Sedimentary Environment of Coal Strata in Northern Anhui Province, China:A Case Study in the Qidong Coal Mine

Sedimentary environment studies were defective in coal mining areas, which seriously restrict to understand more about the coal-bearing environment. In this study, the sedimentary environment of coal strata (from P to C3) in the Qidong coal mine was identified via geochemical methods. The samples are enriched in SiO₂, Al₂O₃, Fe₂O₃ of major oxides and Ba, Ce, Sr, V, and Zr of trace elements. The Sr/Ba and Rb/K ratios of the samples show that the sedimentary environment of the Qidong coal mine changed from the marine to the continental facies, and there might be a river near the study area during this period. The δCe, La/Ce, V/Cr and Th/U ratios indicate that the Qidong coal mine was formed in a redox environment. REE was used to distinguish tectonic background, and the results manifest that the tectonic background of NCC’s (North China Craton) south edge wase passive continental margin in this period.