The Study On Ore Deposit Geological Feature And Metallogenic Prediction Of Yinchang Gold Deposi T In Pingwu County,Sichuan Province

There are 5 main ore bodies in the study area,all controlled by faults.The fault structure controlled the extension and the yield of ore body.The ore body is in the form of fine grain impregnation.It occurs in the interlayer fracture zone of the lower part(T2Z1)of the Triassic midgame brain group and the lower part of the Triassic bozogou group(Tib)contact position.They are laminar,veined and lenticular,and few are irregular.The roof and floor of the ore body are mainly composed of cataclastic feldspar quartz and calcareous limestone and sericite.Ore body length:100?698m;thickness 0.3-13.06m,average 2.45-5.82m;dip angle of 60?65°.Ore grade 1.01?101.48 ×10-6.The deposit is a large gold deposit.The ore types can be divided into sand-slate type and altered limestone type.The main structure of the ore is granular,residual and scaly.The ore structure is mainly pulse structure,disseminated structure and breccia structure.The metal minerals that make up the ore mainly include pyrite,poisonous sand,cinnabar,stibnite,realgar,ore-yellow,natural gold.Non-metallic minerals are mainly quartz,feldspar,calcite.,sericite,carbon,etc.The gold mineral in the ore is fine granular.,the shape is mainly leaf shape,plate shape,irregular shape and round shape.Gold mainly exists in the form of pyrite,arsenopyrite and other sulfide in the form of silicate quartz.The alteration of surrounding rock includes pyrite mineralization,toxic placer mineralization,stibnite mineralization,cinnabar mineralization,realginization,ore-yellow mineralization,etc.Uniform temperature of fluid inclusions in quartz between 120??230?,the average 170?.Combined with the properties of surrounding rock,ore bodies are mostly medium and low temperature hydrothermal alteration,and the ore body is subject to the tectonic mineralization of fault?it is believed the gold deposit belongs to the medium and low temperature hydrothermal deposit formed by multiple stages and later superposition.The pyritein the ore-bearing rock system is analyzed in terms of 6 34S:-10.5‰?+5.1‰(average-2.70‰).,and ? 34S of the sulfide formed during the hydrothermal mineralization period(stibiite,realgar and cinnabar)is-4 ‰?6.5‰,average-5.3 1‰.Ore-forming hydrothermal delta 34 S,S between mantle sulfur and sulfur formation,so it is possible that sulfur in the ore-forming hydrothermal as mixed with sulfur of mantle source and sulfur of stratum.The formation of ore deposits is controlled by fracture tectonics,strata and wall rock alteration.Five prospecting criteria of structure,stratum,alteration of surrounding rock,remote sensing interpretation and geochemical anomaly are obtained,and three prospecting prospective areas are delineated.