The Analysis Aboutthe Geological Characteristics Of Rongna Copper-Gold Deposit,Tibet

Rongna copper-golddeposit is located in the southern margin of the Qiangtang –Sanjiang composite plates,north side of the Bangong co-Nujiang suture zone.It belongs to the Duolong ore concentration area,which is in the Bangong co-nujiang mining belt.The main geology elementsin the deposit are Sewa group of the middle-lower Jurassic of which the lithologyis feldspathic quartz sandstone,Meiriqie group ofthe lower Cretaceous of which the lithology is andesite,Kangtuo group of the Paleogene Oligocene of which the lithology is glutenite,intermediate-acidic intrusive rocks of which the lithology is granodiorite-porphyry,and a small amount of cryptoexplosive breccias.There is a lot of fractures in the feldspathic quartz sandstone and granodiorite-porphyryand these two kinds of rock have obvious mineralization phenomenon.The ore minerals are mainly chalcopyrite and pyrite,tetrahedrite et al,most of which are sulfideare sulfosalt.According to the latest detailed geological records in 2013,combined with the basic analysis data of the samples,The author analyze the relation between the various elements of the geological characteristics and the different elements within the scope of mining engineering controls,obtain the following understanding:In the deposit,porphyry near EW,steep south,the main parts site is located in the middle of the mine-the South East area,emplacement direction roughly south east-North West.The shallow rock occurred bifurcation,mostly columnar or vein emplacement,there is more than one channel of magma emplacement in the deposit;Its intrusion into sewa group of the middle-lower Jurassic feldspathic quartz sandstone and Meiriqie group of the lower Cretaceous andesite,and the formation time later than andesite in the region;Orebody boundary determine by the cut-off grade,overall shape like a funnel,thethickest part is located in Central-South East area of the mine,north and west sides of significantly thinner.Mineralizecontinuity and the average grade forCu is significantly lower.It is indicate that Center mineralized area in the South East,and north and west edges belong mineralization;The relatively high average grade of Cunear the zone where is porphyry and feldspar quartz sandstone contact,indicating the level of minerals gathered with relatively high near the contact zone;In the deposit,the main ore-bearing rocks is sewa group of the middle-lower Jurassic feldspathic quartz sandstone and granodiorite-porphyry,and a small amount of andesite and cryptoexplosive breccias which contact with granodiorite-porphyry contain ore also,the source of minerals have a closely relation with intermediate-acidic intrusive rocksThere is a lot of fractures in the feldspathic quartz sandstone and granodiorite-porphyry,it is the main place ore fluid migration and precipitation,mostly mineralize veinlets filling in fissures,or disseminated-sparsely disseminated,star-shaped distribution.the source of minerals have a closely relation with intermediate-acidic intrusive rocks...