Ce anomaly at the Permian-Triassic boundary in the Idrijca Valley as evidence of changing redox conditions at the P/Tr transition in the western Tethys (Slovenia)

Abstract

The shape of the Ce/Ce* curve suggests that oceanic anoxia was typical of the Upper Permian during sedimentation of the Žažar Formation, and that the transition to more oxygenated conditions occurred at the P/Tr boundary. An abrupt change of redox conditions at the P/Tr transition in this part of the Western Tethys coincides with the terminal phase of the Upper Permian marine regression, as well as with the drastic disappearance of typically marine fauna of algae, foraminifers and brachiopods.