CHARACTERISTICS OF THE TECTONIC MOVEMENT SURFACE BETWEEN THE CARBONIFEROUS AND THE UNDERLYING SEQUENCES IN THE TARIM BASIN

The unconformity between Carboniferous and the underling sequences was a tectonic movement surface caused by Early Hercynian tectonic movement. It revealed the property, intensity and influenced scope of the tectonic movement. And it also represented a very important tectonic reversal event in the Tarim Basin. Using seismic section, fission track of apatite samples and vitrinite reflectance(R_o), the denudation thickness of the basin was restored. The results showed that the isopach strike of denudation thickness is nearly from east to west and it is similar to the direction of compressionalreversal structure of the basin. In the middle and north part of the basin the denudation was very intense, and the maximum denudation thickness could reach to 1 200 m. According to the distribution characteristics of the unconformity, the intensity of the tectonic movement was strong in the north and south, but was weak in the middle of the basin. Meanwhile it showed migration of tectonic uplift from south to north and from west to east in time succession.