10. 2023 izvedla delavnico Dan ge- ologije za 76 učencev Osnovnih šol Litija in Šmar- tno pri Litiji. Delavnica je bila izvedena v sklopu Mednarodnega dneva geopestrosti (sl. 8). Na Zavod za šolstvo Republike Slovenije je sekcija na podlagi sestankov iz 18. 10. 2023 in 7. 11. 2023 oddala predlog popravkov in dopolnitev obstoječih učnih načrtov, ki zajema le učne cilje, pri katerih predlagajo spremembe. Cilji, ki se ne- Sl. 6. Povzetek zapisnika sestanka, 8. 6. 2023. Sl. 5. Vabilo na razstavo » Geopestrost zgodbe nežive narave« v galeriji Mitnica pred NTF, 6.10. – 6. 11. 2023). 174 posredno ali posredno nanašajo na geološke vse- bine in so bili prepoznani kot ustrezni (strokov- no, taksonomsko, pravilno umeščeni), niso pa bili obravnavani. Predlagane spremembe učnih ciljev vsebujejo naslednje popravke in dopolnitve: Učni cilji so ustrezno prerazporejeni med razre- dnimi stopnjami in predmeti. Za posamezne učne cilje z geološko tematiko so predlagani strokovni popravki. Predlog vključitve novih učnih ciljev za geolo- ške vsebine, ki v obstoječem sistemu niso zastopa- ne (npr. geološko pogojene nevarnosti). Predlog razširitev ciljev z do sedaj pomanjkljivo predstavljenimi vsebinami (npr. o mineralih, tek- toniki, dinamiki podzemne vode, fosilih in evolu- ciji) ter spremembo poučevanja o mineralnih suro- vinah zaradi zastarelosti ciljev v obstoječih učnih načrtih (Valand, Brajkovič in Torreggiani, 2021). V posameznih primerih so predlagali krčenje geoloških vsebin v učnih načrtih (npr. vsebine o vulkanih, podvajanje vsebin na osnovni takso- nomski stopnji). Na konferenci Museoeurope 2023 je sekcija predstavila interpretacijo geoloških stebrov. Sle- dnji so predstavljeni tudi na spletni strani društva (»Gradiva«). Referenca: KOČEVAR, Tanja Nuša, GABRIJELČIČ TOMC, Helena, ISKRA, Andrej, NOVAK, Matevž, ŽVAB ROŽIČ, Petra. Presentati- on of earth history through digital storytelling and interactive geological columns. V: KOPRIVNIK, Vesna (ur.), SALECL, Dunja (ur.). Srečanja tisočle- tij = The convergence of millennia: Museoeurope: the collected volume of the symposium 19.-21. 10. 2023: [Zbornik mednarodnega simpozija 19.–21. 10. 2023]. Maribor: Pokrajinski muzej = Regional Museum, 2023. Str. 155–166, ilustr. Zbirka Mu- seoeurope, 8. https://museum-mb.si/wp-content/ uploads/2023/10/MuseoEurope_2023.pdf. Člani sekcije za geokemijo so v 2023 nadalje- vali z delom začrtanim že v preteklih letih. Še ved- no je najbolj v ospredju geokemija okolja. Razisku- jejo kemične procese, vsebnosti in porazdelitve na zemeljskem površju, torej v našem okolju. V letu 2023 so bili v Sloveniji izjemni vremenski dogodki, ki so spodbudili raziskave v zvezi s premeščanjem s kovinami obremenjenih materialov. Raziskujejo tudi barja, ki so zelo zanimiva in specifična okolja. Sekcija za geološko dediščino je svoje ak- tivnosti izvajala v sodelovanju z Zavodom Repu- blike Slovenije za varstvo narave. Osrednji dogo- dek Mednarodnega dne geopestrosti je potekal 6. oktobra 2023 v Litiji, kjer je bila okrogla miza z naslovom »Raba mineralnih surovin in njihov po- men za geopestrost« (sl. 9). Strokovnjaki različnih področij so spregovorili o mineralnih surovinah v Sloveniji in njihovi umeščenosti v konceptu geope- strosti. Dogodek je bil tudi medijsko pokrit. Društvo je v letu 2023 organizacijsko in finanč- no sodelovalo z Društvom študentov geologije (DŠG), ki organizira številne strokovne in zabavne vsebine za študente. Med drugim, je bil med 7. in Sl. 7. Geološka delavnica, Koliščarski dan, 26. 8. 2023. Sl. 8. Izvajalci delavnice ob Dnevu geologije pred rudnikom Sitar- jevec. Sl. 9. Okrogla miza v Litiji, ob osrednjem dogodku Mednarodnega dne geopestrosti 2023. 175 13. avgustom organiziran 26. Mednarodni geolo- ški tabor EUGEN (European Geoscience Student Network), ki se ga je udeležilo več kot 90 udeležen- cev. Lokacija tabora je bila zaradi poplav iz Ljub- nega ob Savinji prestavljena v Zavrh pri Borovnici. Člani SGD smo aktivno sodelovali tudi kot stro- kovni vodje ekskurzij. Odzvali smo se tudi pozivu za darovanje znanstvene in strokovne literature za študentski srečelov in študentom podaril več- jo količino knjig in publikacij, ter skrbeli za redno obveščenost študentov o dogodkih, ki se odvijajo v okviru SGD. Društvo je prisluhnilo ideji o ustano- vitvi geološkega podcasta in pomagalo pri pripravi elaborata za potencialno izvedbo. SGD je član EFG – Evropskega združenja ge- ologov. Član društva Marko Komac ostaja pred- sednik EFG, 24 članov društva pa sodeluje v nje- govih strokovnih svetovalnih telesih. Društvo je bilo v letu 2023 vključeno v 3 Evropske projekte Obzorje 2020 (Horizon 2020). V sklopu že zaključenega projekta ENGIE – Vzpodbujanje deklet za izbiro poklica geoznan- stvenice (Empowering Girls to become the geos- cientists of tomorrow), je SGD financiral izdajo prevoda knjižice. Projekt ROBOMINERS – Razvoj bio-navdih- njenega robotskega rudarja (Resilient Bio-Inspired Modular Robotic Miner): v letu 2023 je bilo nare- jenih več prevodov obvestil za javnost (PR4, PR5, PR6, PR7, prevoda Novic Brief Policy), vsi prevodi so dostopni na spletni strani SGD (https://www. slovenskogeoloskodrustvo.si/index.php/medna- rodno-sodelovanje/sodelovanje-v-mednarodnih- -projektih). Poleg tega so bile na spletno stran dodane vse povezave na video gradiva projekta, brošure, opisana je bila tudi predstavitev robota RM-1 v Mežici 25. 10. 2023 idr. Novembra 2023 so se s tem zaključile diseminacijske aktivnosti projekta – obveščanje slovenske javnosti o poteku projekta, prevodi obvestil za javnost in posredova- nje vseh obvestil, za katere je bilo preko Evropske zveze geologov (EFG) zadolženo Slovensko geolo- ško društvo. Projekt REFLECT – Redefiniranje lastnosti geotermalnih tekočin v ekstremnih pogojih (Re- difining geothermal f luid properties at exreme conditions to optimiza future geothermal energy extraction) se izvaja od maja 2020 in je bil po- daljšan do junija 2023. Cilj projekta je prepreči- ti težave povezane s kemijo geotermalnih tekočin še preden nastanejo, tako v geosferi, vrtini in se- stavnimi deli sistemov rabe toplote (izmenjevalci in elektrarne). Projekt REFLECT se je v letu 2023 zaključil. Javnost je bila obveščena o njegovih re- zultatih, s katerimi je bila osvežena spletna stran: https://geo-zs.si(?option=com_content&view=ar- ticle&id=844. Projekt CRM-GEOTHERMAL – Surovine iz geotermalnih f luidov (Critical materials from ge- othermal f luids) se izvaja od julija 2022 in bo pote- kal do maja 2027. Projekt CRM-GEOTHERMAL se ukvarja z razvojem inovativne tehnološke rešitve, ki združuje pridobivanje kritičnih surovin in ener- gije iz