| The discriminating of the tectonic setting and geochemical anomalies in East Kunlun considers that,porphyry copper deposits should be an important copper resources in this area.Through the study of the petrology geochemistry and geochronology about the typical porphyry rocks,and the study of stable isotopes,fluid inclusions,and mineralization chronology about the porphyry deposits in theeast of East Kunlun,we discuss deposit genesis and mineralization characteristics of porphyry deposits to summarize metallogenic regularities of porphyry deposits in the region,mainly achieved are conculed as follow:1,The granodiorite porphyry in Harizha mine is peraluminous,high-K calc-alkaline to shoshonitic rock series.The charactersistic of REE is showed as high fractionation about the LREE,compared to HREE,significant losses about the Eu anomaly,represents the mix of crust-mantle,and Adakitic characteristics.The zircon U-Pb ages of granodiorite porphyry is 233.6±4.3Ma,representing the rock formed in the Triassic.Its tectonic discrimination shows that the granodiorite porphyry formed in the same collision tectonic environment.Fluid origin of the pyrite proved to be magma mainly influenced by wall rock,H-O isotopes indicates the metallogenic fluid is magmatic water mainly and affected by atmospheric precipitation.The zircon fission track ages of granodiorite porphyry in the mine concentrated in the 130-150Ma and 180-210Ma,mineral zircon fission ages focused on 90-120Ma,140Ma and 210Ma,with ore fission track ages of times corresponding with the zircon fission track ages of granodiorite porphyry,also showed the relationship between granodiorite porphyry and mineralization.2,The dioritic porphyrite in Wulonggou mine is typical metaluminous calc-alkaline rocks,the REE shows as LREE enrichment,negative Eu anomaly being not obvious,?REE low;characterized by loss of trace elements Nb,Ti,P and enrichment of Rb,Ba,Th,U,La,appears trace element characteristics as typical I-type granites,in the Na2O-K2O diagram,I-type granite falls area,belong to a continental collision environment.Its invasion age is 220.3±1.3Ma,related to the lithospheric delamination caused by underplating related in East Kunlun area.?34S values of pyrite in the mining area mainly range from-1.44 to 11.03 ‰,mean of 3.81 ‰,display the characteristic of magmatic sulfur source;.H-O isotopes indicates that ore-forming fluid inside the mine is magma water-based,and latter affected by atmospheric precipitation;lead source of minerals and ores mainly from the orogenic belt,including the crust ingredients,lead source of rock minerals and ores are similar,mainly from the orogenic belt,also includes the crust ingredients,indicating mineralization,magmatism and orogeny's correlation.Wulonggou gold deposit exists Caledonian mineralization and the main mineralization stage include diorite intrusive age about 220Ma and zircon fission track ages 160Ma and 96Ma around.3,Jiadanggen deposit is formed by intrusive porphyry ore in Late Triassic.Copper thermal fluid,except the enrichment of porphyry mineralization inside,also flows along with broken space of the wall rock to enrichment.The porphyrys in Dongshan copper mineralization points are peraluminous,high-K calc-alkaline porphyry intrusive age was 248.4±1.8Ma,zircon fission track ages are 125Ma and 159Ma.4,The mineralization porphyry in the eastern East Kunlong are mainly acidic porphyry(sticks)of Indo-Yanshan super shallow phase and geochemical characteristics show of the performance of Adakite related,calc-alkaline-hign K calc-alkaline,crust-mantle mixed source controlled by deep faults;the wall rock of porphyry are Paleoproterozoic metamorphic rocks and Triassic elashan tuffaceous mafic volcanic rocks and lava;copper ore body mainly formed in the outer parts of the porphyry's exhumation or in contact zone with the ore-bearing porphyry,the scale of the ore body is small,irregular shape.Mineralization and alteration zonation is not obvious,the main is propylitization,partially porphyry branches is silicified or phylitization.The porphyry deposits presence three mineralization age in the region,mainly from the late Triassic to late Yanshanian. |
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