THE GEOTECTONIC ENVIRONMENT OF LONGTAN COAL-FORMING PERIOD IN HUNAN PROVINCE

The Longtan coal-bearing formation in Hunan is deposited in the late of Early Permian-early of Late Permian, with the complex depositional patterns. In the middle and southern part of Hunan,there are two terrigenous supply ares in the east and west sides of the Shuangpai-Changshou fault. Based on the study of the Longtan coal bearing formation distribution, sedimentary environment evolution, lithofacies distribution, magmatic activity,sturctural analysis,mineralogic component and chemical composition of the sandstones,it is pointed out that the geotectonic environment in Hunan is a passive continental margin with the stronger activity in the late of Early Permian-early of Late Permian.