• journal_title：Geological Society of America Bulletin
• Contributor：Edward R. Sobel
• Publisher：Geological Society of America
• Date：1999-
• Format：text/html
• Language：en
• Identifier：10.1130/0016-7606(1999)111<0709:BAOTJL>2.3.CO;2
• journal_abbrev：Geological Society of America Bulletin
• issn：0016-7606
• volume：111
• issue：5
• firstpage：709

The Jurassic through Cretaceous southwest Tarim basin, northwest China, contains more than 6 km of fluvial and lacustrine strata deposited in a foreland setting during the successive collisions with Eurasia of the Changtang block during Late Triassic–Early Jurassic time and with the mega-Lhasa block during Late Jurassic–Early Cretaceous time. This tectonism is chronologically linked with the creation of a narrow lower Middle Jurassic transtensional basin with thick sedimentary infill, succeeded by a broader Upper Jurassic–Lower Cretaceous compressional(?) basin with thinner sedimentary infill. The older basin formed between a north-northwest–striking dextral fault on the eastern side of the southwest Tarim basin in the Tian Shan and a postulated strike-slip or normal fault on the western margin of the basin along the Kunlun Shan. The former fault is now the Talas-Ferghana fault; the latter may be a predecessor to the Main Pamir thrust. Subsidence analysis of the thickest sedimentary section suggests thermal subsidence, interpreted as the result of transtension between the two basin-bounding faults. The younger basin extends farther east and west and does not preserve evidence of activity along the Talas-Ferghana fault. The change in basin style between these two episodes of basin development likely reflects either a small counterclockwise rotation of basin-bounding structures during the first episode or a small clockwise rotation of the maximum compressive stress between the two episodes.