About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin


AAPG Bulletin, V. 94, No. 12 (December 2010), P. 18271857.

Copyright copy2010. The American Association of Petroleum Geologists. All rights reserved.


Hydrocarbon occurrences in the western Anatolian (Aegean) grabens, Turkey: Is there a working petroleum system?

N. Bozkurt Ciftci,1 R. Ozgur Temel,2 Y. Haluk Iztan3

1Turkiye Petrolleri A.O. (TPAO), Exploration Group, TR-06100 Ankara, Turkey; present address: Commonwealth Scientific and Industrial Research Organisation (CSIRO) Earth Science and Resource Engineering, P.O. Box 1130, Bentley, WA 6102, Australia; [email protected]
2Turkiye Petrolleri A.O. (TPAO), Exploration Group, TR-06100 Ankara, Turkey; [email protected]
3Turkiye Petrolleri A.O. (TPAO), Exploration Group, TR-06100 Ankara, Turkey; [email protected]


Western Anatolian graben basins are filled with continental sediments and minor carbonates deposited in lacustrine, alluvial, and fluvial environments. Individual grabens are composite basins and comprise multiple depocenters or subbasins, with sediment thickness rarely exceeding 3000 m (9843 ft). A number of hydrocarbon occurrences are reported from the basins. Regional geologic framework justifies these occurrences by providing a generous heat budget, good quality source rock, fair reservoir seal sequences, and suitable traps, although no economically producible reserves have been discovered to date. The rich source rock with an average total organic carbon of 2.34% and hydrogen index up to 800 mg/g is oil and gas generative at maturation. However, the composite nature of the grabens controlled the stratigraphic variability and led to sporadic distribution of the lacustrine deposits hosting the source rock facies in the basins. The depth of burial is generally insufficient (lt2000 m [6562 ft]) for the source rock to effectively generate and expel hydrocarbons. This limitation was locally overcome by additional heat input into the system through deep-reaching faults, volcanism, and/or after volcanic hydrothermal circulation. Thermal maturity of organic matter effectively increases in the vicinity of the major border structures, volcanic rocks, and zones of polymetallic mineralization, yet this effect is typically constrained within a narrow zone adjacent to heat source and diminishes within short distances. Thus, the hydrocarbon system remains regionally inefficient. Exploration success in the region depends on the discovery of deeper Neogene depocenters that could provide sufficient source rock burial depths.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Member username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].