Characteristics Of Active Tectonics And Remote Sensing Images In South Tian Shan, Northwestern China

Tian Shan extends east-west in central Asia, the Tian Shan Range was formed in later Paleozoic, and a few intramontan basins appeared in Mesozoic. It uplifetd again in early Miocene because of the north-south compression induced by the India-Asia collision, so many active structures can be found in Tian Shan.Active tectonics took actions during last ten thousands yeas, and surface traces of fault scarps, detached gullies and folds in alluvial deposit are apparent, so it is easy to distinguish them from other geological phenomema.Interpreting the remote sensing images and verifying the facts in south Tian Shan, we studied active tectonics of Yanqi basin, Aheqi fault and Kuche depression.Yanqi basin is an intermont basin of Tian Shan, there is a NWW trending right lateral strike slip active fault in southwestern basin, its maximum slip distance is 210m, and slip rate is about 10mm/yr, moreover, there is a west-east trending active anticline along northern basin. Some controversy has been put on Aheqi fault, our data shows it is a NE trending left lateral strike slip fault, but its activity is weak. Kuche depression is a foreland depression, thrust-anticline structure is its main form, and the newest active fold is Yaken anticline, and fault is Qiulitage fault.Analyzing collected dada, the conclusion is:Northwestern trending right lateral strike slip faults are predominant, other active structures include northeastern trending left lateral strike slip faults and west-east trending folds.Thrust faulting and folding are main structures in the south piedmont of Tian Shan, they are migrating southward to Talimu basin.Crustal shortening of Tian Shan is centered in foreland depression, but we also think about shortened length of intermont area.