鲁西地区石炭纪—二叠纪煤系关键金属富集特征及其控制因素OA北大核心CSTPCD

Critical metals are essential strategic resources,and their presence in coal-bearing strata has become a research hotspot in the fields of coal geology and ore deposit studies both domestically and internationally. Several coalfields in western Shandong Province have been identified as enriched in critical metal elements. This study builds upon previous research on trace elements in the area to determine the enrichment characteristics and influencing factors of critical metals in the coal measures of western Shandong. Using inductively coupled plasma mass spectrometry (ICP-MS),we measured the content of critical metals in the coal seams of the Yanzhou and Jining coalfields and analyzed their distribution patterns across western Shandong. Our findings reveal distinct enrichment zones for various critical metals. The Yanzhou coalfield,the southern part of the Ningwen coalfield,the northern segment of the Jining coalfield,and the western portion of the Juye coalfield display enrichment in Li,Se,Zr,and Hf,with these enrichment layers consistently located in the Shanxi Formation. The southern part of the Tengxian coalfield exhibits enrichment in Ga and Ge. Ga enrichment is observed in both the Shanxi and Taiyuan formations,while Ge enrichment is restricted to the Taiyuan Formation. The Feicheng and Xinwen coalfields demonstrate enrichment in Li and Ge,with Li enrichment layers present in both the Shanxi and Taiyuan formations,and Ge enrichment confined to the Taiyuan Formation. Our analysis suggests that terrigenous materials and hydrothermal fluids/groundwater are significant sources of critical metal elements in western Shandong. The Yinshan upland and the Qinling orogenic belt are the primary sedimentary source areas for the Carboniferous-Permian coal measures in western Shandong. Lithium emerges as the most widespread and highly enriched critical metal in western Shandong,with hydrothermal fluids being the main controlling factor for its enrichment. Additionally,seawater appears to have contributed to the enrichment of critical metals such as U,V,Cr,and Tl in the Taiyuan Formation coal-bearing strata in western Shandong.