geotermalnih tekočin. Ta bo pomagala Evro- pi izpolniti strateške cilje Zelenega dogovora EU in Agende za trajnostni razvoj, hkrati pa zmanjša- la odvisnost od uvoženih CRM-jev. Kombinirano pridobivanje toplote in mineralov iz geotermalnih rezervoarjev ponuja vrsto prednosti: maksimira- nje donosnosti naložbe, minimaliziranje vpliva na okolje, izogibanje dodatni rabi zemljišč, ne pušča rudarske dediščine, dosega skoraj ničelni ogljični odtis in omogoča domačo dobavo kritičnih suro- vin. Naša naloga bo predvsem zagotoviti podatke o potencialu geotermalnih tekočin v Sloveniji. Pro- jekt CRM-GEOTHERMAL je nadaljeval z delom. Diseminacija rezultatov je vidna na projektni sple- tni strani. Njegova predstavitev je bila opravljena na letnem srečanju SZGG v Ljubljani. Projekt CEEGS – Nov sistem geološkega skla- diščenja CO2 s pridobivanjem elektrotermalne energije (CO2 Based Electrothermal Energy and Geological Storage System). Projekt se izvaja od novembra 2022 in bo trajal do oktobra 2025. Pro- jekt CEEGS je 3-letni projekt, ki ga financira Ho- rizon Europe in temelji na razvoju medsektorske tehnologije za energetski prehod. Združuje sistem za shranjevanje obnovljive energije, ki temelji na trans-kritičnem ciklu CO2, geološkem skladi- ščenju CO2 in pridobivanju geotermalne toplote. Glavni cilj projekta je zagotoviti znanstveni dokaz o tehnično-ekonomski izvedljivosti tehnologije in zvišati trenutno nizko raven tehnološke razvitosti (TRL) z 2 na 4 z obravnavanjem vrzeli med po- vršinskim trans-kritičnim ciklom in podzemnim skladiščenjem CO2. SGD je k projektu pristopilo maja 2023, zato se pred tem niso izvajale nobene aktivnosti. Naloga SGD v projektu je diseminacija rezultatov projekta, s čimer v letu 2023 še nismo pričeli, saj večjih rezultatov še ni bilo. V okviru društva deluje tudi zelo aktivna stro- kovna skupina Slovenski nacionalni odbor INQUA (SINQUA), ki povezuje raziskovalce kvar- tarja in skrbi za pretok informacij med slovensko in mednarodno kvartarno znanstveno sfero. Glav- ni cilj skupine je napredek na področju kvartar- nih znanosti, pri čemer si prizadeva za interdisci- plinarno zastopanost članov in večje medsebojno sodelovanje. Vpeti so v aktivnosti INQUA komi- sij in fokusnih skupin, sodelujejo pri organizaciji 176 znanstvenih srečanj in delavnic. V letu 2023 so sodelovali v aktivnostih INQUA komisij in foku- snih skupin. Predstavnik SINQUA je sodeloval na sestankih, volitvah in pri odločanju mednarodne- ga Sveta INQUA. Kot člani INQUA so nadaljevali sodelovanje pri oblikovanju skupnih aktivnosti v okviru različnih komisij. Člani SINQUA smo vpeti v aktivnosti komisij CMP (Coastal and Marine Pro- cesses), PALCOM (Paleoclimates), SACCOM (Stra- tigraphy and Chronology) in TERPRO (Terrestrial Processes, Deposits and History). Aprila 2023 so izvedli 2. SINQUA srečanje, ki je bilo namenjeno predvsem pogovoru o organizaciji SINQUA, priha- jajočih kongresih in predstavitvi dela članov. So- delovali so pri organizaciji in se udeležili kongresa »XXI Congress of the International union for Qu- aternary Research ”Time for Change”«, ki se je od- vijal julija 2023 v Rimu (sl. 10). Kongres je združil znanstvenike iz različnih strok pri preučevanju tem, kot so podnebne spremembe, nihanje morske gladine, poledenitve, rečna dinamika, potresna aktivnost in drugo. Člana SINQUA Miloš Bavec in Petra Jamšek Rupnik sta bila vpeta v »Scientific Advisory Committee«. Bili so so-sklicatelji sekcij: »Millennial paleo-landscape reconstructions of coastal areas - From field data to modelling appro- aches« (Ana Novak), »Quaternary Mediterranean Glaciers« (Manja Žebre) in »Discussion panel on assessing fault capability in different geodynamic and environmantal settings« (Petra Jamšek Ru- pnik). Več članov je prijavilo INQUA kongresni eks- kurziji: »Life with geohazard at the contact of the Alps, the Dinarides and the Pannonian Basin« in »Quaternary archives in the Northeastern Adriatic karst environments«. Ekskurziji žal nista bili izve- deni zaradi nizkega števila prijav. Člani SINQUA so na INQUA kongresu predstavili več predavanj in posterjev o svojem delu in se udeležili več de- lovnih sestankov. Na sestankih znanstvenega svetovalnega odbora INQUA je kot član sodeloval predstavnik SINQUA Miloš Bavec. Petra Jamšek Rupnik je bila med nominiranimi za medaljo sira Nicholasa Shackletona za izjemne mlade kvartar- ne znanstvenike. V okviru CMP komisije so v letu 2023 v okviru projekta NEPTUNE organizirali že omenjeno sekcijo na INQUA srečanju v Rimu (sl. 10). Zaradi velikega števila prijavljenih prispevkov, so bili po kongresu povabljeni k pripravi posebne številke revije Quaternary International. V febru- arju bo zaključen rok za oddajo člankov in lahko pričakujemo, da bo posebna številka izšla v zadnji četrtini leta 2024. Del projektne ekipe NEPTUNE je v 2023 sodeloval pri uspešni prijavi novega CMP INQUA projekta OnSea, ki bo z aktivnostmi začel februarja 2024 in predstavlja nadaljevanje in nad- gradnjo projekta NEPTUNE. Člani SINQUA so pripravili posebno številko revije »Quaternary« z naslovom »Seas, Lakes and Rivers in the Adriatic, Alpine, Dinaric and Pannonian Regions during the Quaternary: Selected Papers from “6th RMQG”«, ki je sledila mednarodnemu znanstvenemu sreča- nju v organizaciji SINQUA s partnerji v letu 2021 in je bila zaključena v letu 2023. Sl. 10. Skupina SINQUA na kongresu v Rimu. Društvo je že peto leto zapored član Medna- rodnega združenja ProGEO, predstavnica Slo- venije je Martina Stupar. Najpomembnejša med- narodna aktivnost v letu 2023 je bil 11. simpozij ProGEO, ki je potekal v mesecu oktobru v Veliki Britaniji v »Charnwood Forest Geopark«. Med- narodno združenje ProGEO organizira simpoziji vsaki dve leti, namenjeni so predstavitvi bazičnih raziskav, varstvu in ohranjanju dediščine, geotu- rizmu, izobraževanju, interdisciplinarnim poveza- vam in drugim aspektom, ki so ključni dejavniki geološke dediščine. Sodelovali smo v soavtorstvu članka »State of the art in geoconservation and geosite inventory in ProGEO Southeast European Regional Group countries (WG1)«, katerega nosil- ka je Georgia Fermely iz ProGEO Grčije. Prispe- vek je bil rezultat sodelovanj v projektu Unesco 737 SMART GEOLOGY, ki se je že zaključil. Za namen priprave analize stanja po posameznih državah Jugovzhodne Evrope smo člani delovne skupine sodelovali z anketo o različnih vidikih na temo promocije, proučevanja in varstva geološke dediščine. Na simpoziju smo se med drugim ude- ležili tudi sestanka skupine za Jugovzhodno Evro- po (WG1), na katerem so bili prisotni predstavniki Hrvaške, Bosne in Hercegovine, Madžarske, Grčije in Romunije. ProGEO je pridružena članica IUGS (Mednarodna zveza geoloških znanosti) in članica IUCN (Mednarodna zveza za ohranjanje narave). Smo tudi član Strokovne skupine EFG za geološko 177 dediščino, podeljujemo tudi pri oblikovanju doku- menta »GEOHERITAGE AND GEODIVERSITY IN NATURE CONSERVATION POLICIES«, ki ga koordinira Monica Sousa v okviru EFG. Med 20. in 24. junijem 2023 je bila v okviru Evropske mineraloške zveze (EMU) v Torinu or- ganizirana šola z naslovom »Minerals in wastes«. Mednarodna šola EMU o mineralnih sestavinah odpadkov, njihovi karakterizaciji, predelavi in rav- nanju. Dogodek je bil delno financiran a žal ni bilo odziva pri študentih. V letu 2023 študentom sofi- nancirajo obisk na Goldschmidt konferenci v Lyo- nu v primeru aktivne udeležbe na konferenci. SGD je včlanjeno v Slovensko inženirsko zbornico (SIZ). S tem je izpolnjen pogoj o obve- znem članstvu SGD v SIZ za pridobitev naziva Evro inženir (EUR ING). V letu 2023 (do 31. 