Sediment source area of early cambrian stone coal in Northeastern Hunan Province, China

There were a variety of high content elements associated with the early Cambrian stone coal in northeastern Hunan province, and the attribute characteristics were distinct. In order to find out the sedimentary sources of stone coal in this area, the contents of major elements and trace elements in 12 stone coal samples were determined by X-ray fluorescence spectrometer (XRF) and inductively coupled plasma mass spectrometer (ICP–MS). Based on the combination of major elements, content characteristics of trace elements, distribution characteristics of rare earth elements and geochemical parameters of related elements, the source regions of the early Cambrian stone coal deposits in northeast Hunan province were discussed. The results showed that the early Cambrian stone coal in northeast Hunan province was mainly composed of inorganic minerals, and the content of SiO₂ was the highest in the stone coal. The relationships between SiO₂ and other major elements (and other major elements) were not obvious, and the quartz mineral morphology was characterized by terrigenous input. The trace elements (V, As, Sr, Mo, Cd, Sb, Ba, Bi, U) in stone coal were obviously enriched. The distribution characteristics of rare earth elements and the relationship between Nb/Y–Zr/TiO₂ indicated that stone coal was influenced by neutral rock. La_N/Yb_N indicated that the deposition rate of stone coal deposits decreases from southeast to northwest. Means, the source comes from the eastern and southern directions; The w(SiO₂)/w(Al₂O₃), w(Al₂O₃)/w(Al₂O₃+Fe₂O₃), w(Al)/w(Al+Fe+Mn) and K₂O/Na₂O–SiO₂ structural discrimination models showed that the early Cambrian stone coal was deposited in the continental margin area, mainly receiving continental sources. Based on the comparison with the contents of rare earth elements, Rb, Nb and Pb in the middle-acid rocks of Shangshu Group distributed in the southeast direction of the study area, and the contents and combination characteristics of major elements in the magmatic rocks of Shuangxiwu Group, and combined with the evolution history of Jiangnan Orogenic belt, the middle-acid rock belt developed in the southeastern margin of Jiangnan orogenic belt was considered to be the source region of the early Cambrian stone coal deposits in northeast Hunan province. It was also one of the main controlling factors for the enrichment of trace elements in stone coal.