In recent years，the exploration and development practices of the Ordovician Wufeng Formation and Silurian Lungmachi Formation in the Sichuan Basin and its adjacent areas have showed that shale gas has the characteristic of differential enrichment. Based on the TOC，XRD and elemental analysis results of the Wufeng?Lungmachi shale in the Sichuan Basin and its adjacent areas，combining with the relevant data published by previous researchers，we preliminarily analyzed the differential enrichment characteristics of organic matters in South，East and Northeast Sichuan areas，and discussed its controlling factors from the aspects of mineral composition（clay mineral content），preservation conditions and paleoproductivity. These conclusions can be reached from the study：1）The differential enrichment of organic matters has the following characteristics：In the depositional stage of the Wufeng Formation，the differential degree of organic matter enrichment is relatively low and the organic matter enrichment degree is slightly higher in East Sichuan than South and Northeast Sichuan；while in the early depositional stage of the Lungmachi Formation，the differential degree of organic matter enrichment is relatively high and the organic matter enrichment degree is significantly higher in Northeast Sichuan than South and East Sichuan. 2）Difference of preservation （redox）conditions is the main factor resulting in the differential enrichment of organic matters in different areas of the Wufeng Formation and Lungmachi Formation in the Sichuan Basin and its periphery.
Qiu Zhen Zhou Jie Lu Bin Zhang Chenchen Shi Zhensheng Dong Dazhong Wang Hongyan Lin Wen Jiang Zengguang Tan Xin. The main factors of differential organic enrichment of the Ordovician Wufeng Formation and Silurian Lungmachi Formation in the Sichuan Basin and its adjacent areas[J]. Chinese Journal of Geology, 2017, 52(1): 156-169.