JURASSIC TECTONO-SEDIMENTARY SETTING OF THE YINGJISU SAG, NORTHEASTERN TARIM
Hu Jianfeng1, Li Yuejun2, Zheng Duoming3, Peng Gengxin3, Sang Hong3, Jin Ying’ai3
1. Faculty of Natural Resources and Information Technology, University of Petroleum, Beijing 102249; 2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029; 3. Tarim Oilfield Branch Company, China Natural Petroleum Corp., Korla, Xinjiang 841000
The Yingjisu Sag, situated in northeastern Tarim Basin, was a part of the Central Asia-NW China superlarge Basin in Jurassic, and a cratonic basin (intracontinental depression) formed in Early Jurassic. Based on the recent data of drilling wells in central-northeastern Tarim, a seismic profile across the sag, Q-F-L components and REE patterns of the sandstones, the Jurassic tectono-sedimentary setting of the sag was discussed. The north boundary of the sag might reach to the Kruktag area during that time, and the sedimentary debris come from a fossil orogen to the south, which was composed of the Jinningian granodiorite-diorite, as well as the Lower Paleozoic. To be influenced by the Yanshanian movement, the sag closed and the Jurassic was reformed by the faults in the southern and central parts of the sag. In Cretaceous, the Yingjisu Sag deposited again as a part of the North Depression of Tarim Basin. In Cenozoic, the North Depression changed to be an intracontinental foreland basin with creation of the South Tianshan and Kruktag mountain chains, and thrusting of the Kongquehe fault made the Jurassic in the Yingjisu Sag reformed once again.