A Study of High-resolution Sequence Stratigraphic Characteristics and Coal Accumulation in Upper Paleozoic Strata of the Shanxian Coalfield
单县矿区高分辨率层序地层及成煤作用研究

Based on the principle of high-resolution sequence stratigraphy and an integrated analysis of the bore core and well logging, the authors divided different base level cycles of Upper Paleozoic strata in the study area. Four types of base level cycles were recognized: short, intermediate, long and extremely long. Through a comparative analysis, a high-resolution sequence framework was established. Researches show that the most favorable coal accumulation of the study area occurred at the special positions of the base level cycles (A/S close to 1), i.e., at the half level of the descending long base level and the late stage of the descending half level of the middle base level. According to the basin filling and the superimposition of different classes of base levels, the coal accumulation of the study area can be divided into early accumulation and late accumulation. The base level change of both accumulations and the course of basin filling evolution are analyzed in this paper.