贵州西部二叠系主采煤层稀土元素分布特征及影响因素分析Distribution Characteristics and Influence Factors of Rare Earth Elements in Guizhou Permian Coal Measure Strata
稀土元素, 沉积环境, 主采煤层, 二叠系, 贵州西部Rare Earth Element, Sedimentary Environment, Major Exploitable Coal Measure, Permian, Western Guizhou
《Advances in Geosciences》, Vol.5 No.4, 2015-08-18
Guizhou has abundant coal resources which is an important coal production base in China, but few researches have been done on the element geochemistry of coal measure strata in Guizhou Province, and the effective utilization of coal resources in Guizhou is a serious defect. Based on element geochemical studies of the main Permian exploitable coal measure strata in western Guizhou, geochemical distribution characteristics of the rare earth elements in the main exploitable coal measures have been revealed in the regions of Dafang, Qianxi, Weining, Heizhang, Zhijin, etc. of Guizhou province. The REEs in coals are mainly continental origin, associated with Emeishan basalt. Contents of REEs in coal seam are affected by sedimentary environments and lithology qualitative in terrigenous areas. REEs are gradually diluted from delta plain environment, which contains more basalt weathering debris, to the tidal flat environment greatly influenced by the water. The contents of REEs are higher when coal-forming environment is closer to land, while the contents of REEs are lower when coal-forming environment is away from land. According to the rules of distribution of REEs in coal measures, a new idea has been put forward to make use of the geo-chemical composition characteristics to classify coal-forming environments, which is of great sig-nificance in dissolving the problem of whether coal measures were formed either in delta envi-ronment or in tidal-flat environment in western Guizhou.