FORMATION ENVIRONMENT AND DISTRIBUTION OF ORGANIC-RICH SHALES IN YUNNAN PROVINCE

The geological background, forming ages and characteristics, target strata, forming environment and distribution regularity of shales in Yunnan Province are studied on the basis of a large number of literatures. The results show that the exploration should focus on the Lower Cambrian Qiongzhusi Formation, Lower Silurian Longmaxi Formation, Upper Silurian Yulongsi Formation and Upper Triassic Xujiahe Formation. The potential shales of Qiongzhusi Formation formed in the continental shelf environment are mainly distributed in western, north central, eastern, northeastern and southeastern Yunnan, while those of Longmaxi Formation are only occurred in western, north central and northeastern areas due to large-scale regression. With the continuous large-area regression in the east and northeast, the potential shales of Yulongsi Formation are confined to Qujing-Malong-Kunming-Chengjiang areas, and those of Xujiahe Formation formed in continental environment mainly in the central subarea and Lanping-Simao area.