Carbon isotope (δ13C) characteristics of middle Miocene Çayirhan oil shales (Beypazari, Ankara/Turkey): Implications on paleoenvironment and paleoclimate

Çayırhan oil shales situated 100 km NW of Ankara were formed in the Hırka formation of the middle Miocene age. This formation is a volcanosedimentary sequence and represented by a high content of organic material (TOC 2.08–23.29%, average 9.53%). Paleoecological and paleoclimate conditions during the formation of these shales were outlined by geochemical proxies. Results of the organic geochemical studies determined high Total Organic Carbon...