Comparison of Tarim and Central Asian FSU Basins, I: Phanerozoic Paleogeography

Christoph Heubeck and Shangyou Nie

Large amounts of previously unpublished data on the petroleum geology of the FSU's Central Asian Republics and of China's Tarim region have found their way into the western public domain in the past few years. These data provide for the first time the opportunity to merge detailed stratigraphic, tectonic, and paleogeographic studies done during the past decades on both sides of the FSU-Chinese border and to place the results in a plate-tectonic and palinspastically restored reference frame.

Major tectonic events affecting the active post-Silurian south-facing margin of Asia between the Caspian Sea and Tarim include (1) the collapse of the Kazakhstan arc fragments (ca. 400-300 Ma); (2) collision of Yili with Tarim (ca. 375 Ma); (3) consolidation of the Turan Platform from pre-existing basement blocks (ca. 280-220 Ma), (4) collision of Tarim/Yili with the Kazakhstan arcs (ca. 260 Ma); (5) stabilization of a south-facing Triassic active margin (ca. 250-200 Ma); (6) accretion of Cimmeria (ca. 200 Ma) and associated reactivation events in Turan, Syr-Darja, and Tarim; (7) reactivation and modification of intracontinental structures during the collision of central Asia with India (ca. 55 Ma to present) and with the Arabian platform (ca. 25 Ma). Periodic large-scale flooding of denuded continental platforms (Turan, Tadjik) during sea-level highstands is recorded in the Jurassic, Mid-Late Cretaceous, and the Early Tertiary, resulting in extensive tracts of restricted marine sedimentary systems and marine incursions deep into central Asia (SW Tarim, Kuche Depression, Fergana, Turgay). Mesozoic-Cenozoic source rocks are sensitive to rapid lateral facies changes, and understanding their distribution requires detailed stratigraphic analysis. The attempted synthesis of data from China and the FSU with plate-tectonic concepts allows the transfer and testing of play concepts and hydrocarbons systems across the FSU-Chinese border.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California