天山南缘逆冲构造初探

PRELIMINARY APPROACH ON THRUST TECTONICS IN SOUTH MARGIN OF TIANSHAN MOUNTAINS

该构造在区域上受控于南北向水平挤压应力场。逆冲断裂在横向剪应力作用下,宏观上呈现为扇形或倒扇形构造的特点。其时空特征为:自北而南依次展布着海西期逆冲断裂、印支—燕山期叠瓦构造和喜马拉雅期推覆构造,后期对前期构造既叠加又改造。

The thrust tectonic belts in the south margin of the Tianshan Mountains were region-ally controlled by N-S horizontal compressing stress field,thus forming E-W stretchingfold-faulted tectonics.Those are macroscopically characterized by fan or reverse fanshapes.The belts could be divided into three kinds:1.thrusts mainly formed in Hercynianand distributed in the south flank of the Halicktao anticlinorium;2.imbricate tectonicsformed in Indosinian-Yenshan Epoch and distributed in the fore part of south Tianshan;3.nappe tectonics characterized by thrusting up to several kilometres along sliding planesat low angles,developed in Himalayan Epoch and distributed in foreland depressions andthe neighbouring intermontane basins.It is a intensive reformation to the thrust tectonicsof the Hercynian and Indosinian-Yenshan Epoches.