12. 2023) je SGD štelo re- kordnih 101 aktivnih članov, kar je bilo 10 čla- nov več kot leto poprej. Do 13. 3. 2024 je za leto 2024 vplačalo članarino 96 članov. Na 26. Posve- tovanju slovenskih geologov, je društvo podelilo naziv častne članice dr. Katici Drobne (sl. 11). Čestitamo! Sl. 11. Slika s podelitve naziva Častna članica SGD Katici Drobne. Nove publikacije - New Publications Decrouez, D., Finger, W., Haldimann, P., Hofstetter, J.-C., Kündig, R., Meyer, C., Mumenthaler, T., Sieber, N., Spescha, R., Testaz, G. et al. (eds.), 2018: Stein und Wein: Entdeckungreisen durch schweizerischen Rebbaugebiete, AS Verlag & Grafik, Zürich: 612 p. Stone and Wine Discovery tours through Swiss vineyards Starting from the initial observation that en- thusiasm for wine is widespread among geologists, the core of Swiss geologists came to the conclusion that they could contribute with their knowledge and personal efforts to resolve the open techni- cal questions about the inf luence of rocks on the quality of wine. The Department of Earth Scienc- es at ETH Zurich, with the Swiss Geotechnical Commission, recently renamed the Expert Group on Earth Resources, which has been active there since 1899, is credited with launching the pro- ject. The company ‚Verein Stein und Wein‘ was set up and Reiner Kündig, Executive Director of the Swiss Geotechnical Commission, became Edi- tor-in-Chief of the planned publication. A ten-member editorial board coordinated the work of a 63-strong team of authors and a team of more than 40 graphic designers, illustrators, tech- nical consultants and translators for a decade. In order to cover the necessary breadth and complex- ity of the subject, geologists were joined by experts in other branches of geosciences, and wine experts and winegrowers were also consulted. The result is a 612-page publication comprising a main book with 15 chapters and 10 regional volumes. Each of these presents a single geological region or land- scape in more detail. The work was published si- multaneously in German and French. I received the German version of this work from Dr Markus Felber, one of the co-authors, and I refer to it only in my assessment. As early as the 12th century, Benedictine and Cistercian monks dissolved the soil in water and tasted the resulting water solution to determine the suitability of a site for planting vines. The site appropriate according to the taste of solution was then referred to as ‚climat‘ (from the ancient Greek ‚klima‘: the slope of the sun). Even in mod- ern times, wine reviewers often write about wines with a ‚mineral‘ taste. With thousands of minerals, this is rather vague. Apparently, it is supposed to be possible to identify and smell rock materials such as gypsum, metamorphic, schist and volcanic tuff. Kamen in vino Odkrivateljska popotovanja skozi švicarske vinske pokrajine Ob izhodiščni ugotovitvi, da je navdušenje nad vini med geologi splošno razširjeno, je cvet švi- carskih geologov prišel do sklepa, da lahko s svo- jim znanjem in osebnim prizadevanjem prispeva k razrešitvi odprtih strokovnih vprašanj o vplivu kamnin na kakovost vina. Oddelku za znanosti o Zemlji ETH Zürich s tam od leta 1899 delujočo Švicarsko geotehnično komisijo, pred kratkim preimenovano v Strokovno skupino za zemeljske vire, gre zasluga za začetek projekta. Ustanovili so družbo ‚Verein Stein und Wein‘, izvršni direk- tor Švicarske geotehnične komisije Reiner Kündig pa je postal glavni urednik načrtovane publika- cije. Desetglavi redakcijski odbor je celo desetletje usklajeval delo 63-glave avtorske skupine in več kot 40-glave skupine grafikov, ilustratorjev, strokovnih svetovalcev in prevajalcev. V njej so se zaradi potrebne širine obravnave in komple- ksnosti tematike geologom pridružili še strokov- njaki drugih vej geoznanosti, kot svetovalci pa še vinogradniki ter vinarji. Rezultat je 612 strani obsegajoča publikacija, ki obsega glavno knjigo s 15 poglavji in 10 regionalnih zvezkov. Od teh vsak podrobneje predstavlja posamezno eno-ge- ološko regijo oziroma pokrajino. Delo je izšlo so- časno v nemški in francoski verziji. V last sem od dr. Markusa Felberja, enega od soavtorjev, do- bil nemško verzijo tega dela, zato se v svoji oceni sklicujem le nanjo. Že v 12. stoletju so benediktinski in cisterci- janski menihi za ugotavljanje primernosti neke lege za sadnjo vinske trte v vodi raztapljali njena tla in okušali nastalo vodno raztopino. Po okusu te raztopine primerni legi so nato sicer rekli ‚cli- mat‘ (po starogrškem ‚klima‘: nagib lege sonca). Tudi v modernem času vinski ocenjevalci vina pogosto pišejo o vinih z ‚mineralnim‘ okusom. Pri tisočih mineralov je to precej nejasno. Očitno naj bi bilo mogoče prepoznati in vonjati kamninske materiale, kot so mavec, metamorfik, skrilavec in vulkanski tuf. Celo izkušeni geologi pa enako GEOLOGIJA 67/1, 178-185 , Ljubljana 2024 179 Even experienced geologists, however, f ind it as difficult as the rest of us to make the connec- tion between such rock concepts and the sensation of tasting wine. On the other hand, the geological conditions in the vineyards undoubtedly have a significant inf luence on the quality of the grapes. After all, sun exposure, the water regime, the mi- croclimate and the composition of the soil are also a ref lection of geological development. In the 20th century, the term ‚terroir‘, derived from the French word ‚terre‘ (soil), was coined to refer to vineyard sites, but it means much more than the native soil. The question remains: what all and to what extent? In 1997, the Swiss maga- zine Vinum published an article entitled ‚Terroir - the last secret‘, which was met with a very di- vergent response. „What geological factors can be traced and guessed in wine?