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On The Geology Geochemistry And Genetic Model Study Of The Jiapigou Ore Deposit Of Jilin Province

Posted on:2010-07-07Degree:MasterType:Thesis
Country:ChinaCandidate:H J YuFull Text:PDF
GTID:2230360272988064Subject:Mineralogy, petrology, ore deposits
Abstract/Summary:PDF Full Text Request
Jiapigou gold deposit is located in the Northeast margin of North China Plate, the northern margin of East and West tectonic belt of Tianshan~ Yinshan. the transition zone for Huifa River Chinese-style structure with the composite site of east-west structural zone, Studied in detail on geological background, the characteristics of fluid inclusions, ore-forming and ore-forming events of the era and the granite which is closely related to the ore deposit, the geochemical characteristics of dikes:Jiapigou ore body exist in North West the ductile-brittle shear zone. The surrounding rock of the body is mainly Archean amphibolites and gneiss, Mesozoic granite and Mesozoic dikes. The main ore is quartz vein, a small amount is the altered rock type. Ore minerals are mainly pyrite, chalcopyrite, sphalerite, magnetite, sulphides, etc. The surrounding rock alteration of ore body is sericite and chlorite, and silicides. Mineralization can be divided into four stages: quartz stage, pyrite stage,polymetallic sulfide-quartz stage and quartz-carbonate stage stage; Fluid inclusion homogenization temperature is 143.5℃~ 429.8℃,the main ore-forming temperature is 200℃~ 390℃,belong to the high temperature range. Salinity is 4%-10%, belong to the range of low-salinity. The gas composition of fluid inclusion is CO2, H2O, a small amount of CO,N2,CH4 showing the characteristics of mantle-derived fluid, on the whole is a H2O-CO2system; The analysis to the stable isotope of the ore:δ18O between 9.14‰to 11.99‰,δD‰between -70‰to -93.0‰,δ34Sbetween 3.82‰to10.4‰, an average of 7.323‰, 206Pb/204Pb between 16.03 to 20.99, 207Pb/204Pb between15.21 to 16.21, 208Pb/204Pb between 36.02 to 40.99. Ore-forming fluids come from the mantle-derived magma, a mixture of atmospheric precipitation, minerals mainly come from the mantle, part of the earth’s crust may be a mixture;Testing granite age with Zircon U-Pb method, the dating results show that the time for diagenetic is 166.4±5.1Ma ~ 185±4Ma, having the similar age with the Huangniling granite, with previous measured 177.7Ma; Based on the granite characteristics of shell and mantle-derived source, the dikes characteristics of mantle-derived. The diagenetic mineralization is closely related to the subduction of basaltic oceanic crust dehydration melting, formed by the the mafic magma and a large number of crustal materials, and the dikes may be generated by the mafic magma.Jiapigou gold deposits formed in the Mesozoic. In the Mesozoic, the Izanagi plate subduct into the Jilin Plate, with the calc-alkaline composition of the magma and hydrothermal systems forming, come along the deep fault into the early formation of the ductile shear zone, the ore exist in the ductile shear zone. Jiapigou gold deposits are the Medium temperature、the Medium pressure、hydrothermal、quartz vein-type gold deposit with the relevant to collision orogeny.
Keywords/Search Tags:Jiapigou, Mineral deposits geology, Fluid inclusions, Geochemistry, Genetic model
PDF Full Text Request
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