Genesis Of Diorite Porphyrite In Oubaragu Copper-gold Deposit,Inner Mongolia And Its Significance To Mineralization

The Ou Bragg copper-gold deposit is located in Bayannaoer City,Inner Mongolia.The tectonic location is located in the western part of the northern margin of the North China Plate and the eastern margin of the Alxa Micro-Continent.Metallic minerals such as copper and gold are rich in resources.Diorite porphyry and quartz porphyry veins in the mining area are very close to the age of the ore body.It is speculated that the intermediate-acid diorite porphyrite is closely related to mineralization.However,the current degree of research on diorite porphyrite is relatively low.This paper analyzes the petrology,mineralogy and geochemical characteristics of the diorite porphyrite to discuss the genesis of the diorite porphyrite in the European mining area and its significance for mineralization.(1)Diorite porphyrite Si O₂content is 58.87%?65.43%,K₂O+Na₂O content is 4.21%?6.73%,Mg O content is 1.99%?3.40%.Mg^#is 44.28?56.41.The characteristics of trace elements and rare earth elements are also relatively consistent,enriching large ion lithophile elements such as K,Ba,Sr,and Pb,and depleting high field strength elements such as Ni,Ta,and Ti.(2)Diorite porphyrite has experienced complicated magma mixing during its formation.Unbalanced minerals or mineral assemblages such as abnormal plagioclase zoning structure,quartz porphyrite edging structure,massive hornblende,acicular apatite,and plagioclase matrix thickness changes,all suggest magma mixing.happened.(3)The process of multiple magma chambers inverted by the hornblende Thermometer in the diorite porphyrite of the Ou Bragg copper-gold deposit is inferred as follows:8?11 km deep magma chamber crystallizes part of amphibole phenocryst cores;5?7 km central part The magma chamber crystallizes amphibole phenocryst mantle;the 2?4 km mixed magma chamber crystallizes the modified amphibole phenocryst edge;the magma chamber is located 1?2 km to form the matrix amphibole and quartz amphibole Edge,hornblende clumps.(4)Diorite porphyry mineralization in the European mining area is mainly caused by the combined action of fluid overpressure and tectonic stress to cause rock rupture,and then release pressure by fluids rich in Si,Na,K,Fe,Ti and other elements to cause fluid mixing reactions and fluids Phase separation and precipitation and mineralization.The fluid crystal mineral combination is barite+sphene+feldspar+albite+ilmenite+apatite+chlorite+epidote;hematite+pyrite+pyrolusite+tropocite+potash feldspar+calcite+rutile+chlorite+epidote,etc.