Sedimentary characteristics and coal-accumulation pattern analysis of Badaowan Formation in southern margin of Junggar Basin, Xinjiang

Abstract：Using theories of classic sequence stratigraphy and modern sedimentology, the authors analyzed the data of drill holes, loggings, cores and palaeontology with the purpose of investigating sedimentary characteristics and coal accumulation of the Badaowan Formation in the southern margin of Junggar basin. Based on sequence stratigraphic analysis of the single well, the authors divided Badaowan Formation into two sequences, namely SQ1 and SQ2, both of which have the tripartite structure, corresponding respectively to the lower and upper segment of Badaowan Formation in the coalfield. According to the well-connecting profile, the authors established sequence stratigraghic framework, then made a plane analysis of the sedimentary facies of each system tract, and finally analyzed the coal accumulation. It is found that the principal seam of the coalfield developed mainly at the last stage of LST and the initial stage of HST, and the delta plain area is the optimum place for coal accumulation. These results will certainly provide some guidance for the further establishment of coal exploration area.