The Granodiorite Geochemistry Significance And Ore-space Research Of Xianjiaonang Porphyry Copper Tibet

This paper general research on the granodiorite of petrology, geochemistry,characteristics of ore-hosting space and rock formation background aspects inXianjiaonang porphyry copper Tibet. Use fluorescence spectroscopy and ICP-MS asmain methods to geochemical analysis the constant, trace and REE of granodiorite.The deposit formed tectonic setting is determined by the geochemical characteristics.This study found the combination of Xianjiaonang granodiorite rock mineralsare: Quartz+plagioclase+K feldspar and biotite (part of which is formed by thealteration of hornblende), the main accessory minerals are sphene, apatite and avariety of metal mineral. Granodiorite, which with high K and SiO2(>62%),alkali-rich low CaO and TiO2as well as low MgO and paluminous characteristic,belongs to high K peraluminous calc alkaline rock. Major and trace elements researchresults showed that the granodiorite is adakitic rock. The study results suggest that themagma source may be mafic lower crust, which under the collision and extrusionstress cause the crust or rock plate fracture delamination, then stress release causepartial melting magma emplacement along the fissures. The whole process is a seriesof complex geological evolution. The ore-hosting space is developed in granodioriteand filling better, and filling material include chalcopyrite, pyrite ore minerals andgangue componrnts like quartz. The research of granodiorite tectonic background hasshowed that the rock formed in the collision stretching stage, which is prefectlyconsistent with the tectonic setting of Gangdese porphyry metallogenic belt.Under the studies in petrology of granodiorite and geochemical, the results showthat the granodiorite formation in the background of beneficial with typical adakite, isvery favorable for mineralization. In summary, the copper and molybdenum mine instudy area (especially copper mine) has good ore prospecting.