Comparative Study On Strontium Deposit In Huayingshan Chongqing And Dafengshan Qinghai

Strontium deposits is the dominant mineral in China,but the study of strontium deposits is less in recent years.Chongqing Huayingshan and Qinghai Dafengshan are the main producing areas of strontium deposits in our country,choose two strontium deposit area as the research object,has important significance to enrich the content of research on strontium deposits.Based on the regional geological background,geological features,geochemical characteristics and the genesis of the deposit,this study carried out a comparative study of the two district Strontium deposits.A comparative study of the regional geological background of the deposits shows that both of the Strontium deposits are located in the faulted basin controlled by deep faults,and there were some faults and folds in the area.The difference was reflected in the extent of the ore deposits affected by the structure.Huayingshan strontium deposits are greatly influenced by tectonic stress,due to it,the strata tend to tilt at high angles,and associated with some secondary fracture.Dafengshan strontium deposit affected by the tectonism is lesser,and folds are more open and only a few small faults are developed,which have little effect on the orebodies.A comparative study of the geological characteristics of the deposits shows that the strontium orebodies in both areas are bedded or stratoid in layers,which are produced in a specific strata,controlled by strata and have the characteristics of sedimentary origin;The wall rock's sedimentary environment is different,the strata of Huayingshan is marine sedimentary,while Dafengshan is lacustrine deposition;There is a bigger difference in the crystallization degree of celestite,in Huayingshan the celestite is better crystallization,while in Dafengshan the celestite is microcrystalline and cryptocrystalline.This reflects the different environments for the formation of the deposits.Through the comparative study of the rare earth element geochemistry found that the celestite mineral of the two area's strontium deposits characteristed by the lower contents of?REE,especially LREE.The heavy rare earth elements in celestite are lower than the detection limit(<0.05×10^-6)in Huayingshan,which is similar with Dafengshan.Isotopic geochemistry study shows that in the two study area,the metallogenic substance of strontium deposits were supplied by continental and subsurface brines.Study on fluid inclusions in celestite of Huayingshan show that the deposit formed in the relatively high temperature and pressure environment,and Dafengshan strontium ore was not found fluid inclusions which indicate its formed in the open environment.Summarizing research achievements of predecessors and this study,the formation process of Huayingshan strontium deposit can divided into early sedimentary period,hot brine mineralization and supergene stage and Dafengshan is divided into evaporation deposition and post transformation period.For the ore forming process there is a greater difference between Huayingshan and Dafengshan,the main mineralization stage of Huayingshan is the hot brine mineralization period,while Dafengshan is evaporation period.