The Genesis And Metallogenic Mechanism Of Suoerkuduke Cu-Mo Deposit In The Northern Margin Of Eastern Junggar,Xinjiang

The ore deposit types in the northern region of East Junggar in Xinjiang are extremely abundant and have great metallogenic potential.The Suoerkuduke Cu-Mo deposit is located in the northern margin of Junggar,Xinjiang,and it is located in the Sawuer Late Paleozoic island arc belt in the active continental margin of the northern margin of Junggar.The research of Suoerkuduke Cu-Mo deposit provides reference and scientific basis for geological prospecting work in eastern Junggar region.On the basis of comprehensive field survey and combined with electron microprobe test,the geological characteristics of Suoerkuduke Cu-Mo deposit are observed and analyzed.Systematic study of fluid inclusions.Through isotope geochemistry and chronological research,and the age of rock-forming and ore-forming age is determined.Finally,the genesis and metallogenic model of the deposit are discussed and the following conclusions are obtained:(1)Ore bodies are mainly distributed in the central part of the Suoerkuduke mining area and hosted in the second sub-group of the Beitashan Formation in the Middle Devonian.The mineralization of the deposit can be divided into skarn stage and epigenetic stage.The skarn stage can be divided into three mineralization stages:early skarn stage,degradation alteration stage and quartz sulfide stage.(2)The mineral chemical composition shows that the endmember component of garnet are mainly calcium alluminum garnet,containing a small amount of water calcium alluminum garnet.(3)The H and O contents of garnet and quartz were determined and their isotopic compositions were analyzed.The variation range of garnet ¹⁸O_V-SMOW(‰)in Sorkuduke Cu-Mo deposit is 3.7 to 4.1(‰).¹⁸O_V-SMOW(‰)of quartz varies from 8.5 to 12(‰).On the?D-?¹⁸O_H2Odiagram,the projection point falls between magmatic water and atmospheric water,indicating that the ore-forming fluid of the Suoerkuduke Cu-Mo deposit is mainly magmatic water in the early stage,and later is accompanied by the mixing of atmospheric water.(4)By measuring the C and O isotopic compositions of seven ores,the variation range of?¹⁸C_V-SMOW(‰)is between-1.5(‰)and-7.3(‰),which is close to the variation range of magmatic carbon.At the same time,the?¹⁸C_V-PDB-?¹⁸O_V-SMOWdiagram reflects the magma source of the fluid and is affected by atmospheric water and other factors.(5)The results of sulfur isotope composition in sulfides show that the sulfur isotope composition in the Suoerkuduke Cu-Mo deposit has a certain tower distribution characteristics,and shifts to the positive direction,with a narrow range of variation,indicating that the sulfur isotope composition is relatively stable.It shows that it is a single source with mantle source flow characteristics,and reflects that the ore-forming fluid may be subjected to high temperature,so that the sulfur isotope is highly uniform.(6)The object of chronology test selects the intrusive rocks in the mining area.The skarn ore bodies is transcue by dacite porphyry and granite porphyry.At the same time,Pyritization and Cu-Mo mineralization developed in diorite and syenite granite.The dikes also developed sericitization and clay alteration,indicating that they were closely related to mineralization.Zircon LA-ICP-MS U-Pb dating of the exposed dacite porphyry,granite porphyry and diorite,the result shows that:The ²⁰⁶Pb/²³⁸U weighted average age of dacite porphyry is 371.7±2.3 Ma(MSDW=0.72),The ²⁰⁶Pb/²³⁸U age of granite porphyry is 392.9±5.2 Ma(MSDW=2.1),The ²⁰⁶Pb/²³⁸U age of diorite is 398.4±1.5Ma(MSDW=2.1),Combined with previous metallogenic age data,it is shown that the metallogenic age of the Suoerkuduke Cu-Mo deposit is the end of Middle Devonian.The formation of the deposit is genetically related to the dacite porphyry.(7)Based on the analysis and research of metallogenic background and geological characteristics of the deposit and isotopic composition analysis,the source of ore-forming materials of the deposit is discussed and it is considered that the formation of the mining area is related to the dacite porphyry in this area.The source of ore-forming fluid comes from magmatic fluid and atmospheric precipitation of crust-mantle interaction.The genesis of the deposit is skarn type.