Study On The Geochemical Characteristics And Genesis Of The Hede Tungsten Tin Polymetallic Deposit In Sichuan

Since twenty-first Century,the rapid development of economy in China,the metal mineral,especially increase the demand of nonferrous metals,Sichuan Kangding area is China important polymetallic metallogenic belt,the special tectonic position,is located in Songpan-Ganzi geosyncline and the SW margin of Yangtze platform west of the binding site the tectonic position.Due to the complex location in different tectonic zones,the mining area is complex in structure,folds,faults,joints and so on.The NNW compression structure is most obvious,and there are cross twist faults and NE trending fractures.The multiphase magmatic activity in the region has brought rich source and heat source for this area,which lays a good foundation for the migration and enrichment of mineral forming in the region.With its unique geochemical characteristics and metallogenic background,we can strengthen the understanding of the intraplate orogeny and the genesis of tungsten tin deposits,which is of far-reaching significance for ore prospecting and resource evaluation in this area.This paper takes Hede tungsten tin deposit as the research object,using the analysis method of the geological features,Hede tungsten tin deposit and geochemical characteristics and genesis analysis of field geological survey and laboratory samples,and through the Hede tungsten tin deposit in Southern China and polymetallic deposit in comparison.The main achievements are as follows:(1)The shell source granite body and the rock veins control the metallogenesis and form a pulse type tungsten tin ore.The vein is produced on the edge of the granite body or on the upper part of the hidden rock body,and is the same as the quartz vein black tungsten deposit in South China.The mineralization is closely related to the transformation of granite intrusive bodies in the shell source.The ore body is mostly produced in the internal and external contact zone of the rock body.On the whole,the fracture is quite developed,controlling the adult and distribution of minerals,forming a curved multi-metal mineral belt,which plays a favorable role in metallogenic formation.(2)According to the geochemical characteristics of the deposit,it is known thatthe type A granite related to the metallogenic rock mass of the tungsten tin ore in the research area is a type A granite.In the comparison of the metallogenic mineral and petrochemical characteristics,In the research area,there are similarities between ore bearing granites and most of those in southern China during the Yanshan period.The total amount of rare earth samples in each rock sample is different,but the distribution model is generally similar.The rare earth distribution curve is a regular "V" Valley with a smooth tilt to the right,indicating that they are the products of the evolution of homologous magma.The metallogenic rock mass originates from the shallow part of the crust;The average temperature change of fluid inclusions ranges from 130 to 341? and is concentrated between 180 and 240?,indicating that the ore-forming fluid is in a medium high temperature and medium deep environment;Through the determination of hydrogen and oxygen isotopes,it is shown that the water in hydrothermal fluid is mainly magmatic water.(3)The result of Re-Os isotopic analysis of Molybdenite shows that the age of mineralization is 210~212.7Ma,can determine the age Hede tungsten tin polymetallic mineralization ore for late Indosinian epoch,and the ore bearing granite body in uniform background,main part of anatexis inferred its material derived from the crust of silicon and aluminum layer,granite type generally refers to the shell(source)or modification of continental crust remelting type.(4)The relationship between mineralization and crust transformation of the granitic intrusions closely,ore bodies distribute in rock mass inside and outside contact belt,follow the order from Portland,evolution,sulfide,oxide carbonate process,from the development of high temperature to low temperature hydrothermal gas-liquid phase,but its main mineralization into gas post magmatic hydrothermal stage.The deposit belongs to magmatic gas-liquid filling metasomatic deposit.The relationship between greisenizatio and tungsten mineralization closely,greisenization developed more intense vein W-Sn mineralization is stronger,so the greisenization alteration for the tungsten tin mineralization good prospecting marks.