Space-Time Framework Of Structure-Magma-Mineralization Of Alkali-Rich Porphyry Mo-Cu-Au Polymetallic Deposit In Boxingchang, Yunnan Province

Baoxingchang Mo-Cu-Au polymetallic deposit located in the triangle land which surrounded by SW of fold in Lijiang platform edge,NW of deep-big fault of Jinshajiang-Ailaoshan and NNE of deep-big fault.Jinshajiang-Ailaoshan orogenic belt was an intracontinental orogenic belt which grew under marginal rift of passive continent.From early Eocene to later Oligocene epoch,a series of right-lateral strike slip fault formed by convergence and collision of Indian-Eurasian continent,and jostle in North,Thereafter EW strong compressional stress component formed by Indian continent wedging fiercely,and colliding with Yangtze continent in NE,Up to later Oligocene epoch,North part of Jinshajiang-Ailaoshan fault(North of Deqin) was SN left-slip,and formed bounding fault zone of East Yangtze landmass and West Qiangtang massif.Along the slip fault zone grew alkali-rich intrusive rock and kali lava in Cenozoic era,where Machangqing rock body of Baoxingchang deposit located in.Based on the former theories;directed by metallogenic system;used lithology,tectonics, study of mineral deposit,trace and time by radioactive isotope,major and micro lanthanon, stable isotope and fluid inclusion as the methods to do the research.The paper reveals that diagenetic environment of Machangqing rock body in Boxingchang deposit was continental arc environment of continental margin after collision. Diagenetic mineral rooted in rich mantle and lower crust,2～10%of lower crust that thickened caused by delamination of lithosphere in lower crust or subface erosion of magma in mantle was partial fusion,fractional crystal degree is 0.6,contamination ratio is 0.2,in extension environment;magmatic intrusive age is from 23.18 to 55.49Ma;rock body is alkali-rich porphyry with the character of adakite;it builds the space-time structure model of tectonics-magma-mineralization of the deposit,and discussed the metallogenic series of Mo-Cu-Au-Pb-Zn.Mo-Cu ore was high-medium temperature magmatic hydrothermal deposit;Cu-Au was medium temperature magmatic hydrothermal deposit;Au-Pb-Zn was medium-low temperature hydrothermal deposit,There were 3 types of mineralization: porphyry-type Mo-Cu deposit,contact belt Mo-Cu-Au deposit,fault zone(fracture altered rock) Cu-Au-Pb-Zn-Ag deposit;they all belonged to the same mineralizing fluid and mineralization,but in different mineralizing phases,all of which formed whole evolution series,temperature and pressure from high to low;it also predicted 6 prospecting areas by using model of diagenetic and mineralized dynamic mechanism.