Genesis And Geology And Geochemistry Of Copper-Molybdenum Deposit Of Chigou, South Qinling

Chigou area is in the Zhashui basin of the South Qinling lying in only about20km south of the North China plate and Yangtze plate suture line (Shang-Dan fracture), the south side of which is close to the Feng town-Sanyo deep fault,which is active.The studying area, exposes the strata in the Late Devonian-Carboniferous a light deterioration of the marine fine clastic-carbonate rocks, the development of rhythmic layering.To the Chigou region of the newly discovered copper-molybdenum deposit is the object of study, and important drilling carried out systematic sampling autopsy, hot and cold through the microscope, electron microprobe, isotopic dating, and other means to carry out the ore-bearing rock alteration mineral assemblages. the study of fluid inclusions,determining the stage of mineralization,alteration and mineralization characteristics of physical and chemical conditions and material sources, compared with China has the porphyry copper-molybdenum mine, on the basis the type of deposit The following results have been.yielded:The mineralization of the deposit can be divided into three mineralization stages, respectively, for the silicified sulfide of potassium, silicification, chlorite and sulphides and the zeolite sulphide carbonate, the second stage can be seen as the main mineralization stage.1) Quartz inclusions and the composition of the gas and liquid phase analysis showed that the ore-forming fluids is characterized by the rich of CO2, temperature,salinity,temperature and high salinity,CO2-H2O system belonging to the whole, the main mineralization stage of ore-forming fluid temperature is about290℃,the overall salinity to19.22w (NaCleq)%for the peak2) Precise dating of Chigou area rock isotope work, The results showed that:Chigou mine Ⅰ-Ⅵ rock,as well as deep drilling and mineralization is closely related to the rock sticks LA-ICPMS zircon U-Pb age of148±1Ma～140±1Ma, formed in the late Jurassic-Early Cretaceous.3) Proposed Chigou area granite belongs to the I-type granitic rocks of the calc-alkaline series, there are potassic, propylitic rock and quartz sericite alteration and molybdenum mineralization and potassic closely related copper mineralization stages the chlorite epidotization superimposed potassium is closely related.