Metallogenic Regularity And Mineral Potential Evaluation Of Cu In Northeastern Junggar,Xinjiang

Northeastern Junggar is one of the most important copper metallogenic belts in Xinjiang,with many copper deposits discovered in the area.In recent years,with increased exploration,the difficulties for new discoveries grow significantly,the prospecting work is facing many new challenges,with the most important and urgent challenge is the direction and guidelines for the future prospecting and mineral exploration.This paper summarized the results from previous researches,the studies on signatures of copper metallogenic and the assessment on the potential of copper mineralization.The key progress and understanding are listed as follows:1.There are five sub-types of copper mineralization in the study area,including the mineralization related to mafic-ultramafic rocks,porphyry type,skam type,skarn storey reconstruction of volcanic rocks and volcanic hydrothermal types.2.The LA-ICP-MS U-Pb dating study on zircon collected from the intrusive rocks at Yulekenhalasu copper mine indicates the five major magma-volcanic activities in the areas,dated at 382Ma,379Ma,375?374Ma,348Ma,266Ma Nine molybdenite samples have Re-Os Isochron age of 373.9±2.2 Ma,indicating that copper-molybdenum mineralization was occurred in the late of Middle Devonian,most likely related to diorite porphyrite intrusion.3.The La-ICP-MS U-Pb dating study on zircon collected from diorite porphyritic Qiaoxiahala Fe-Cu-Au deposit has the date of 377.6 ± 1.4 Ma.The Re-Os Isochron age study on 4 molybdenite samples collected from the ore has age of 377.4 ± 4.3 Ma,in consistence withthe age of diorite porphyrite,indicating that of Cu-Au deposit was skarn-type related to related diorite porphyrite intrusive in the late of Middle.Devonian.4.Geologically,the Suoerkuduke Cu-Mo deposit is a skam-type mineralization,with Re-Os Isochron dating study on 2 molybdenite samples have isotopic model ages of(290.3.6 ±4.3)?(293.5 ± 4.5)Ma indicating that deposit was formed in the first phase of Early Permian.5.Studied the Yulekenhalasu copper deposit,Qiaoxiahala iron-copper-gold deposit,Suoerkuduke copper and molybdenum deposit and the Kalatongke copper-nickel mine,and established the metallogenic model and prospecting model for these deposits.6.Based on current study combining with historic geochronological data,the copper mineralization in Northeastern part of Junggar can be divided into four phases,including the Middle Devonian(374?380Ma),the early Carboniferous(327?333Ma),in the end of the Late Carboniferous-Middle Permian(265?305Ma)and late Triassic-early Jurassic(198?230Ma).7.The study on Re in the molybdenite shows:Yulekenhalasu of porphyry-type ore deposits have features of mantle origin of the ore forming materials,with the superposition of Qiaoxiahala skarn-type Cu-Au deposit and Suoerkuduke of skarn-type copper-molybdenum deposit have the ore-forming material from the mantle.8.Metallogenic series of copper deposits in the study area can be divided into four sub-series.Established the potential assessment model for the deposits related to mafic-ultramafic.intrusive,porphyry-skam.type and regional forecasting models of the marine volcanic type of copper deposit,and optimization of 13 prospecting targets in category A and B.Provided recommendations on the exploration techniques and strategically exploration programs for the studied area,and provided assessment on the ore-prospecting potentials for each genetic type of deposits.