“ is therefore a chal- lenging question. The authors of this work cannot be faulted for tackling an irrelevant topic. težko kot preostali ljudje vzpostavijo povezavo med takšnimi kamninskimi pojmi in občutkom okušanja vina. Po drugi strani pa geološke raz- mere v vinogradih nedvomno pomembno vplivajo na kakovost grozdja. Navsezadnje so tudi izpo- stavljenost soncu, vodni režim, mikroklima in se- stava tal odraz geološkega razvoja. Za vinske lege se je v 20. stoletju uveljavil iz francoske besede ‚terre‘ (tla) izveden izraz ‚terro- ir‘, ki pa pomeni veliko več kot rodna tla. Odprto je pa ostalo vprašanje: kaj vse in v kolikšni meri? Leta 1997 je tako švicarska revija Vinum objavi- la članek ‚Terroir – poslednja skrivnost‘, ki je bil deležen nadvse divergentnih mnenjskih odzivov. »Kateri geološki dejavniki se lahko zasledijo in uganejo v vinu?« je torej zahtevno vprašanje. Av- torjem tega dela ni možno očitati, da so se lotili irelevantne teme. Povsem logično je bilo, da so se najprej spo- padli s samim pojmom »terroir«. Kasneje je 180 It was only logical that they first tackled the very notion of ‘Terroir’. Later, the Office Interna- tional du Vin gave an officially binding definition: „Terroir encompasses the specific characteristics of soil, relief, climate, landscape and biodiversi- ty“ (OIV 2010). Unfortunately, they have forgot- ten about people and later revised it. It now reads: “Viticultural terroir is a site-based concept where- by a common knowledge is acquired (and defined) for a given site of the interactions between the identifiable physical and biological factors and the viticultural techniques used there that give the products of that site their uniqueness”. These are obviously very important definitions in marketing terms. Unfortunately, they have not helped to re- solve the question with which the authors of ‚Stone and Wine‘ were grappling. The chapter on ‚Terroir‘ is therefore followed by fourteen more steps in which the authors attempt to approach the question by means of an oeno-ge- ological approach. The first eight steps correspond to the titles of the chapters that are also relevant to non-Swiss lay readers: Time, Depth, Topogra- phy, Soil, Water, Elements, Climate, Vines, and, Wine. These are followed by five more Swiss-spe- cific chapters: Underground, Loose Underground, Solid Underground, Assemblages, and, Wine Re- gions/Provinces. These chapters are also of broad- er methodological interest to geologists. ‘Time’ tackles the relativity of the perception of time and the circulation of matter. It offers a fascinating temporal comparison of the evolution of geological and palaeontological events from the Big Bang to the present day, and of the evolution of the vine from its first known seeds 80 million years ago and from the first traces of human wine production in the Caucasus, 8,000 years ago, to the present day. It also parallels the annual growth cycle of the vine with the cycling of rock material from volcanism through erosion, sedimentation, diagenesis, subduction, metamorphism, magma- tism and orogenesis. It also establishes geological (stratigraphic) time archives and time archives of vintages. Through the binoculars of time, it also peers into the temporal development of the forma- tions and soils characteristic of the wine-growing part of Switzerland. ‚Depth‘ parallels the deep structure of the earth, the lithostratigraphic column characteristic of Switzerland, the structure of the soil from the surface of the earth to the bedrock, and the devel- opment of the vine root system. The latter often extends into the bedrock. In conclusion, he notes that it is the nature of the bedrock that determines the depth range of the vine roots. Office International du Vin (Meddržavni urad za vino) podal uradno zavezujočo definicijo: »Terroir zajema posebne značilnosti tal, reliefa, podnebja, pokrajine in biotske raznovrstnosti.« (OIV 2010). Žal pa pri tem pozabil na ljudi, zato jo je kasne- je popravil. Zdaj se glasi: »Vinogradniški terroir je koncept, ki temelji na območju, pri čemer se za zadevno območje pridobi (in opredeli) skupno znanje o interakcijah med prepoznavnimi f izikal- nimi in biološkimi dejavniki ter tam uporabljeni- mi vinogradniškimi tehnikami, ki dajejo proizvo- dom s tega območja njihovo edinstvenost.« Gre za marketinško očitno zelo pomembni definiciji. Žal pa nista prispevali k razrešitvi vprašanja, s kate- rim so se spopadali avtorji dela ‚Kamen in vino.‘ Poglavju »Terroir« zato sledi še štirinajst ko- rakov, v katerih se poskušajo avtorji z eno-geo- loškim pristopom približati odgovoru na obrav- navano vprašanje. Prvih osem korakov ustreza naslovom tudi za ne-švicarske laične bralce po- membnih poglavij: Čas, Globina, Topografija, Tla, Voda, Elementi, Klima, Trta, in, Vino. Tem pa sle- di še pet za Švico specif ičnih poglavij: Podlaga, Nevezana podlaga, Trdna podlaga, Sklopi, in Vin- ske regije/pokrajine. Za geologe pa so metodolo- ško širše zanimiva tudi ta poglavja. »Čas« se spopade z relativnostjo zaznavanja časa in kroženja snovi. Ponuja zanimivo časovno primerjavo razvoja geoloških in paleontoloških dogajanj od velikega poka do danes in razvoja vinske trte od njenih prvih znanih semen pred 80 milijoni let in od prvih, 8.000 let starih, sledi člo- veške pridelave vina na Kavkazu do danes. Tudi kroženju kamninskega materiala od vulkanizma preko erozije, sedimentacije, diageneze, subduk- cije, metamorfizma, magmatizma do orogeneze ponuja vzporednico letnega rastnega kroga vin- ske trte. Vzporeja še geološke (stratigrafske) ča- sovne arhive in časovne arhive vinskih letnikov. Skozi časovni daljnogled pa pokuka še v časovni razvoj za vinorodni del Švice značilnih formacij in tal. »Globina« vzporeja globinsko zgradbo Zemlje, za Švico značilni litostratigafski stolpec, zgradbo tal od površja zemlje do kamninske podlage, ter, razvoj trtnega koreninskega sistema. Slednji po- gosto seže še v kamninsko podlago tal. Za sklep ugotavlja, da prav značilnost kamninske podlage določa globinski domet korenin vinske trte. »Topografija« je specif ično švicarska. Za tiste, ki smo hodili v šole še preden so na njih predavali o tektoniki plošč, pa je hkrati splošno zanimiva. Podaja na tektoniki plošč utemeljen razvoj švicar- skega ozemlja, Alp, Molase in Jure. Z na tektonsko karto Švice vrisanimi vinorodnimi legami se 181 ‘Topography’ is specifically Swiss. Yet, for those of us who went to school before they taught plate tectonics, it is also of general interest. It trac- es the evolution of the Swiss territory, the Alps, Molasses