Jinduicheng Granite Porphyry Molybdenum Deposit Mineralogical And Geochemical Characteristics,shanxi Province

Jinduicheng porphyry molybdenum deposit,as a super-large molybdenum deposit caused the attention of many scholars both at home and abroad,is located in Huaxian county,Shanxi Provoince.The cause and the forming environment of Jinduicheng porphyry granite remain controversies and the mineralogical study of the deposit is some shortage.In this paper,we research on petrology,mineralogy and geochemistry of the granite porphyry by using microscopic,EPMA,Zircon chronology and LA-ICP-MS.The following are major achievements obtained in this dissertation.1.Jinduicheng granite porphyry has porphyritic stucture,flesh red and its phenocryst,granularity between 2.5mm to 5mm,are quartz and K-feldspar.Rock-forming minerals are quartz,K-feldspar,albite,plagioclase,muscovite,biotite.Accessory minerals are apatite,magnetite,ilmenite,calcite,zircon,sphene,monazite,xenotime.2.Jinduicheng granite porphyry that is rich in Si,K and Al,belongs to the silicon supersaturated super-acid Alkaline-calcium series.The rocks have the characteristics of enrichment in LREE and loss in HREE,with slight Eu negative anomalies and the chondrite-normalized REE pattern is right deviation.The characteristic of trace elements is rich in high field strength elements of U,Pb and Th.Zircon U-Pb age of the granite porphyry is 139.44±1.2Ma.Jinduicheng granite porphyry formed in the Yanshanian.3.The deposit can be divided into Potassic zone-Phyllic zone-Silicified zonePropylitization zone from porphyry to surrounding rock.The main alteration minerals include K-feldspar,biotite,muscovite,quartz,chlorite,epidote and calcite.4.The metallogenic period of this deposit can be divided into three periods: gas metallogenic period,hydrothermal mineralization period,the surface metallogenic period.Among them,the hydrothermal mineralization period has three stages: the first stage is K-feldspar-sulfide,the second stage is quartz-sulfide and the third stage is quartz,quartz-calcite.5.The metal minerals of Jinduicheng porphyry molybdenum deposit mainly include magnetite,pyrite,chalcopyrite,molybdenite,sphalerite,galena,hessite,aikinite,schirmerite,Bi-and Ag-bearing galena.6.Jinduicheng granite porphyry material sources mainly come from the crust,formed in the transition of south-north extrusion stress turn to east-west tensile stress.7.The ore-forming temperature of the deposit is medium temperature.The ore-forming material sources come from the lower crust and mixed with a few mantle source material.