Occurrence And Metallogenic Mechanism Of Silver In Yindonggou Silver Deposit,Hubei Province

The Yindonggou silver deposit in Hubei Province is located in Yindonggou village,Zhushan County,Shiyan City,Hubei Province.The geotectonic location of this area is located in the southern margin of the eastern Qinling geosyncline and the northwest corner of Wudang anticline.The whole mining area is mainly NW and NE trending structure.Based on the detailed field investigation of the Yindonggou deposit,combined with the interpenetration of obvious veins and the symbiosis and association of minerals in the mining area,combined with the microscopic observation and electron probe analysis,The metallogenic period of Yindonggou silver deposit is divided into two stages: Hydrothermal metallogenic period and supergene oxidation period.According to different characteristics,the hydrothermal mineralization is divided into three stages: lead zinc mineralization stage,silver polymetallic mineralization stage and low temperature mineralization stage.The occurrence state and location characteristics of silver in Zhushan Yindonggou deposit are studied,and the metallogenic mechanism in this area is explored.Through the study of Yindonggou deposit in Hubei Province,the main ore minerals are pyrite,sphalerite,galena and chalcopyrite;The main silver bearing minerals are argentite,argentite,chalcopyrite,chalcopyrite,spiral chalcopyrite and natural silver,and the gangue minerals are sericite and quartz.There are three types of silver minerals in Zhushan Yindonggou deposit,Hubei Province,which are:(1)inclusions of silver(2)intergranular silver(3)fractured silver.The first discovery of silver bundle mineral: concentrated red silver deposit,which is rarely developed in Yindonggou deposit in Zhushan,Hubei Province.The common concentrated red silver ore and pyrite coexist,and are located between chalcopyrite and quartz grains,with good crystal shape.According to the relationship between the content of FES in sphalerite and temperature,combined with previous studies,it is determined that the mineralization temperature of Yindonggou deposit is a medium low temperature hydrothermal deposit.It is found that the ions of the hydrothermal solution in the deposit mainly migrate in the form of chlorine complex in the early stage,and the temperature decreases in the process of upward migration,and gradually migrate in the form of sulfur hydrogen complex,It can be seen from figure(3-3)that after the hydrothermal solution entered the tectonic controlled shear zone,the temperature and pressure changed greatly,making the complexes of lead,zinc,copper and a small amount of silver in the hydrothermal solution unstable,gradually forming metal sulfides such as PBS,Zn S and Fe S2,Silver ions gradually combine with sulfur ions to form independent silver minerals.Sulfur ions are consumed in the early hydrothermal solution.Therefore,the early S elements are relatively abundant in the later stage of silver minerals formation,so it is shown that there are more s at the side,With the formation of silver minerals,s is consumed,so there is a phenomenon of more Ag and less s in the later stage,and silver ions continue to gather and finally precipitate as natural silver.