Petroleum Geology of East Siberia
CLARKE, JAMES W., U.S. Geological Survey, Reston, VA
Two oil-gas provinces are present in East Siberia: the Lena-Tunguska in the central, southern, and western parts, and the Khatanga-Vilyuy along the northern and eastern margins. The provinces developed as rift-sag features in late Proterozoic and Paleozoic time. The identified oil and gas deposits of the Lena-Tunguska province appear to be associated with a Proterozoic rift that extends east-northeast across the southern part of the basin. These deposits are in upper Proterozoic and Cambrian sandstones and carbonate rocks, sealed by Cambrian salt and argillites. The oil and gas deposits of the Khatanga-Vilyuy province are within foreland downwarps that developed in connection with docking of crustal plates during the Mesozoic: during the Triassic on the north and during the Cretaceous on the east. The source of the petroleum in the immature rocks of the southeastern Lena-Tunguska province is uncertain, perhaps being derived from rocks in a downwarp to the south or from source beds that are now beneath a conjectured thrust sheet. This province has both oil and gas pools, but is gas prone in general. The source beds for the Khatanga-Vilyuy province are Permian and Mesozoic in age; the province is gas prone. More than 40 oil and gas fields have now been discovered in East Siberia.
AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)