Sedimentation and diagenesis of the Upper Oxfordian cyanobacterial-sponge limestones in Piekary near Kraków

Abstract

Sedymentacja i diageneza sinicowo-gąbkowyh wapieni górnego oksfordu w Piekarach koło Krakowa Components of cyanobacteria! origin and siliceous sponges are the main rock-forming components of the limestones studied. Massive limestone occurs in the rigid- framework cyanobacterial-sponge buildups that formed elevations on the basin floor. Bedded limestone was laid down in extensive depressions between the elevations. Sedimentation took place in a quiet environment where intense water movements occurred only sporadically. There are numerous indications of the shallowness of the sea, which meant that elevated areas of the bottom were episodically emerged. Chert horizons have formed along the surfaces of synsedimentary stratification where the clay content was locally elevated. The bedding of the limestones is of diagenetic origin and is related to the diagenetic redistribution of calcium carbonate during burial.