Textures and structures of Sangshutal fault belt in Lishu fault depression it’s genetic mechanism
Song Lijun1,2, Liu Chiyang2, Guo Zhaojie3, Zhao Chunman4, Xu Hongjie4, Han Shuxia4, Qu Shaodong2, Li Li5
1. Oil Resources Faculty, Xi'an Petroleum University, Xi'an 710065;
2. Department of Geology, Northwest University, Xi'an 710069;
3. Center of Oil & Gas, Peiking University, Beijing 100086;
4. Science and Technology Development of Northeast Oil and Gas Branch, SINOPEC, Changchun 130062;
5. No.5 Institute of Geological and Mineral Exploring and Surveying of Shandong Province, Tai'an, Shandong 271021
Sangshutai fractures belt is in the western magin faul of Lishu fault depression,which consists of Sunjiatun fault,Xidingjia linkage fault,Sangshutai fault,Laosonglinzi linkage fault, north Jinshan fault and south Jinshan fault.In Huoshiling stage of Early Cretaceous,under the extensive environment of NW-SE,Sangshutai fault, north Jinshan fault and south Jinshan fault stretched intensely,and Sujiatun fault wasn't still active.In Shahezi stage of Early Cretaceous,Sangshutai fault, north Jinshan fault and south Jinshan fault stretched strongly,Laosonglinzi linkage fault between the above the faults was active,and Sujiatun fault also began to act,under the sinisterly strike-slip environment.Under the dextral strike-slip environment,Sujiatun fault and the northern part of Sangshutai fault were all extending strongly,the south Jinshan fault and Laosonglinzi linkage fault were in highly compression in Yingcheng stage of Early Cretaceous.From Denglouku stage to early Quantou stage,Sujiatun fault,Sangshutai fault,Jinshan fault and Laosonglinzi linkage fault were in transtensional strike-slip.This movement became weaker apparently and almost stopped in early Quntou stage of Early Cretaceous.So,it was covered by the thick upper Quantou Formation and Upper Cretaceous.From late Nenjiang stage to Mingshui stage,Laosonglinzi linkage fault slipped strongly and upperly cutted the Upper Cretaceous,under the NW-SE compression environment.