Mineralization Study Of The W-Cu Polymetallic Deposit In Zhuxi,Jiangxi Province

In this paper,the Zhuxi W-Cu polymetallic deposit on the Qinhang metallogenic belt in south china is the resrarch object.By exhaustive studies of deposit,the author analyzed the geochemical character of the granite and porphyry related to mineralization,metallogenic epoch of orebody,and identitfied the charater and origin,determined formation mechanism of the deposit,and study the mineralization of Zhuxi W-Cu polymetallic deposit.Zhuxi W-Cu polymetallic deposit has a typical skarn mineralization,according to the mineral metasomatic relations,and the characteristics of the mineral combination,it can be divided into skarn period,quartz-sulfide period,carbonate period and supergene oxidation period.The tungsten mineralization is mainly developed in the oxidation phase which is in the middle of skarn period and quartz-sulfide period,copper mineralization is mainly developed in the quartz-sulfide period.Temperature measurement of the fluid inclusions show that mineralization temperature of without water skarn phase is 309?334?,salinity is 3.87-5.86%NaCleqv,mineralization temperature of oxidation phase is 174?360 C,salinity is 1.57-5.86 NaCleqv and mineralization temperature of quartz-sulfide period is 160?240?,salinity is 0.88?8.00%NaCleqv.H-O isotopes of quartz show that the fluid and material are both from magma.Meanwhile,and it also indicates that there is a large number of atmospheric precipitation in the fluid,and may lead to the precipitation of sulfides.To study the metallogenic epoch of orebody by zircon U-Pb dating of the granite and porphyry,Ar-Ar dating of alteration muscovite and Re-Os dating of molybdenite.It shows that the mineralization of Zhuxi W-Cu polymetallic deposit appears in about 151Ma,tungsten and copper mineralization is mainly developed in the 149Ma and last to 145Ma.This paper study on the geochemical character of the granite and porphyry related to mineralization,metallogenic epoch of orebody,and identitfied the charater and origin.The results indicated that the mineralization of Zhuxi W-Cu polymetallic deposit is controlled by the anatectic granite,which is the are the result of large-scale lithospheric extension of Mesozoic in southern China.