Metallogenic Characteristic Study Of The Halasu Porphyry Copper Deposit In The Eastern Part Of Southern Altay, Xinjiang

The Halasu porphyry copper is located in eastern the Aertai southern margin, Qinghe county ,Xinjiang,The geotectonic position is in the contact region of Siberia plate and the Kazakhstan - Zungar plate, the geologic structure is complex, the magmatic activity is frequent, the mineral resource is rich. At present ,this ore deposit is the first one which most has the prospecting potential porphyry copper ore deposit in the Kalaxiange porphyry copper belt of the ancient Asia porphyry copper (structure) mineralization region, also is the significant breakthrough on porphyry ore deposit investigation in this ore belt.This research work mainly aims at the Halasu porphyry copper mineralization geologic setting, the ore deposit geological feature, the geochemistry characteristic, diagenesis and mineralization chronology, and discusses its material origin and the mineralization mechanism and so on. Through"the porphyry copper deposit mineralization characteristic research, eastern area on southern margin of Altay in Xinjiang" ,it has made following several aspect main progress:1,This article has defined late Paleozoic Era regional tectonic setting and mineralization environment through analyzing the regional geology research results of the southern margin of Altay , strata characteristic, tectogenesis, magma event and so on. This ore deposit take Middle Devonian special rift valley on southern margin of Altay as background. The mineralization occurs in granodiorite porphyry, quartz diorite porphyry and nearby wall rock which intrude the Middle Devonian basalt.2,The mining area including the ore porphyry mainly for the granite diorite porphyry and the quartz diorite porphyry, has belonged to aluminous high-potassium calc-alkaline series. The rare earth, the trace element characteristic demonstrated the ore porphyry originated from the homologous depth portion material in the porphyry time and the hydrothermal stage and had external crust source element.3,This ore deposit mineralization has the multi-stage superimposition characteristic. It appears the potassium feldspar, the biotitize, the propylite as well as the lumpy/vein potassium,silicification alterations and so on which superimposed in the above from the rock mass to the basalt; it can simultaneously see vein-disseminated porphyry type and lumpy/vein hydrothermal solution type in the ore ,also the latter superimposes to the former above. The mineralization may divide into the porphyry time, the hydrothermal stage and the hypergenesis time.4,The Halasu porphyry copper mineralizing fluid is from the mixture of the magmatic water and the meteoric water which composes the hydrothermal circulation system together, in the early mineralization stage mineralizing fluid takes magmatic water as primary, later period is meteoric water. The mineralization has the Multi-stages, the early mineralization temperature is higher than the later period mineralization temperature. Along with mineralization, the mineralization material precipitation and the later period low salinity meteoric water mixed with the subsurface water, the mineralizating fluid temperature, the salinity assumes the degression tendency. The sulfur, the lead, the strontium isotopic content demonstrate mineralization material is mainly from crust material joined in the mantle.5,The Halasu porphyry copper ore deposit metallogenetic epoch should be the Middle Devonian later period (376.9±2.2Ma).The mining area has two diagenesis mineralization event at least,such as Hercynian (375.2±8.7Ma) and Indo-Chinese epoch (217.9±4.2Ma), in Hercynian it formed the disseminated and the stringer vein disseminated whole-rock mineralization body; in the Indo-Chinese epoch, the magma and the fluid activity occurred has superimposed the mineralization once again because of the tectonic thermal event, formed the copper high-grade ore body.6,It initially obtained the Halasu porphyry copper deposit mineralization process for Hercynian porphyry mineralization superimposed Indo-Chinese epoch tectonic-fluid mineralization process,Described"the steamed bun was cut by a knife on upside", realized the copper deposit prospecting direction. Based on mineralization characteristic, combined production, study with research , Project group cooperate with Xinjiang fourth geological team, has arranged the drilling project, has discovered the deep and big ore body in northwest of Halasu mining area. Yuleken Halas in northwest of mining area become significant prospecting region.