Upper Permian Oil Shale Deposits of Northwest China: World s s Largest?

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1 Upper Permian Oil Shale Deposits of Northwest China: World s s Largest? Alan R. Carroll Department of Geology and Geophysics University of Wisconsin-Madison

2 Largest Oil Shale Deposits Deposit Period Oil In Place (10 6 tons) United States (Green River Fm.) Tertiary 213,000 United States (Phosphoria) Devonian 35,775 United States (Eastern) Devonian 27,000 United States (Heath Fm.) Teriary 25,778 Russia (Olenyok basin) Cambrian 24,000 Republic of Congo? 14,310 Brazil (Irati Fm.) Permian 11,448 (Dyni, J. R., 2006, Geology and Resources of Some World Oil-Shale Deposits: USGS Scientific Investigations Report , 42 p.)

3 China Lake Basins Late Permian Early Cretaceous Early Jurassic Oligocene

4 Late Permian Junggar-Turpan Turpan-Hami Lake (Carroll, and Wartes, 2003) Permian Lake approximately equal in area to modern Caspian Sea

5 Tectonic Setting Junggar-Turpan-Hami basins part of Altaid orogenic collage, lie at center of Asia Substrate has oceanic affinities; trapped or accreted ocean crust Continuous non-marine sedimentation from Permian onward Deformation focused on basin margins Map: Exxon

6 Tectonic Basin Model Compressional uplift of basin-bounding walls Turpan-Hami basin in wedge-top position?

7 Comparison to Green River Fm. Similar or greater in area Greater thickness Silicic vs. carbonate-rich Similar richness?

8 Late Permian Lacustrine Deposits (Carroll, and Wartes, 2003) Distributed in several basins Post-Permian deformation Outcrops in foothills of Bogda Shan (Jurassic and later uplift)

9 Junggar South-North Cross Section Hongyanchi Fm. Lucaogou Fm. Jingjingzigou Fm (Carroll, and Wartes, 2003) Regionally correlative interval up up to m thick

10 Tianchi Section (N. Bogda Shan) Jingjingzigou, Lucaogou Fms. Dominantly silicic mudstone, siltstone Average 4% TOC over 800 m interval Total outcrop thickness 1300 m (Carroll et al., 1992)

11 Underfilled (Jingjingzigou Fm.) m-scale cycles shrinkage cracks dolomicrite

12 (Carroll, 1998)

13 Balanced-fill (Lucaogou, Taerlong Fms.) turbidites oil shale

14 (Carroll, 1998)

15 Overfilled (Hongyanchi Fm.) Silicic mudstone, freshwater limestone

16 (Carroll, 1998)

17 Organic Enrichment (Jingjingzigou, Lucaogou, Honyanchi Fms) Mean = 34.9 mg/g (samples 0.5% TOC) Mean = 4% (all samples) Mean = 5.7% (samples 5% TOC) Max. 34.3% Mean = 64.4 mg/g (samples 5% TOC) Max mg/g Sample Interval ~ 10 m ~1500 m total section (N = 153)

18 Junggar Permian-Sourced Oils Permian oils in northwestern, central, and eastern Junggar basin Southern Junggar basin over-mature due to deep Mz-Cz. burial

19 Conclusions NW China Permian lacustrine deposits cover an area approximately equal to Caspian sea, and locally exceed 2 km in thickness Based on LECO and Rock Eval measurements, maximum richness appears to be comparable to Green River Formation Much of the original oil potential has already been expended by thermal maturation, due to deep post-permian burial Remaining resource likely very large, but detailed mapping and bulk assay data have not been published Structural complexity will influence exploitation These deposits are absent from previous global oil shale assessments, and surprisingly poorly known even within China More work needed!

20 Acknowledgements Collaborators Y. Liang S. A. Graham M. S. Hendrix T. J. Greene M. A. Wartes Funding Stanford-China Industrial Affiliates Donors of the Petroleum Research Fund, American Chemical Society Graduate School, University of Wisconsin

21 For More Information Carroll, A. R., 1998, Upper Permian Lacustrine Organic Facies Evolution, Southern Junggar Basin, NW China: Organic Geochemistry, v. 28, p Carroll, A. R., and Bohacs, K. M., 2001, Lake Type Control on Hydrocarbon Source Potential in Nonmarine Basins: American Association of Petroleum Geologists Bulletin: American Association of Petroleum Geologists Bulletin, v. 85, p Carroll, A. R., and Wartes, M. A., 2003, Organic Carbon Burial by Large Permian Lakes, Northwest China, in Chan, M. A., and Archer, A. W., eds., Extreme depositional environments: mega end members in geologic time: Geological Society of America Special Paper 370, p Carroll, A. R., Brassell, S.C., and Graham, S.A., 1992, Upper Permian lacustrine oil shales of the southern Junggar basin, northwest China: American Association of Petroleum Geologists Bulletin, v. 76, p Carroll, A. R., Graham, S.A., and Hendrix, M.S., 1995, Late Paleozoic tectonic amalgamation of northwestern China: sedimentary record of the northern Tarim, northwestern Turpan, and southern Junggar basins: Geological Society of America Bulletin, v. 107, p Carroll, A. R., Graham, S.A., Hendrix, M.S., Chu, J., McKnight, C.L., Xiao, X., and Liang, Y., 1990, Junggar basin, northwest China: Trapped late Paleozoic Ocean: Tectonophysics, v. 181, p Graham, S.A., Brassell, S., Carroll, A. R., Xiao, X., Demaison, G., McKnight, C.L., Liang, Y., Chu, J., and Hendrix, M.S., 1990, Characteristics of selected petroleum source rocks, Xinjiang Uygur Autonomous Region, China: American Association of Petroleum Geologists Bulletin, v. 74, p Wartes, M. A., Carroll, A. R., and Greene, T. J., 2002, Permian Stratigraphic Evolution of the Turpan-Hami Basin and Adjacent Regions, Northwest China: Constraints on Post-amalgamation Tectonic Evolution: Geological Society of America Bulletin, v. 114, p Wartes, M. A., Carroll, A. R., Greene, T. J., Cheng, K., and Hu, T., 2000, Permian lacustrine deposits of northwest China, in Gierlowski-Kordesch, E. H., and Kelts, K., eds., Lake Basins Through Space and Time: American Association of Petroleum Geologists Studies in Geology #46, p