The Geological Characteristics And Enrichment Regularities Of Mineralization Research Of Tugurige Gold Deposit In Urad Zhongqi,inner Mongolia

Tugurige gold deposit in the northwest of Urat Zhongqi which is tectonically located in Baoyintu-Xilinhaote volcanic passive epicontinental zone in terrigenous hyperplasia belt of northern north China plate is a polymetallic metallogenic belt of gold,chrome,copper and iron deposit.This area experienced prophase ancient Asian Ocean subduction-orogenesis and anaphase Permian tectonic setting of splitting extension.The exposed strata in mine area are upper rock of Baoyintu Group of Ancient Proterozoic and Quaternary strata.Magmatic rocks in the region are greatly developed and magmatic rocks related to gold mineralization are early Permian porphyritic granite and middle Permian diorite.Porphyritic granite and diorite are quasi aluminum high potassium calcic alkali according to their geochemical characteristics.Metallogenic epoch of gold following orogenic event is middle Permian.There's no deep fracture but north-west trending secondary fracture in mine area.Quartz filled into secondary fracture to form ore bodies which are completely controlled by structure.There're 69 quartz veins in mine area,14 of them are ore bodies with industrial value.The main ore bodies are 7,2,2-1,2-2,2-3,2-6.They can be divided into two groups according their trending:one trending 117°,the other trending 140°.The mineralization types are quartz vein type and fractured altered rock type.The shallow part is mainly quartz vein type and gradually turn to fractured altered rock type in the deep.The Ore minerals of Tugurige gold deposit are mainly pyrite,chalcopyrite and galena.The gold in the ore is mainly natural gold,most of which are fissure gold and intergranular gold,inclusions gold are few.According to mineral characteristics and the metasomatic dissolution relationship of metal sulfide,the hydrothermal mineralization period of Tugurige gold deposit can be divided into four stages,which are quartzite stage,quartz sulfide stage,gold quartz stage and quartzite calcite stage.The main metallogenic periods are quartz sulfide stage and gold quartz stage.The ore-forming fluid in the western mining area of Tugurige gold deposit with characteristics of middle temperature?260³00??,low salinity?2¹4wt%NaCl?and low density is H₂O-NaCl-CO₂ system rich of H₂O and CO₂.The range of metallogenic pressure is 66¹04MPa,and the range of metallogenic depth is6.56⁸.43km.H and O isotope characteristics are closely to primitive metamorphic water.It suggested that the ore-forming fluid is mainly metamorphic hydrothermal solution which is the same with the fluid of orogenic gold deposits.The range of?³⁴S is-9.0‰^-0.5‰,and mainly distribute in-9.0‰^-5.4‰and-2.9‰^-0.5‰.The value of?³⁴S in general ranges widely,but mainly distribute in two ranges indicate that ore-forming fluid originates from two kinds of fluid,one of which is similar with mantle,the other is similar with sedimentary rocks and metamorphic rocks.Combine with regional geological background and source of ore-forming fluid,it can be conclude that the main sources of the metallogenic material are mantle and ancient metamorphic rock of Baoyintu group.The geological characteristics and ore-forming fluid of Tugurige gold deposit is orogenic gold deposit.The genetic type of Tugurige gold deposit is orogenic gold deposit.It is controlled by structure such as regional fault and secondary fracture.The shape and extending direction of secondary fracture control the shape,extending direction and thickness of ore body.The fault is locally tensioned or extruded result in the trend and tendency of fault changing.Fault is different in wide,in the wide area,ore bearing space is large.Ore veins are slightly wavelike and piecewise enrichment vertically and horizontally.Ore body enrich in where occurrence changes.Orebody thickness and enrichment changes interphase vertically and horizontally.The law of lateral volt is not obvious,but the law of lateral volt of 2-3 ore-body is most obvious.The ore body lies to the side of NWW and has a larger side angle.