Kuqa Late Cenozoic fold-thrust belt in the southern flank of Tianshan Mountains

Kuqa Late Cenozoic fold-thrust belt in the southern flank of Tianshan Mountains comprises of several structural zones trending E-W. Regional decollement faults are developed in the Triassic dark mudstone, Jurassic coal-bed Paleogene Kumugeliemu gypsum-salt and Neogene Jidike gypsum-salt. The bottom main decollement fault of the fold-thrust belt rises step by step southward. Cover decollement-thrust (thin skinned structure) developed in the major part of the belt, and basement-involved thrusts (thick skinned structure) can only be seen in the root zone at the north margin of the belt. The deformation above the Cenozoic gypsum-salt is characterized with decollement fold and that under the Cenozoic gypsum-salt is characterized with thrust. Kuqa fold-thrust belt was resulted after the Cenozoic (South) Tianshan Mountain building under the far-field effect of the India-Asia collision. The main force resource of the folding and thrusting is the compressive structural force induced by the southward propagation of the (South) Tianshan orogenic wedge. The folding and thrusting began since ca. 23Ma, and then accelerated at ca. 10Ma, 5 similar to 2Ma and 1 similar to 0Ma. The evolution of Kuqa fold-thrust belt is in the way of forward propagation. While the front of the belt propagates southward, the hinter parts continue folding and thrusting.