SU Yonghu1,2,3, DU Lin2*, JIN Zhongguo4, GUN Minshan2, ZHENG Minghong4, ZENG Daoguo2, XIANG Mingkun2, XUE Hongfu2, GONG Xin2
(1. College of Resource and Environment of Guizhou University, Guiyang 550025, China;
2. Geological and Mineral Exploration Institute, Non-ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou, Guiyang 550005, China;
3. Geological Data Information Center, Non-ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou, Guiyang 550005, China;
4. Non-ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou, Guiyang 550005, China)
Abstract: The Wuchuan－Zheng’an－Daozhen area is an important bauxite deposit concentration area in Guizhou Province, with over 700 million tons of submitted bauxite reserve. The bauxite ore in the area is hosted in the Lower Permian Dazhuyuan Formation, in which REE is widely enriched. Due to the significant controversy over the enrichment patterns and occurrence states of rare earth elements in those bauxite-bearing rocks, it is still lack of practical theoretical basis for comprehensive utilization and geological exploration of REE resources. Based on the study of the geological characteristics of the bauxite ore-bearing rocks in this area and the geochemistry of associated REE in those rocks, we have summarized and analyzed geochemical characteristics and enrichment laws of the REE in the bauxite ore-bearing rocks and discussed occurrence forms of the REE in those rocks. The research results indicate that the bauxite ore-bearing rocks in the Wuchuan－Zheng’an－Daozhen area have basically right declined REE distribution patterns with obviously enriched LREE and obviously negative Eu anomalies. There are positive Ce anomalies for samples in the upper and middle parts of this set of bauxite ore-bearing rocks, while there are negative Ce anomalies for chlorite mudstone samples in the bottom part. In general, REE contents of bauxite ore-bearing rocks in the northwestern and southeastern parts of the syncline in the study area are relatively high, while those of samples in the central part of the syncline are relatively low. The REE mainly occurred in the chlorite mudstone at the bottom. The REE in the bauxite ore-bearing rocks could occur mainly in forms of ion adsorption on the surface or isomorphic replacement in the lattice of aluminum minerals and clay minerals. In addition, the REE also could occur in the form of independent mineral. This study provides geological and geochemical basis for the geological exploration and comprehensive utilization of the REE resources in bauxite ore-bearing rocks.
Keywords: REE; enrichment regularity; occurrence forms; the bauxite ore-bearing rocks; the Wuchuan－Zheng’an－Daozhen area
