Coal-accumulating environments of the Upper Carboniferous-Lower Permian Taiyuan Formation in southeastern Qinshui Basin, Shanxi Province
Wang Baoyu1, Hu Bin2, Bai Jianping1, Yang Lianchao3
1 National Energy Key Laboratory of Coal and Coal-bed Methane Simultaneous Extraction,Jincheng 048006,Shanxi; 2 Key Laboratory of Biogenic Traces and Sedimentary Minerals of Henan Province,Jiaozuo 454003,Henan; 3 Shanxi Lu'an Environmental Energy Development Co.,Ltd.,Changzhi 046204,Shanxi
Abstract：The Upper Carboniferous-Lower Permian Taiyuan Formation in Qinshui Basin contains important mineable coal seams and coalbed methane resources,and is well exposed in Fucheng town of Lingchuan County in southeastern Qinshui Basin,Shanxi Province. Based on the outcrop section observation and a part of borehole data of the Taiyuan Formation,the paper synthetically analyzed the lithologic features,sedimentary structures,body fossils,trace fossils,sedimentary sequence and some other depositional characteristics.(1)Carbonate rocks of the Taiyuan Formation in this area were formed in two sedimentary environments,i.e.,open shallow sea(open platform)and restricted bay(restricted platform),among which,the top of Limestone 1(L1),middle-lower part of L2,the upper part of L4,the top of L5,the top of L7 and the L8 were formed in a restricted bay environment,and other limestone beds were generated in an open shallow sea environment;(2)Based on the lithologic association characteristics of the Taiyuan Formation coal measures in the study area,six lithologic members were classified,and clastic rocks and coal seams in each member mainly were formed in sedimentary environments including barrier island(sand island),lagoon and tidal flat;(3)After analyzing sedimentary characteristics and sedimentary sequence,11 types of sedimentary sequences were distinguished and 3 types of coal-accumulating environment modes were proposed in the Taiyuan Formation coal measures of this area,including coal-accumulating environment of tidal flat associated with barrier island and lagoon depositional system,the coal-accumulating environment of tidal flat alongside restricted bay(lagoon),and the coal-accumulating environment of coastal tidal flat. The results may provide important information and theoretical supports of sedimentary background for coal and coalbed methane exploration and developing in the Taiyuan Formation of southeastern Qinshui Basin.
Wang Baoyu,Hu Bin,Bai Jianping et al. Coal-accumulating environments of the Upper Carboniferous-Lower Permian Taiyuan Formation in southeastern Qinshui Basin, Shanxi Province[J]. JOPC, 2015, 17(5): 677-688.
