新疆和田凹陷重力场与构造特征

The gravity field and tectonic feature at Hetian depression of Xinjiang

目的研究和田凹陷的构造特征。方法综合区域地质、地震等研究成果对实测重力资料进行定性及定量拟合计算,确定研究区发育地层及断层的分布特征。结果研究区山前及以南地区发育4条NWW向逆冲断裂,它们组成山前叠瓦式逆冲断裂系;和田凹陷发育的盖层为原地系统,推覆前缘断褶带内为双层结构,上部为外来系统,下部为原地系统。结论研究区发育地层呈NWW(EW)向,局部构造主要发育于和田断裂与铁克里克北缘断裂之间;山前推覆构造由南向北依次为根带、第二冲断席、第一冲断席、前陆盆地变形微弱盖层,推覆构造在中新世—更新世期间形成。

Aim To study the tectonic feature at Hetian depression. Methods Through the qualitative and quantitative fit computation for gravity data observed synthetized regional geological and seismic research achievements concerned, confirm the distribution feature of fault and stratum developed in the study area. Results 4 thrust faults in NWW direction developed, which composed the imbricated thrust fault system in the piedmont and the southern part of the study area. The cover layer in Hetian depression is an autochthonous system, it＇s the duplex-layer structure in the fault-folding belt at the front of the trust nappe, the upper is an allochthonous system and the lower is an autochthonous system. Conclusion The strata developed are in NWW（EW） direction in the area, the local structures developed are mainly between Hetian fault and Tiekelike fault. The nappe structure are the root zone, the second thrust sheet, the first thrust sheet and the foreland basin weak-deformed cover layer from south to north respectively. The thrust structure was formed in the period of Miocene and Pleistocene.