The Magma Evolution And Mineralization Of Huangjinping Gold Deposit,Western Sichuan Province

Huangjinping gold deposit,a larger deposit in Kangding Dadu River gold field,is located in the combination of Yangzi platform and Songpan-Ganzi block and has a long mining history.But as a limitation of the previous research methods and tests,the whole has a low level of study.This work engage in geological background,magmatic evolution regularity,characteristics of fluid inclusions,ore controlling structure,the characteristics of geology and geochemistry of granites and dikes that are closely related to mineralization events of the Huangjinping gold deposit.The magmatic rocks are mainly diorite,granite and granodiorite,as well as fine grained diorite dyke,granitic porphyry and so on.The magma evolution produced a high differentiation degree.The magmatic rock are generally rich in large ion lithophile elements(LILE),lower in high strength elements(HFSE).The distribution pattern of the rare earth elements tends to the right shape showing clear fractionating of LREE and HREE.Eu abnormality is obvious and the diorite and granite have positive and negative anomaly correspondingly.A weak Ce negative abnormality is popular in all magmatic rocks.On the whole the magmatic rocks have very similar distribution patterns for REE and trace element,and the magmatic rock originated from the same magmatic source.Magma evolution from intermediate to acid and from Iitype to S-type.All kinds of granites were separately formed in pre-,syn-and post-collision of plates and belong to orogenic granite.Quartz fluid inclusion results indicate that Huangjinping gold deposit has homogenization temperature of 80?160°,salinities value of 18?22%and average fluid density of 1.07 g/cm3,generally belonging to the high salinity,low density fluid.Based on hydrogen,oxygen,sulfur and lead isotopic characteristics,mineralization fluid in Huangjinping deposit mainly derived from magmatic water,including mantle water and stratum water.Mineralization materials are mainly derived from the deep source mantle,and partly from basic volcanic rocks of the Kangding complex.Huangjinping gold deposit was controlled by the NNE fault,locally controlled by NE and NNE ductile shear zones,and small fractures.Fault-fold structures controled the main ore body distribution.Meanwhile,the ore deposit genesis type is considered as quartz vein-structural altered rock type.There were multiple stages of mineralization,in which the main mineralization concentrated in Himalaya period.