Discussion On Geological Characteristics,Source Of Ore-forming Materials And Genetic Model Of Shuangwang Gold Deposit,Shaanxi Province

Shaanxi Shuangwang Gold Mine is located in Wangjialeng-Wangjiazhuang area in the southwest of Taibai County,Baoji City,in the southeast of Fengtai ore field in the west Qinling polymetallic metallogenic belt of China.More than 200 gold deposits have been found in the area,among which the Shuangwang and Baguamiao gold deposits are the representative ones.The deposit is located in the breccia body and occurs in the Xinghongpu Formation of the Upper Devonian.This article mainly to deposit geological characteristics as the object,divide the deposit metallogenic period of time,through the fluid inclusions in different stages of the characteristics of fluid physical and chemical characteristics,by analyzing the main metallogenic period of pyrite in situ trace,in situ S isotope test discussed sources of ore-forming materials,ore deposit origin,and try to establish the metallogenic model,made some results of the study are:(1)Based on field exploration,petrographic observation and previous studies,this paper divides the mineralization process of Shuangwang Gold Deposit into three periods: sedimentary and diagenetic period of Devonian strata,pre-mineralization period and mineralization period.According to the different combination and output relationship of minerals,ore-forming for albite phase(phase ?)before the metallogenic period and divides the main ore-forming period and the late ore-forming,including iron dolomite-pyrite metallogenic phase phase(phase ?)-iron,dolomite,calcite and pyrite phase(phase ?),and the period is divided into different stages pyrite Py ? and Py ?,late ore-forming stages including calcite,quartz(? stage)and gypsum-fluorite phase(phase ?).(2)The study of fluid inclusions in the mineralization period of the deposit shows that the fluid of the deposit has the characteristics of medium low temperature,medium low salinity and low density.The ore-forming fluid in the main mineralization stage is mainly magmatic water with the participation of metamorphic water.In the late stage,the magmatic water is mixed with atmospheric water and changes to atmospheric water.(3)In this paper,the pyrite in the main ore-forming period has been tested in situ.The results show that the deposit is a medium-low temperature magmatic-hydrothermal deposit.The ore-forming materials mainly come from deep magma,and the formation is mixed in the process of magma rising.(4)Based on the comprehensive analysis of the ore-bearing strata,breccia body characteristics,surrounding rock alteration,ore-forming fluid characteristics,ore-forming material source and ore-forming depth of Shuangwang gold deposit,this paper compares the characteristics of the domestic cryptoexplosive breccia type gold deposit,and considers that the deposit is cryptoexplosive breccia type gold deposit,and tries to establish a metallogenic model map.