Spodnje jurske plasti v Preserju pri Borovnici
Lower jurassic beds at Preserje near Borovnica (Central Slovenia)

slovenian

2009

volume 52, issue 2

Geološki zavod Slovenije
(Obvezni izvod spletne publikacije)

Described is a 50 m thick cross-section, which includes 26 cyclothems. Beds ofbiomicritic, in some places oolitic, limestone are interrupted by dolomitized laminites, thinner beds of flat pebble conglomerate, and rarely stromatolites. The bedrock of the cross-section is sparitic dolomite. The contact between Triassic and Jurassic is not included in the cross-section. Lithological varieties indicate sedimentation in the subtidal zone in the protected part of a shallow shelf within the Adriatic Dinaric carbonate platform with occasional connection with the open sea. Dolomite in the laminites and flat pebble conglomerate is of early diagenetic origin. It developed through capillary concentration of pore solutions in intratidal and supratidal environment. The Lower Jurassic age of the limestone is determined by Palaeodasycladus mediterraneous Pia algae. Chemical analyses include Ca, Mg, as well as, Sr, Fe, Mn and Na. Beds containing dolomite of early diagenetic origin are rich with Fe and Na.

01.08.2011