STRUCTURAL ANALYSIS ON CENOZOIC FOLD-AND-THRUST BELTS IN KASHI AREA,WESTERN TARIM BASIN
Miao Jijun1, Jia Chengzao2, Hou Xianghui3, Wang Zhaoming3, Zou Caineng2, Tang Liangjie1, Song Yubin2
1. Basin and Reservoir Research Center, China University of Petroleum, Beijing 102249; 2. Research Institute of Petroleum Exploration and Development of China, Beijing 100083; 3. Tarim Oilfield Branch Company, China National Petroleum Corp., Korla, Xinjiang 841000
Based on accurate structural analysis of four seismic profiles across Kashi area in western Tarim Basin,a tectonic model for Cenozoic fold-and-thrust belts in the area was established.The area was controlled by southward thrusting of the Chinese South Tianshan in Late Cenozoic,in addition,the area was influenced by northward thrusting of the West Kunlun mountains.Namely,the Cenozoic fold-and-thrust zone there could be divided into two parts: the northern part attached to the foreland thrusting system of the Chinese South Tianshan,and the southern one to the foreland thrusting system of the West Kunlun mountains.The former was named the Artux foreland fold-and-thrust belt in the paper,which was composed of three rows of main thrusts and related anticlines,and their evolutional process was briefly discussed.By technique of balanced section,the structural shortening was calculated,which was more than 43.7 km in the northern part and 4 km in the southern part respectively,with a total shortening ratio of the profile being fifty percent.To synthesize regional tectonic evolution and reservation conditions,it was thought that the relatively better potentials might be deeper layers in the northern part(the Artux fold-and-thrust belt),and the key factor for oil-gas exploration should be good-quality reservoirs there.