Physical Sciences and Mathematics Commons^™

Carbon And Oxygen Isotope Ratios In Rona Limestone, Romania, Stela Cuna, Dana Pop, Alexandru Hosu

Studia UBB Geologia

The carbon and oxygen isotopic compositions of limestones provide criteria for the evaluation of the depositional environment. For Jurassic and younger samples, the best discrimination between marine and fresh-water limestones is given by Z parameter, calculated as a linear correlation between δ13C and δ18O (‰ PDB). Rona Limestone (Upper Paleocene - Lower Eocene), outcropping on a small area in NW Transylvania (Meseş area) is a local lacustrine facies. There, it divides Jibou Formation into the Lower Red Member and the Upper Variegated Member, respectively. Recently, a sequence containing a marine nannoplankton assemblage was identified in the base of Rona deposits. …