ABSTRACT: Tectonostratigraphic Paleoreconstruction of China

Hugh J. Mitchell-Tapping

In many instances, global paleoreconstruction of the continents has depicted China as one continental plate throughout geologic time. Actually, Paleozoic and Mesozoic China was a mosaic of continental island plates dispersed in Proterozoic and Paleotethys seas. The movement of these island plates was controlled on the major part by the movement of the Siberian craton (Angara shield) and to subduction and accretion of oceanic plates to the east and south near the present-day Tibetan plateau. During the late Paleozoic and early Mesozoic many of these island plates moved together toward the east, accreting and thrusting upon each other. Many of these collisions occurred obliquely, causing large suture zones and low-angle thrusts, especially in the area of present-day south C ina. The Tertiary collision and overthrust of the Indian plate in the region of Tibet was preceded by an accretion of two large oceanic plates over which a southern oceanic plate has overridden the northern accreted plate. Subsequently, this caused the megauplift of the present-day Tibetan plateau by being underridden by both the proto-Indian and Indian plates. There is evidence from age-dating basement rocks in southern onshore and offshore China that most of the grabens, the fold systems, and the coastal foldbelt as proposed on many maps may be interpreted as areas of Paleozic and Mesozoic low-angle thrusting, together with extensional strike-slip movements, covered with Cenozoic nonmarine (fluvial and lacustrine) sediments. Paleofacies maps of China have been constructed based on a sy thesis of basin lithofacies stratigraphies that support this interpretation.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990