赣南峰山离子型稀土矿床成矿机理探讨OA北大核心CSTPCD

The representative borehole drilling through the weathering crust at Fengshan in southern Jiangxi Province is selected as the research object in this paper.Based on the geological characteristics of each layer in the weather-ing crust,the characteristics of major and trace elements(including rare earth)and ionic-phase rare earth elements in each layer of the weathering crust are comprehensively discussed.The rare earth-bearing minerals in each layer of the weathering crust are analyzed by scanning electron microscopy and electron probe microanalysis.The dis-tribution of rare earth elements in the weathering crust shows an"arching"pattern.The ore body is located 2 to 9 m below the surface in the weathering crust.The average total rare earth elements(including Y)is 516.8× 10-6,the leaching rate of ionic phase rare earth elements is 51％～84％,and the distribution patterns of the ionic phase rare earth elements are consistent with those of the total phase rare earth elements.The rare earth elements in the weathering crust are in the form of ion adsorbed state and independent minerals such as secondary cerianite,resid-ual xenotime and fergusonite,the ion adsorbed state is dominant.The Fengshan REE deposit is characterized by coexisting LREE and HREE,with a dominance of heavy rare earth elements.The upper part of the ore body is rela-tively enriched with LREE,and the lower part is enriched with HREE.The enrichment and differentiation of REE in weathering crust is mainly controlled by the difference of geochemical behavior of LREE and HREE,weather-ing degree and clay mineral content.