The Contrast Of Geological Characteristics Of Xiasai And Shaxi Silver Polymetallic Ore Deposit In The West Area Of Sichuan

Xiasai Ag-Pb-Zn deposit and Shaxi Ag-Pb-Zn deposit are located in thesouthwest of the Sanjiang,which is in the north of the Yidun island arc fold belt ofsolitary belt.Sanjiang (Nu River, Lancang River, Jinsha River) area in the Southwestof China,which is located in the eastern Qinghai-Tibet Plateau, is a part of the Alps-Himalaya orogenic belt.The tectonic of this area is in the position of the Eurasianplate and India plate,which in the eastern part of the Tethyan tectonic domain, and thedirection is from NNW to SN.The activity of tectonic magmatic is frequent andintense in this area. Metallogenic conditions is very well.The special evolutionaryhistory and strong tectonic magmatic activities create very favorable metallogenicgeological condition.It makes this area become the important nonferrous and preciousmetal ore district,which like gold, silver, copper, lead, zinc, tin and other advantagepotential mineral resources.Each deposit like people’s fingerprints are different(P.B.Barton,1990).Theanalogy theory of mineral prospecting and exploration points out that the similargeological environment and metallogenic conditions can form similar deposit.Andthey have the same resources roughly, but there are some differences in details.Analogy method can be applied to the area that has the same geological conditions tostudy the geological background of the ore forming,the metallogenic regularity oftime and space,the source of regular deposit mineral, the paragenesis of deposit andthe model of ore genesis.Then we can use these to guide the prospecting work.In this paper, the research object is the deposit of Xiasai Ag-Pb-Zn and ShaxiAg-Pb-Zn.It compares the two deposits through the two ore deposit geology,geological features, ore deposit geochemistry and ore genesis exposition. It is thesame that the time and type of two mine magmatite,which occurs in the Sanjiangregion of Southwest Yidun island arc belt,through the comparative study of thegeological characteristics of two mining area.Xiasai lead-zinc-silver polymetallic deposit is located in Yidun island-arcorogenic belt the late Yanshan Rongyicuo granite contact in vitro with low-grade metamorphic is a very large epithermal vein-type silver-lead-zinc polymetallicdeposit.The Deposit is located in the "Sanjiang" Yidun island arc with the westernmiddle of Changduokuo-Hagala tectonic magmatic belt and silver tin polymetallicmetallogenic belt in western Sichuan Province the Batang Yidun Haizi Mountain, thenorth side, as a rich polymetallic deposit containing silver, lead and zinc.The ShaxiAg-Pb-Zn beds in Yidun ancient island arc collision orogen middle Genyen themiddle of the granite belt, the velvet in accordance with the measures on thenorth sideof the rock mass at2-4km. The deposit is located in Changduokuo-Genietectonicmagmatic rocks with northern section Zhangde (secondary) the duplex overturnedanticline paraxial, the general trend of the main fault structure NNW consistent withthe regional structures, strict control of the ore body and the distribution ofmineralization, ore body in the Zhangde the anticline axis along the layer fracturezone. Through the comparative research of two deposits characteristics ofmacro-elementsfluid inclusion characteristics,oxygencarbon isotope,sulfur isotope.Lead isotope,the author considers that Xiasai deposit and Shaxi deposit haveclose locations, both located in the the Triassic Tumugou group. The two deposits andRongyicuo granite are closely related to each other.The inclusion characteristics ofXiasai deposit are same as the inclusion characteristics of Shaxi deposit; Theoxyhydrogen isotope of the two deposits is similar；The sulfur isotope of two depositsis similar,which reflects deep source sulfur characteristic.This paper analyzes Xiasai and Shaxi silver lead-zinc deposit on mineralizationgeological background, geological characteristics, ore geochemistry, mineral materialsources and mineralization model systematicly, and explores the occurrence of thedeposit area rocks, magmatic rocks and mineralization relationships, revealing amineral deposit sources and formation process, as well as polymetallic mineralizationrules. All these studies lead to in-depth study of the genesis of the deposit to providenew information,further guide and promote this type silver prospecting, explorationprofoundly in Yidun area.