DEVELOPMENT AND EVOLUTION OF THE STRIKE-SLIP FAULTS IN SHUNNAN AREA, TARIM BASIN

Shunnan area, located in the northern Tazhong uplift of Tarim Basin, is affected by multi-stage tectonic stress with a large number of developed strike-slip faults. Detailed interpretation and deep analysis of 3D seismic data show the faults are varied in vertical and plane views with multi-stage structural superposition. There are mainly 3 groups, i.e. NE, NEE, and NW, of strike-slip faults developed in the study area. The NE-trending faults are highly active, with en echelon and horsetail structures developed on the plane, and composite flower structures of symmetric flower, positive and negative flowers superimposed on the profile; while the NEE and NW faults are less active, with single vertical strike-slip fault dominated on the profile, and linear extension or multi-section synthetic strike-slip faults connected on the plane. According to the structural style and stress property, the FSN1 can be divided into 4 segments along the strike, including 2 composite flower-tensional segments and 2 simple flower-compressional segments, which occur alternately along the strike. The strike-slip faults mainly went through 5 stages of tectonic movements:the Early Caledonian, Episode I of Middle Caledonian, Episode Ⅲ of Middle Caledonian, Late Caledonian-Early Hercynian and Late Hercynian, among which, the second and third are the main stages for fault activity.