Investigation of trace element enrichment in organic matter rich rocks in the cenomanian-turonian transition in Western Taurus (Antalya, Turkey)

The Cenomanian-Turonian Boundary Event (CTBE) period has important geological characteristics reflecting the presence of major hydrocarbon source rocks, trace element enrichments observed in organic matter-rich black shales, and Oceanic Anoxic Events (OAE's). According to the trace element distributions determined in 22 samples taken from Çataltepe Nappe, Dereköy Formation CTBE black shale units, which are included in Antalya Nappes located in the Western Taurus, Ag, Mo, Se, Cd, Zn, U and V show higher enrichment compared to other elements. The highest trace element enrichments were determined especially in samples with high total organic carbon (TOC) content. The positive relationship between redox-sensitive trace elements (eg Mo, U, V etc.), total sulfur content (TS) and TOC content detected at high concentrations in TOC-rich samples indicates that the depositional environment may be in anoxic-euxinic conditions. The maximum TOC value obtained from the black shale samples of the Dereköy Formation is 30.56%, and the enrichment factors of MoEF (1,167.51), UEF (152.54), and VEF (67.70) trace elements used in the evaluation of the redox facies and TOC exhibit strong covariation. Keywords: Cenomanian-Turonian Boundary; Black shale; Organic matter; Trace elements; Anoxic conditions; Antalya Nappes; Western Taurides