The Ore-forming Fluid Characteristic And Metallogenic Process Research Of The Linglong Gold Deposit In Jiaodong Region

Jiaodong Region is the most important gold Province in China. Sanshandao falult zone, Jiaojia fault zone and Zhaoping fault zone is the most important metallogenic belt located in Jiaodong Region. The Linglong gold deposit is a typical quartz-vein type gold deposits in China. The paper aims to summary the metallogenic processes of Linglong gold deposit by means of mineralogical study of fluid inclusions, combined with the analysis of deposits in the geological characteristics and metallogenic geological conditions. The main contents and opinions are described as follows:(1)Linglong gold ore fluid inclusions are mainly three types:Ⅰrich fluid inclusion;ⅡH2O-CO2 three-phase inclusions;Ⅲ CO2 two-phase inclusion. Three-phase inclusions of H2O-CO2 can also according to the proportion of CO2 in the inclusion can be further divided into Ⅱa rich water containing CO2 inclusions(CO2 than average less than 50%) subclass and Ⅱb rich CO2 inclusions(CO2 generally greater than 50%, compared to individual 80%) subclass.(2)Linglong gold ore forming temperature is 260-340℃; the salinity of the ore-forming fluid is mainly concentrated in 4-9wt % NaCl; metallogenic depth is 5 to 13 km.It belongs to the medium temperature of low salinity epithermal type gold deposit, through comparing with other diggings, its ore-forming physicochemical conditions(temperature, salinity, metallogenic depth and the fluid system);So Linglong gold deposit is the medium temperature low salinity epithermal type gold deposit.(3)The presence of CO2 in Fluid is the important guarantee for the enrichment of migration and precipitation of gold in Linglong gold deposit, immiscible effect of fluid and is the main factors of the fluid changes in chemical composition and mineralization.(4)Contrasting with other ore area, as well as different types of ore body, thant found that the results that both the altered rock type and quartz vein type ore body are NaCl-H2O-CO2 type hot liquid system of medium temperature low salinity;Further confirm the understanding of the two types of gold deposits of predecessors,two different types of gold deposit ore-forming physicochemical conditions is no essential difference, well it is in the same metallogenic geological background conditions and formed by the different nature of the structure, the two deposit types are the mineralization subclass of the one deposit type( "Linglong-jiaojia type" gold deposits).(5)About 120 Ma ago,the lithospheric thinning to peak, it cause the occurrence of large-scale mantle-derived magma and large-scale gold mineralization.Linglong gold deposit is the product of this tectonic activity.Linglong gold deposit is a typical of mesothermal-type deposit.