and Jura, based on plate tectonics. It then asks whether vines have tectonic preferenc- es, and consequently preferences linked to erosion and glacial and f luvial accumulation, by means of Swiss vineyard sites drawn on a tectonic map of Switzerland. All this has shaped and defined the current topography of Switzerland. Of course, it cannot avoid considering the effects of solar radia- tion and winds, especially the Fön. After an introductory general explanation of soil pedogenesis, ‘Soils’ focuses on the Swiss soil types. More specifically, the soil types typical of Swiss vineyard sites. Of general interest, however, are the discussion of soil minerals and, of great interest for the soil ‘s ability to retain moisture and for its ability to grow plants, the chapter on ‚Clay - the ‚Protoplasm‘ of the soil ‘. Agronomists and soil scientists are well aware of the role of clay miner- als, but not all geologists. ‘Water’ gives first a general picture of the sur- face and underground water cycle, and then its features of relevance to Switzerland. It also looks at mineral waters as carriers of dissolved salts. However, it is worth highlighting the book‘s ob- jective-oriented chapter on ‚What does water do in the vineyard? The water cycle in the unsaturated and saturated zones of some characteristic geolog- ical and soil substrates is explained in a lucid man- ner. For a selected soil example, the depth evolu- tion of the soil water status and the corresponding densities and thicknesses of the vine root system are given, which is rarely illustrated. The illustra- tion allows the relationships to be understood and the situation to be extrapolated to other soil types. ‘Elements’ focuses on the chemical composition of bedrock, growing soils and wine. The starting point is an interesting comparison of the elemen- tal composition of the Earth from the core to the surface crust, paralleled by the elemental compo- sition of wine (major elements, trace elements and ultra- or micro-trace elements). The vines are seen to store potassium, phosphorus, sulphur, chlorine and carbon, which are rare in the Earth, in the grape berries. Silicon, iron and aluminium, which are very abundant in the Earth, are stored only in traces. The table, which gives an overview of the elemental composition and rock-forming min- erals of the different types of bedrock, takes into account the types of bedrock present in Switzer- land only. However, it is a good basis for an inter- esting illustration of the elements essential to the nato sprašuje, ali ima vinska trta tektonske, po- sledično pa še z erozijo in z ledeniško ter rečno akumulacijo povezane preference. Vse to je na- mreč oblikovalo in opredelilo sedanjo topografijo Švice. Seveda se ob tem ne more izogniti obrav- navi vplivov osončenja in vetrov, še posebej föna. »Tla« se po uvodni splošni razlagi pedogeneze tal posvečajo predstavitvi švicarskih talnih tipov. Bolj specif ično še za švicarske vinogradniške lege tipičnih talnih tipov. Splošno zanimivi pa so raz- prava o mineralih v tleh in za sposobnost tal za zadrževanje vlage in za njihovo rastno sposobnost zelo zanimivo poglavje »Glina – ‚Protoplazma‘ tal«. Agronomi in pedologi se te vloge glinastih mineralov dobro zavedajo, geologi pa ne čisto vsi. »Voda« poda najprej splošno sliko površinske- ga in podzemnega kroženja vode, nato pa njegove za Švico pomembne značilnosti. Posveti se tudi mineralnim vodam kot nosilcem raztopljenih soli. Izpostaviti pa velja k ciljem knjige usmerje- no poglavje »Kaj dela voda v vinogradu?« V njem je na poljuden način sijajno pojasnjeno kroženje vode v nezasičeni in zasičeni coni nekaj značil- nih geoloških in talnih podlag. Za izbrani talni primer je podan sicer redko prikazani globinski razvoj stanja talnih vodnih zalog in temu prila- gojene gostote in debeline trtnega koreninskega sistema. Prikaz omogoča razumevanje odnosov in ekstrapolacijo razmer na druge talne tipe. »Elementi« se posvečajo kemijski sestavi ka- mninske podlage, rastnih tal in vina. Izhodišče je zanimiva primerjava elementne sestave Zemlje od jedra do površinske skorje, vzporejena z ele- mentno sestavo vina (glavni elementi, sledni ele- menti in ultra- oziroma mikro-sledni elementi). Vidi se, da trta v grozdne jagode skladišči v tleh redke kalij, fosfor, žveplo, klor in ogljik. V tleh zelo zastopane silicij, železo in aluminij pa skla- dišči le v sledeh. Tabela, ki podaja vpogled v ele- mentno sestavo in kamninotvorne minerale posa- meznih tipov kamninske podlage upošteva sicer le v Švici prisotne vrste kamninske podlage. Je pa dobra osnova za zanimiv prikaz, katere za vinsko trto bistvene elemente ji ponuja posamezni talni tip in kakšne so s tem v zvezi njene elementar- ne potrebe. Vinska trta je sicer skromna rastlina, a brez dveh snovi ne more: vode in ogljika. Prvo zagotavljajo padavine in ustrezna struktura tal, drugo pa v tleh prisotne organske substance. Z vidika kroženja snovi in f iziologije vinske trte je izjemen slikovni in tekstovni prikaz z naslovom »Elementno- in prehranjevalno- gospodinjstvo vinske trte«. V njem so z vidika izmenjave sno- vi prikazani vsi ključni procesi: fotosinteza nad tlemi (CO2, O2, H2O), v tleh pa sodif ikacija (Na, 182 vine and its elemental needs. The vine is a modest plant, but it cannot do without two substances: water and carbon, the former provided by rainfall and the appropriate soil structure, the latter by the organic substances present in the soil. From the point of view of the cycling of substances and the physiology of the vine, the pictorial and textual presentation entitled ‚The elemental and nutrition- al household of the vine‘ is remarkable. It shows all the key processes from the perspective of material exchange: photosynthesis above ground (CO2, O2, H2O), sodification in soil (Na, Cl), bacterial me- tabolism (NH3, NO2) and the physiological role of roots and water related to mineral weathering and element uptake. Finally, it is worth noting also the interesting picture of the distribution of chemical substances from the deeper core of the grape berry and the pips to its surface skin and stalk. It shows that polyphenols (colouring agents, tannins) are only found in the skin, pips and stalk. This is why, after pressing, red wine can be coloured mainly only in contact with the grape skins. Temperature f luctuations are then shown in more detail for the period of human evolution from the beginning of the Middle Stone Age to the Ro- man Optimum (labelled the ‚Vine Age‘), and on a modified time scale from then to the present. The medieval temperature optimum and the Little Ice Age of the last