Source rock characterization and depositional environment of the late Cretaceous Haymana Formation in the Salt Lake Basin of Turkey

Late Campanian-Maestrichtian Haymana Formation of the Salt Lake Basin, Turkey was deposited in a forearch Basin. This formation has been studied by a combination of organic geochemical methods (LECO/Rock-Eval, sulphur, gas chromatography), light microscopy, and bulk combination method (elemental analysis) in order to assess the hydrocarbon source potential of the abundant and extensive shale intervals presents in the formation. The shales have an organic carbon content (TOC) up to 1.69% and hydrogen index (HI) values up to 380. Pyrolysis yields (TOC, S-2, and HI) and organic petrography (kerogen type, amount%) indicate that the shales are dominantly gas potential, containing Type III and II organic matter. Thermal maturity, assessed from Spore Colour Index and T-max, indicates that late Campanian-Maestrichtian Haymana Formation in the Salt Lake Basin range from diagenetic to over mature with respect to oil generation and may produce gas and oil. The values for the V/Cr ratio of shales vary from 0.29 to 3.20, indicating dysoxic and anoxic conditions for bottom water.