Source Rock Characteristics and Hydrocarbon Potential of the Late Cretaceous Deposits in the Eastern Black Sea Region, NE Turkey

Abstract

In this article, source rock characteristics and hydrocarbon potential of the late Cretaceous turbidite sequences in the eastern Black Sea region were investigated. The total average organic carbon (TOC) contents of sequences in Trabzon, Gümüshane, Giresun, and Erzurum are 0.06, 0.18, 0.12, and 0.30 wt%, respectively. In addition, low potential yield (PY), low hydrogen index (HI), and very high oxygen index (OI) values were calculated for these sequences. On the basis of T_max values, most of sequences are thermally immature, and only some parts are mature and over-mature. Sequences generally contain residual organic matter and lesser amounts of type III kerogen. CPI values higher than 1, n-alkane distributions with high carbon numbers, and type III kerogen content indicate that organic matter has a terrestrial origin. The Pr/Ph ratios calculated as 1.10 and 2.15 for the Mescitli section of the Gümüshane region and the Tortum section of the Erzurum region reveal that the Mescitli section was deposited in a suboxic environment, while the Tortum section was in an oxic environment. According to these data, late Cretaceous sequences show weak source rock characteristics.

Keywords:

• GC
• late Cretaceous
• maturity
• oil generation
• source rock
• TOC

Acknowlegments

The authors would like to thank the Research Foundation of Karadeniz Technical University (Project No. 98 112.005.6) and the Canadian Geological Society (CGS) Geochemical Lab for the support in field and analyzing the data. The authors also gratefully acknowledge Dr. Snowdon (CGS) for his help.