马家滩矿区延安组层序-古地理对煤岩煤质的控制

以宁东煤田马家滩矿区为研究对象，进行层序的划分与对比，建立马家滩矿区延安组层序地层格架，以三级层序为单元，恢复各层序的古地理格局。结合矿区煤岩煤质分布规律，发现煤岩煤质的平面和垂向分布特征受层序-古地理控制作用明显。平面上，矿区南部形成于三角洲平原环境的煤层镜质组含量较高，受物源区的控制，灰分分布北高南低。垂向上，不同层序间随着沉积环境的演化，煤岩组分和灰分随之变化；同一层序不同体系域对煤岩组分含量的影响具有分段性，湖侵体系域后期最有利于镜质组形成，低位体系域则不利于镜质组的形成。 

The controls of sequence-paleogeography on coal petrology and quality of Yan'an Formation in Majiatan mining area

With Majiatan mining area as the research area, the sequence stratigraphic framework of Yan'an Formation in Majiatan mining area is established by the division and comparison of sequence, and then the sedimentation paleogeographic features of each third-order sequence were reconstructed. With the study on the distribution of coal petrology and quality, it is found that the plane and vertical distribution characteristics of coal petrology and quality are obviously controlled by sequence and palaeogeography. On the plane:the vitrinite content of the coal seam is higher in the delta plain environment in the south of the mining area, and the ash content is decreasing from the north to the south gradually by the control of the source area. Vertically, the composition and ash of the coal are changing in different sequences with the evolution of sedimentary environment. In the same sequence, the influence of different system tracts on the content of coal and rock components is segmented. The most favorable vitrinite formation is in the later stage of transgressive system tract, and the low level system tract is the most unfavorable to the formation of vitrinite.