LATE CENOZOIC TECTONICS ALONG THE NORTHWESTERN MARGIN OF THE TARIM BASIN: INTERACTIONS BETWEEN THE TARIM BASIN AND THE SOUTHERN TIAN SHAN, WEST CHINA

摘要

The Late Cenozoic fold|and|thrust zone along the northwestern margin of the Tarim Basin and the adjacent Tian Shan of Central Asia is an actively deforming part of the India|Asia collision system. This deformation zone has two remarkable oppositely vergence arcuate fold|and|thrust systems (Kepingtage and Kashi|Atushi fold|and|thrust belts) reaching from east of Keping to west of Kashi. This shape is manifested by structure, topography and seismicity. From north to south, this deformation zone is characterized by four main kinematic elements: (1) a hanging|wall block (Maidan fault and Tuotegongbaizi|Muziduke thrust system) that represents the Cenozoic reactivation of a late Paleozoic thrust system; (2) an imbricated thrust stack (Kepingtage|Tashipeshake thrust system) where slices of Tarim platform sediments are thrust south toward the basin; (3) the Kashi|Atushi fold|and|thrust system where thrusting and folding verge toward the Tian Shan; (4) a foot|wall block (Tarim craton) that dips gently northwest below the sediment|filled southern Tian Shan basin and generally has little internal deformation.