Relationship Between Carboniferous-triassic Tectonic-magmatic Evolution And Mineralization In The Eastern Tianshan Area

To a certain extent,the understanding of the relationship between Carboniferous-Triassic structure-magmatic evolution and metallogenesis in East Tianshan lacks systematic and comprehensive research methods and relatively unified comprehensive conclusions.This paper systematically collects and organizes the published zircon U-Pb single-point age big data and 7 types of main minerals' spatio-temporal structure laws from the perspective of the theory of permeable magmatic fluid mineralization,and summarizes the main structures-Magmatic evolution sequence,metallogenic regularity,mechanism of tectonic-magmatic evolution and fluid coupling mineralization,and discussed the geodynamic mechanism.The Aqishan Pb-Zn(Cu)deposit is representative of the Carboniferous-Triassic tectonic-magmatic evolution sequence and metallogenic characteristics of the East Tianshan,but its genesis and ore-controlling factors are still weakly studied.Geology,Xiaodongshan volcanic mechanism rock combination,tectonic ore control,fluid migration characteristics and chronology.The problems of ore-prospect difficulties and slow in surface prospect in China are prominent.The innovation of prospect theory is one of the ways to solve this problem.The major innovative ideas can be drawn as follows:(1)East Tianshan experienced the Late Ordovician-Early Devonian(subduction)?Early Carboniferous(collision+Junggar secondary mantle plume?)?Late Carboniferous(slab fragmentation-lithospheric delamination+Junggar secondary plume?)?Early-Middle Permian(Tarim secondary mantle plume)?Late Permian-Early Middle Triassic(intraplate evolution)geodynamic mechanism.(2)The main mineralization period of most minerals in East Tianshan is in the intermittent period of Carboniferous-Triassic structure-magmatic activity,Coupled with a large number of fluids,has the characteristics of metallogenesis after the magmatic period.Early Carboniferous porphyry copper deposits,volcanic iron deposits,late Permian-Early Triassic ductile shear zone type gold deposits,and early-Middle Triassic porphyry molybdenum-tungsten deposits related to plate structure are plate melting Metallogenic system of permeable magma fluid generated,product of coupling or decoupling of melt and fluid;upward migration of deep ore-bearing fluid triggered by slab detachment-lithosphere delamination and late Carboniferous volcanic copper polymetallic deposit,Volcano-subvolcanic hydrothermal copper polymetallic deposits,Early Permian volcanic iron deposits,volcanic hydrothermal or volcanic silver polymetallic deposits are closely related;Tarim Permian mantle plume is related to Early-Middle Permian Late basic-ultrabasic rock-nickel copper-nickel deposits have a genetic relationship.(3)The metallogenic process of the Aqishan Pb-Zn(Cu)deposit is divided into early silicate hydrothermal fluids and late carbonate fluid metallogenic stages.The main contribution of granite porphyry to mineralization: the early skarnization zone formed by the decoupling of the rock body and its magmatic metallogenic system to the ore-bearing fluid related to the Xiaodongshan volcanic mechanism in the later period,Only part of the heat and minerals are provided.The ore-bearing fluids related to sub-volcanic rocks such as syenite porphyry are divergently produced in non-synchronized layers and at high angles in fractures,fracture zones and rock micro-fissures.Ore body.The main metallogenic period is restricted to 292.0?320.0±1.6 Ma.The ore-forming fluid has low temperature-medium salinity.The sulfur isotope has the characteristics of mantle source and volcanic hydrothermal fluid.The main mechanism is the demolition of the lithosphere.(4)The filling and metasomatism of ore-bearing volcanic fluids is the main metallogenesis,because of the volcanic hydrothermal Pb-Zn(Cu)deposits,and the establishment of metallogenic models.Aiming at the current problems of prospecting difficulties and slow prospecting under the objective conditions of prospecting and prospecting in my country,the meso-level "Hot Rock-Branch prospect theory" is timely proposed,and the process of discover new deposits by using this theory is expounded.