thousand years are clearly visible. Finally, for the last 160 years, the f luctuation of directly measured air temperatures is shown for Geneva. It shows the temperature maximum in 1944, the cooling between 1944 and 1973 and the subsequent rise. The latter now exceeds the temperatures measured in 1944 by a good degree Celsius. The effects of climate change on vine- yard sites and vines and the resulting necessary changes in Swiss viticulture are presented. This debate is certainly of interest to a wider audience, as wine-growers in Slovenia are also facing similar problems and resorting to similar considerations. ‘The Vine’ gives the history of the human culti- vation and spread of the ’European’ grapevine and its spread to continental Europe in the Roman Em- pire. It cannot, of course, pass over the catastrophe caused in the second half of the 19th century by the introduction of ‚American‘ vines from Amer- ica, which brought the vine louse and, even ear- lier, the fungal diseases peronospora and oidium. European and Swiss viticulture recovered in the 20th century, however, thanks to the grafting of European vines onto American rootstocks. But it is no longer possible to raise and plant grafts and spray the vines without protective agents. Most of this chapter is therefore devoted to a description Cl), bakterijski metabolizem (NH3, NO2) in s pre- perevanjem mineralov in prevzemom elementov povezana f iziološka vloga korenin in vode. Navse- zadnje velja omeniti tudi zanimivo sliko porazde- litve kemijskih snovi od globljega jedra grozdne jagode in pešk do njene površinske kožice in peclja. Kaže, da so polifenoli (barvila, tanini) le v jagodni kožici, peškah in peclju. Prav zato se lahko rdeče vino po stiskanju obarva večinoma le v stiku z grozdnimi kožicami. »Podnebje« ob spremenljivem časovnem meri- lu najprej prikaže nihanje temperature ozračja od začetka kambrija do danes. Nihanje temperature je nato prikazano podrobneje za obdobje človeko- vega razvoja od začetka srednje kamene dobe do rimskega optimuma (označenega kot ‚vinski čas‘), ter v spremenjenem časovnem merilu od tedaj do danes. Lepo sta vidna srednjeveški temperatur- ni optimum in mala ledena doba v zadnjih tisoč letih. In končno je za zadnjih 160 let za Ženevo prikazano še nihanje neposredno merjenih tem- peratur zraka. Kaže temperaturni maksimum v letu 1944, ohladitev med leti 1944 in 1973 in ka- snejši dvig. Ta zdaj že za dobro stopinjo presega v letu 1944 izmerjene temperature. Podani so iz klimatskih sprememb izhajajoči vplivi na vino- gradniške lege in trto in iz njih izhajajoče potreb- ne spremembe v švicarskem vinogradništvu. Ta razprava je gotovo zanimiva tudi širše, saj se tudi v Sloveniji vinogradniki spopadajo s podobnimi problemi in zatekajo k podobnim razmišljanjem. »Trta« podaja zgodovino človekovega gojenja in razširjanja »evropske« vinske trte in njeno razširjenje v kontinentalno Evropo v rimskem ce- sarstvu. Seveda ne more mimo katastrofe, ki jo je v drugi polovici 19. stoletja povzročila z vnosom »ameriške« vinske trte iz Amerike prenešena tr- tna uš, še prej pa od tam izhajajoči glivični bolezni peronospora in oidij. Sledil je popoln zlom evrop- skega vinogradništva in vinarstva. Evropsko in švicarsko vinogradništvo sta si v 20. stoletju s po- močjo cepljenja evropske trte na ameriške podlage sicer opomogla. A brez vzgoje in sadnje cepičev ter škropljenja vinske trte z zaščitnimi sredstvi več ne gre. Večina tega poglavja se zato posveča opisu za švicarske talne in klimatske razmere potrebnih podlag, prikazu današnje sortne sestave njihovih vinogradniških regij, ter, novih sort, ki naj bi švi- carskemu vinogradništvu pomagale ekonomsko preživeti v prihodnje. Za slovenske geologe in vino- gradnike pa je zanimivo poglavje z naslovom »Ko vinograd plazi.« Opisan je zdrs v Opalinski glini, kjer je zdrselo 8.000 m2 terena oziroma 70.000 m3 materiala. Sam sem v mladih letih videl v vinogra- dih v Sloveniji kar nekaj plazov, ki so sicer precej 183 of the rootstocks needed for the Swiss soil and climate conditions, an illustration of the pres- ent-day varietal composition of their wine-grow- ing regions, and the new varieties that should help Swiss viticulture to survive economically in the future. Of interest to Slovenian geologists and vit- iculturists is the chapter entitled „When the vine- yard creeps“. It describes a slip in the Opalin clay, where 8 000 m2 of terrain or 70 000 m3 of materi- al slipped. I myself saw a number of landslides in vineyards in Slovenia when I was young, and al- though they were much smaller in size, they were no less horrific for the affected growers. ‘Wine’ pursues the goal of tasting the ‚stone‘ in the wine: it therefore devotes itself f irst to train- ing our tasting skills. It is common knowledge from our culture that the human palate includes the senses of sweet, sour, bitter and salty. From Japanese culture, there is a fifth taste, ‚umami‘, which is sensitive to glutamic acids and their salts. Its senses have since been medically proven in humans. It is therefore necessary to accept that we have senses for five tastes, two of which are not very well activated in the perception of wine under normal conditions. ‘Wine’ therefore intro- duces the method of the wine sensory expert Hans Blattig, who takes into account the three senses of taste (sweet, sour, bitter) and smell when tasting wine. Blattig thus identifies primarily four build- ing blocks in wine: 1) the soft complex (sweetness, alcohol, glycerine); 2) the acid structure; 3) the tannins or tannic structure; and, 4) the aromatic blanket. He then graphically identifies their occur- rence and duration on the time course of a single wine tasting: 1) 0-2 seconds: initial tasting, 2) 0–4 seconds: two-thirds tasting, 3) 0-6 seconds: three-phase tasting, and 4) 6-12 seconds: after- tasting or finish; after 6 seconds, the wine sample to be tested must be either swallowed or spat out. The soft complex is tasted immediately, the acid structure is delayed and full within 4 seconds, and the tannins are delayed and full within 6 seconds or even later, extending with the acids into the af- tertaste. The aromas are special in that they devel- op immediately but, due to man‘s unusual physi- ological capacity for retro-nasal olfaction, extend far into the aftertaste. All the results of the tast- ings can therefore be presented in terms of taste in a sweet-sour-bitter or sweet-sour-tannin triangle. And this is where the undeniable creativity and innovation of the authors of this work begins: they draw the SAND/silicate - CLAY/silicate - LIME/ carbonate ‚rock triangle‘ from the ETH scripts (ETH 1988). Taking into account the relative pro- portions of carbonate, quartz and clay, practical- zaostajali po velikosti, za prizadete vinogradnike pa niso bili nič manj grozljivi. »Vino« sledi cilju okušanja ‚kamna‘ v vinu: zato se najprej posveti šolanju naših degustacij- skih sposobnosti. Splošno je iz naše kulture zna- no, da obsega človeški okus čutila za sladko, kislo, grenko in slano. Iz japonske kulture je znan še peti, na glutaminske kisline in njihove soli obču- tljiv, okus ‚umami‘. Njegova čutila so bila medtem pri človeku medicinsko dokazana. Treba je torej sprejeti dejstvo, da imamo čute za pet okusov iz- med katerih pa se dva pri zaznavanju vina v nor- malnih razmerah ne aktivirata kaj prida. »Vino« zato predstavi metodo vinskega senzorika Hansa Blattiga, ki pri poskušanju vina upošteva tri vrste čutil za okus (sladko, kislo, grenko) in čutilo vo- nja. Blattig tako v vinu določa prvenstveno štiri gradnike: 1) mehki kompleks (sladkoba, alkohol, glicerin); 2) Kislinska struktura; 3) Tanini oziro- ma taninska struktura; in, 4) Aromatična odeja. Nato pa na časovnem poteku posamične degusta- cije vina grafično opredeli njihovo pojavnost in trajanje: 1) 0-2 sekundi: začetno okušanje, 2) 0-4 sekunde: dvetretjinsko okušanje, 3) 0-6 sekund: trifazno okušanje, in 4) 6-12 sekund: pookušanje; pri čemer je treba po 6 sekundah preskušani vzo- rec vina bodisi pogoltniti, bodisi izpljuniti. Oku- šanje mehkega kompleksa se pojavi takoj, kislin- ske strukture z zamudo in polno v 4 sekundah, taninov pa z zamudo in polno v 6 sekundah ali še kasneje ter sega skupaj s kislinami še v pookus. Posebnost so arome, ki se razvijejo takoj, a segajo zaradi človekove nenavadne f iziološke zmožnos- ti retro-nazalnega voha še daleč v pookus. Vse rezultate degustacij je torej glede okusa možno predstaviti v trikotniku sladko-kislo-grenko ozi- roma sladkoba-kislina-tanini. In tu se začenja nesporna kreativnost in inova- tivnost avtorjev tega dela: Iz skript ETH potegnejo ‚kamninski trikotnik ‘ PESEK/silikat - GLINA/si- likat - APNO/karbonat (ETH 1988). Vanj je mož- no, ob upoštevanju relativnih deležev karbonata, kremena in glin umestiti praktično vse švicarske kamnine (peščenjaki, graniti, gnajsi, silikatni vulkaniti, laporni peščenjaki, skrilavci, apnenci, laporni apnenci, glinasti apnenci, apneni pešče- njaki, laporni apneni peščenjaki, itd.). Hkrati po- tegnejo iz najnovejše literature ‚trikotnik okusov‘, ki ga je v letu 1995 objavil C. Sitter. V njem je izenačil pesek s kislostjo, apno s polnostjo in gli- no z adstringentnostjo. Sitter v svojem trikotniku okusov opredeli še 39 različnih oznak okusa, pri čemer za območje z najmanj 20 % vsake od treh kamninskih komponent določi notranji trikotnik ‚harmonično uravnoteženih okusov‘. Avtorji dela 184 ly all Swiss rocks (sandstones, granites, gneisses, siliceous volcanics, lacustrine sandstones, shales, limestones, lacustrine limestones, clayey lime- stones, calcareous sandstones, lacustrine calcar- eous sandstones, etc.) can be placed in it. At the same time, they draw on the most recent literature the ‚triangle of f lavours‘ published by C. Sitter in 1995. In it, Sitter equated sand with acidity, lime with fullness and clay with astringency. He de- f ines 39 different f lavour codes in his triangle of f lavours, identifying an inner triangle of ‚harmo- niously balanced f lavours‘ for an area with at least 20 % of each of the three rock components. The au- thors of ‚Stone and Wine‘ f irst rotate Sitter‘s trian- gle of f lavours by 60 °, so that in the rock triangle, sour lies between limestone and sandstone, tannic between limestone and claystone, and sweet be- tween claystone and sandstone. They then main- tain a central area of harmony and reduce the number of too many f lavour notes to just three: strong towards clay, fresh towards sandstone and structured towards limestone. With this appara- tus, they then set about systematically tasting the Swiss wines. The testers are all co-authors of this work and many invited winemakers and experts. In the Blattig method, the intensity of the f lavours is plotted on a timeline of the development of the f lavours on the ordinate axis and the results are rigorously evaluated at the end. Through their testing method, the authors demonstrate that the rock bed has an undeniable inf luence on the characteristics or f lavour of the wine. However, they acknowledge that this inf lu- ence is sometimes quite pronounced and some- times barely perceptible. In his review of the work, Thomas Vaterlaus, Editor-in-Chief of the Swiss wine magazine Vinum, therefore concludes: ‚Stone and Wine‘ brings us closer to the important links, clarifies them for us, which ultimately contributes to making Swiss wines even more enjoyable in the future, because we will all drink ‚with understand- ing‘. But the magic remains.“ ‘’Underground’, based on the links identified in the „Wine“ chapter, present the „Oeno-geological map of Switzerland“, derived from the geotechni- cal map of Switzerland. It covers 8 types of solid rock, 4 types of loose rock, 2 types of assemblages (molasses and f lysch) and all Swiss vineyard sites. The distribution of the underground basement rock types in each of the oeno-geological regions or ar- eas is also shown. The chapter on ‚Underground‘ is followed by chapters on ‚Loose Underground‘, ‚Solid underground‘ and ‘Assemblages’, which give a more detailed picture of the nature and distribu- tion of the different types of bedrock. ‚Kamen in vino‘ najprej zasučejo Sitterjev triko- tnik okusov za 60˚ . Tako, da leži v kamninskem trikotniku kislo med apnencem in peščenjakom, taninično med apnencem in glinovcem, sladko pa med glinovcem in peščenjakom. Nato ohranijo središčno območje harmonije in zmanjšajo števi- lo preštevilnih oznak okusa na vsega tri: močno v smeri glinovca, sveže v meri peščenjaka in struk- turirano v smeri apnenca. S tem aparatom se nato lotijo sistematičnega poskušanja švicarskih vin. Preizkuševalci so vsi soavtorji tega dela ter mnogi povabljeni vinarji in strokovnjaki. Pri Blattigovi metodi nanašajo ob tem na časovni diagram ra- zvoja okusov na ordinato še njihovo intenzivnost in na koncu rigorozno vrednotijo rezultate. S svojo preizkuševalno metodo avtorji dokaže- jo, da ima kamninska podlaga nedvomen vpliv na značilnosti oziroma okus vina. Priznavajo pa, da je ta vpliv včasih povsem izrazit, včasih pa komaj zaznaven. Glavni urednik švicarske vinarske re- vije Vinum Thomas Vaterlaus v svoji oceni dela zato ugotavlja: „Kamen in vino“ nam približa po- membne povezave, nam jih razjasni, kar na koncu