Study On Granite And Mineralization Of The Zhuxi W-Cu Deposit,Northeast Of Jiangxi Province

Zhuxi W-Cu deposit is a world-class tungsten deposit which is discovered in recent years.Its formation mechanism has aroused the interesting of many scholars all over the world.With the research work,there are made many great progress in the deposit geological features,regional magmatic rock characteristics and other respects.Due to the complexity of the metallogenesis of Zhuxi W-Cu deposit and the diversity of the magmatic rocks in the mining area,there are still many problems in the study.Sush as the types and evolution sequences of the magmatic rocks,the relationship betwwen mineralization and magmatic rocks,the period of magmatic rocks in Zhuxi mining area,the particularity of the magmatic rocks in Zhuxi mining area.Based on this background,this paper have a study at magmatic rock and mineralization,including petrography and petrogeochemistry,combined with isotopic chronology and isotope geochemistry.Aimd to determine the magmatic evolution sequence of the Zhuxi deposit and its relation with mineralization.From the perspective of magmatic rock,answer the question "why Zhuxi can form such a large-scale tungsten ore?"The main results of this paper are as follows:(1)The study shows that the magmatic rocks associated with mineralization in the Zhuxi mining area are sericite biotite granite,muscovite granite,muscovite granite porphyry and dolomite granite.Among them,sericite biotite granite is mainly related to skarn type mineralization,and dolomite granite is mainly related to meteorite mineralization.(2)The biotite granite,muscovite granite,muscovite granite porphyry and dolomite granite in the Zhuxi mining area are homogeneous magmatic rocks,which belong to the high degree of differentiation,high Si,aluminum,high calcium and alkaline series.Rock mineral characteristics indicate that they belong to S-type granite.(3)The Mesozoic magmatic activity in the Zhuxi mining area and its surrounding area is mainly divided into three phases: the first phase is mainly related to Cu,Mo and W mineralization(about 160Ma);the second phase is mainly related to W mineralization(about 150Ma);the third phase(130Ma)has not been found in this period of magmatic activity related to mineralization.(4)The tectonic setting of the Yanshanian magmatic activity in the Zhuxi mining area is the intracontinental dive caused by the oceanic assemblage.Magmatic activity starts at about 160 Ma,with ?Hf(t)value-5.7~-9.9.To about 150 Ma,compared with a certain mantle material to join,?Hf(t)value of-4.9~-8.9.At 130 Ma,with the addition of mantle material,the ?Hf(t)value is-5~1.5.(5)Compared with other major tungsten in South China,summarizes the uniqueness of magmatic rocks in Zhuxi mining area.