AAPG Bulletin, V. 84, No. 8 (August 2000), P. 1109-1128.

Molecular Organic Geochemistry of the Tarim Basin, Northwest China¹

©Copyright 2000. The American Association of Petroleum Geologists. All rights reserved.
¹Manuscript received November 12, 1998; revised manuscript received January 3, 2000; final acceptance February 15, 2000.
²Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305-2115. Present address: Texaco International Exploration, 4800 Fournace Place, Houston, Texas 77401; e-mail: [email protected]
³Research Institute of Petroleum Exploration and Development (RIPED), China National Petroleum Corporation, Beijing, People's Republic of China.
⁴Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305-2115.
Financial support for this study was provided by the Stanford China Industrial Affiliates and the Stanford Molecular Organic Geochemistry Industrial Affiliates Programs. J. M. Moldowan acknowledges partial research support from ACS-PRF Grant 30245-AC2. Aromatic GC-MS data were generated by Mike Darnell at the Geotechnology Research Institute at the Houston Advanced Research Center with expenses paid by Texaco's International Exploration Division. Gordon Wood of Amoco provided Mesozoic outcrop source rock samples from northern Tarim. Technical support was provided by Fred Fago and David Zinniker. Statistical advice was provided by Paul Switzer and Tom Hickson. Discussions with Vaughn Robison, David Zinniker, and Brad Ritts, and critical reviews by Ken Peters, Greg Ulmishek, Roger Sassen, Steve Graham, and Brad Ritts improved this paper. Texaco Exploration paid for color figure reproductions.

ABSTRACT

We conducted organic geochemical analyses on the largest suite of oils and source-rock extracts from the Tarim basin, northwest China, currently available. Statistical cluster analysis of the entire suite of Tarim oils distinguishes at least seven genetic groups of oils. The largest group of oils was collected from the Tazhong and Tabei uplifts and originated from marine Middle-Upper Ordovician anoxic marls that mark slope facies at the margins of structural uplifts. Two other genetic groups most likely originated from marine Middle-Upper Ordovician source rocks, but of distinct facies, with one an oxic shale-rich source west of the Bachu uplift and the other an anoxic shale source at Tazhong.