铝土矿型富锂黏土的物源属性及其富锂机制OA

[Objective]Lithium rich claystone deposits with great potential for mineralization have been found in the bauxite-bearing sedimentary strata of Yunnan-Guizhou region in Southwest China,but the current understanding of the material sources and lithium enrichment mechanisms of these bauxite-type lithium rich claystones in these areas is still significantly insufficient.[Methods]In this study,two sets of bauxite-type lithium rich claystone systems,the Early Permian Daoshitou Formation in Yunnan and the Lower Carboniferous Jiujialu Formation in Guizhou,were ana-lyzed in terms of their mineralogical compositions,major and trace elements,and the compositions of rare earth ele-ments.Combined with the results of previous research,the study systematically explored the source attributes of two sets of bauxite-type lithium-rich claystone systems,which were formed in different epochs but have very similar petro-graphic characteristics,as well as determining the factors that led to the anomalous enrichment of lithium.[Results and Conclusions]The results showed that the differences in source properties between the lithium rich claystones of the Jiujialu Formation in Guizhou and the Daoshitou Formation in Yunnan had a significant influence on their lithium content.In general,the development of the Jiujialu Formation,which has relatively low lithium content,is closely related to the weathering and denudation of impure dolomite in the underlying Loushanguan Group.Its original source may have been Neoproterozoic-Middle Proterozoic neutral acidic magmatism,which is significantly influenced by Mg-Fe compositions.The formation of Yunnan Daoshitou Formation claystones with relatively high lithium content was significantly influenced by the recycling of Ordovician sedimentary rocks,while the source connection with its under-lying carbonate strata was weak.Their original source was dominated by neutral acidic magmatism.In addition,the lithium rich clay rocks in the Yunnan-Guizhou region were hosted by either kaolinite or illite,and the drainage of the watershed during the depositional period and the effect of coexisting ions in the water body played important roles in restricting the lithium enrichment in the clay.Analyzing the provenance of lithium rich clay rocks in the Jiujialu For-mation in Guizhou and the Daoshitou Formation in Yunnan,along with the occurrence of lithium-bearing minerals,is of significant importance for understanding the ore-forming processes and controlling mechanisms of clay-type lithium deposits.