prispeva k temu, da nam bodo švicarska vina v prihodnosti nudila še več užitka, saj bomo vsi pili „z razumevanjem“. Toda magija ostaja. »Podlaga« na osnovi v poglavju »Vino« ugoto- vljenih povezav podaja iz geotehnične karte Švice izvedeno »Eno-geološko karto Švice«. Zajema 8 vrst trdnih kamnin, 4 vrste nevezanih kamnin, 2 vrsti sklopov kot bolj ali manj ciklično plastovi- tih formacij (molasa in f liš) in vse švicarske vi- nogradniške lege. Prikazana je tudi porazdelitev kamninskih tipov po posameznih eno-geoloških regijah oziroma območjih. Poglavju »Podlaga sledijo še poglavja »Nevezana podlaga«, »Trdna podlaga« in »Sklopi«, ki še natančneje predsta- vijo značaj in razširjenost posameznih vrst ka- mninske podlage. »Vinske regije« so zaključno inovativno pog- lavje tega dela. Avtorji na osnovi svojih v po- glavjih »Vino« in »Podlaga« prikazanih dognanj opredelijo v Švici obstoj 10 eno-geoloških vinskih regij ter te regije kartografsko prikažejo v zad- njem poglavju. To je precejšnja novost. Zakonsko so v Švici namreč določene le tri vinske regije: a) Regija zahodne Švice, b) Regija nemške Švice, in, c) Regija italijanske Švice. Po politično-kulturnih kriterijih pa ločijo 6 vinskih regij. Geologi so torej zdaj njihovo število na osnovi eno-geoloških kri- terijev povečali na 10. Vinskim regijam se posveča 10 regionalnih zvezkov (zaradi jasnosti ohranjam imena izvir- nika): Jura Nord, Mittelland, Alpenseen, Alpenr- hein, Tessin, Wallis, Chablais, Balcon lémanique, 185 ‘Wine Regions’ is the final innovative chapter of this work. Based on their findings in the chap- ters ‘Wine’ and ‘Underground’, the authors identi- fy 10 oeno-geological wine regions in Switzerland and map these regions in the final chapter. This is a significant innovation. Only three wine regions are legally defined in Switzerland: a) the Western Switzerland Region, b) the German Switzerland Region, and c) the Italian Switzerland Region. The 6 vine regions are separated by political-cultural criteria. Geologists have therefore now increased the number of regions to 10 on the basis of oe- no-geological criteria. The wine regions are the subject of 10 region- al volumes (for the sake of clarity, I am retaining the original names): Jura Nord, Mittelland, Alpen- seen, Alpenrhein, Tessin, Wallis, Chablais, Bal- con lémanique, Genf, and Drei-Seen-Land. They are wonderful geological, viticultural and cultural guides through these regions. Anyone who wants to go through them as a geologist - even if they are not a wine lover - will certainly find them a valuable guide. However, wine lovers may find themselves in trouble by too much tempting infor- mation. What to add in conclusion? What I f ind im- mensely fascinating about the main book is the approach, starting in each chapter with a popular explanation of the most general concepts of sci- ence. Then, through technically and technologi- cally relevant explanations, it gets to the region- al data and characteristics that are important for Swiss viticulture. The book is therefore a very in- teresting encyclopaedic source of general natural science and specific viticultural knowledge, even for non-Swiss readers. As a geologist or hydro- geologist, I am fascinated by both the clarity of the lay scientific presentations and the scientific rigour in the approach to uncovering the links be- tween wines and the bedrock for wine tasting. As someone who was born at the Maribor Vineyard and Wine School as the son of a later university professor of viticulture and winemaking, and who has grown up and lived with vines and wine all his life, I was also touched by the clarity and precision of the presentation of the physiology of the vine and wine tasting. I judge ‚Stone and Wine‘ to be a magnificent monument to Swiss geology, viticulture and wine- making. It can be a model for all those who do not yet have something similar. Dr. Miran Veselič Prof. Emeritus UNG Genf, in, Drei-Seen-Land. Predstavljajo čudovite geološke, vinogradniško-vinarske in kulturološke vodnike skozi te regije. Kdor se želi skoznje poda- ti kot geolog - celo če ni ljubitelj vina – mu bodo gotovo dragocen vodnik. Kdor je ljubitelj vina, se pa utegne znajti v težavah zaradi prevelikega šte- vila vabljivih informacij. Kaj dodati za zaključek? Pri glavni knjigi me neizmerno očara pristop, ki v vsakem poglavju izhaja od poljudno prikazanih najbolj splošnih naravoslovnih pojmov. Nato pa preko tehnično- -tehnološko pomembnih razlag pride do za švi- carsko vinogradništvo pomembnih regionalnih podatkov in značilnosti. Knjiga je zato tudi za ne- -švicarske bralce nadvse zanimiv enciklopedični vir splošnih naravoslovnih in specif ičnih vino- gradniško/vinarskih znanj. Kot geologa oziroma hidrogeologa me fascinirata tako jasnost polju- dno znanstvenih prikazov kot znanstvena rigo- roznost v pristopu k odkrivanju povezav med vini in kamninskimi podlagami namenjenim vinskim degustacijam. Kot nekoga, ki je bil na mariborski vinogradniško-vinarski šoli rojen kot sin kasnej- šemu univerzitetnemu profesorju vinogradništva in vinarstva, in, ki je vse življenje rasel in živel s trto in vinom, pa se me je dotaknila tudi jasnost in natančnost predstavitev f iziologije vinske trte in vinskih degustacij. Sodim, da je delo »Kamen in vino« veličasten spomenik švicarski geologiji, vinogradništvu in vinarstvu. Lahko je vzor vsem tistim, ki česa po- dobnega še nimajo. dr. Miran Veselič zasl. prof. UNG G E O L O G I J A št.: 67/1, 2024 www.geologija-revija.si 7 Žvab Rožič, P. Hydrogeochemical and Isotopic Characterisation of the Učja Aquifer, NW Slovenia 25 Gale, L. & Rožič, B. Signs of crustal extension in Lower Jurassic carbonates from central Slovenia 41 Gosar, M., Bavec, Š., Miler, M. & Gaberšek, M. Vsebnosti potencialno strupenih elementov v sedimentih in vodah reke Meže in njenih pritokov, ki odvodnjavajo odlagališča rudarskih odpadkov 63 Dernov, V. Palaeoecological significance of the trace fossil Circulichnis Vyalov, 1971 from the Carboniferous of the Donets Basin, Ukraine 71 Skaberne, D., Čar, J., Pristavec, M., Rožič, B. &. Gale, L. Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia 105 Kanduč, T. & Markič, M. Isotopic composition of carbon (δ13C) and nitrogen (δ15N) of petrologically different Tertiary lignites and coals 129 Placer, L., Popit, T. & Rižnar, I. Tectonics and gravitational phenomena, part two: The Trnovski gozd-Banjšice-Šentviška Gora degraded plain 157 Mencin Gale, E., Kralj, P., Trajanova, M., Gale, L. & Skaberne, D. Petrology dataset of Pliocene-Pleistocene sediments in northeastern Slovenias ISSN 0016-7789 2024 | št.: 67/1 20 24 | št .: 67 /1