Research on coal-accumulation features in Late Permian sedimentary system and sequence stratigraphic framework, Northeastern Yunnan, China

The authors analyze Late Permian sedimentary system and its spatial distribution and evolution in study area based on the lithofacies associations, sequence of sedimentary structure and biological fossils of the stratigraphic sections. On the basis of results above, Late Permian sequence stratigraphic framework is established according to identifying sequence and system tract interface under different paleogeographical backgrounds. The authors summarize spatial superimposed position and formation mechanism of coal seams and sulfur distribution features in coal seams. In addition, they discuss coal-accumulating features and locations about the thick coal seam (C5) under the framework of sequence stratigraphy. Combining with latest exploration data, the authors predict that there are enormous potential resources of high-quality coal on Yanjin-Yiliang region in midwest of study area, and they emphasize increasing the coal-geological exploration investment on predicted target areas at the same time of keeping exploration and development on coal resources Weixin-Zhenxiong region in east of study area.