Structural accommodation zones in the main extension period and their effects on depositional system in the Shenxian Sag, Jizhong Depression
Liang Fukang1, Liu Liping2, Yu Xinghe3, Huang Yong4, Tang Hua5
1. Department of Mineral Resources Assessment, China Shenhua Overseas Development & Investment Co.Ltd., Beijing 100011;
2. Production Department, Shenhua Geological Exploration Co.Ltd., Beijing 100011;
3. School of Energy Resources, China University of Geosciences, Beijing 100083;
4. School of Earth-Sciences and Resources, China University of Geosciences, Beijing 100083;
5. Xi'an Institute of Geology and Mineral Resources, Xi'an 710054
Structural accommodation zone,which is the main type of transfer zone,controls the sediments migration path and surface exhibition in the Shenxian Sag,Jizhong Depression.According to the characteristics of the faults combination(such as dip relation)and throw,four categories, 4 kinds of structural accommodation zones can be summed up.Controlled by basic structural configuration,single line and synthetic accommodation zones,which are relatively small and numerous,mainly develop in the northern part area,such as in Hezhuang,Bingcao and Cuijiazhuang.Convergent accommodation zones,however,which are larger and sparse,mainly formed in the southern part area,such as Yuke and western Zhaojiazhuang.Divergent accommodation zones are rarely found in the Shenxian Sag. Single line accommodation zones may allow minor sedimentary bodies acrossing faults and reaching faulted lake,such as subaqueous fans developed in downthrown side of Hengshui fault.Synthetic accommodation zones control the transportation path into the catchment basin and spread of braided delta in Hezhuang-Xiweicun, Tianjiazhuang, Dongyangxiang. Convergent accommodation zones usually lead to the formation of deep lake,for example in Zhaojiazhuang. Besides, Divergent accommodation zones usually block the sediment transportion by topographic high.