Mineralogy Of Chalcopyrite From The Typical Tungsten And Lead-zinc Deposits In Southern Jiangxi

The area of Southern Jiangxi is the“capital of tungsten”in China.Under the guidance of intensive study of metallogenic regularity,mineralization and“five floors and basement”prospecting model,we not only got great breakthrough in the deep exploration of tungsten deposit,but also achieved fruitful deals in the deep ore prospecting of Cu-Pb-Zn-Au deposit in recent years.The W-Cu-Pb-Zn polymetallic ore in Southern Jiangxi has become a hotspot in the current research,the deep exploration and experimental research has carried out a lot of research work in this area,which provides an important foundation for the deep mineralization of this area.As a typical representative of tungsten and copper polymetallic ore deposit of Taoxikeng tungsten polymetallic deposit and Niuxingba Au-Ag-Pb-Zn deposit in South Jiangxi,there are a large number of copper minerals-chalcopyrite and even could be used for industrial mining.In this paper,chalcopyrite is the main research object,adopt the working methods for the investigation and laboratory test analysis combined with field geological survey,and the mineralogical characteristics and geochemical characteristics of chalcopyrite are carried out by comparing.The main achievements and innovations are as follows.(1)Chalcopyrite exists as a related mineral and its distribution shows a certain reverse zoning phenomenon with obvious high Ag and low Au in tungsten deposit,although as the main ore minerals and the content of Ag and Au has a low degree,chalcopyrite could contain independent Au-Ag mineral and as a carrier mineral in lead-zinc deposit.(2)Chalcopyrite shows the same chemical characteristics of iron loss and sulfur rest,showing the characteristics of middle and low temperature mineralization.(3)The content changes of chalcopyrite in the main component is small and there is a big difference between the types and the contents of trace element in the two deposits.Metallogenic element is relatively complex with the combination of high temperature element and a little low temperature element in tungsten.although in lead-zinc deposit,metallogenic element is mainly formed with low temperature element and a little high temperature element.(4)The content of REE and characteristics of chalcopyrite in two deposit are similar and still exist some differences.The fractionation of REE is obvious and uneven,also the distribution patterns of chalcopyrite show characters of slightly LREE deficited and negative anomalies of ?Ce in tungsten deposit,the fractionation of REE is not obvious and the distribution patterns of chalcopyrite show characters of slightly LREE riched,also negative-positive anomalies of ?Ce in lead-zinc deposit.(5)The characteristics of sulfur isotope composition of chalcopyrite in two deposits are similar to that of sulfur source is relatively simple and both derived from deep magma.(6)The bismuth element are both similar and different in two deposits.In tungsten deposit,bismuth is existed in bismuthinite,bismuth and galenobismutite and other minerals with obvious characteristics of the vertical zoning,there exist high content of Ag in bismuth minerals and involved in the composition of bismuth sulfosalt minerals.Bismuth is only existed in bismuth sulfosalt minerals and the complex composition,mostly without Ag in lead-zinc deposit;the sequence for formation of chalcopyrite and bismuth sulfosalt minerals are basically consistent in the two deposits.In conclusion,there are similarities and differences in typomorphic mineralogy and geochemical characteristics,showing the identity and diversity of polymetallic mineralization and and metallogenic process in Southern Jiangxi.For the middle and low temperature Cu-Pb-Zn-Au-Ag mineralization,the chalcopyrite is not only ore-forming material,but also is one of the main carrier minerals of Au and Ag.For the high and middle temperature W-Sn mineralization,chalcopyrite is an important component of sulfide combination in the relatively late stage of the mineralization,showing that the chalcopyrite can serve as an indicator of ore prospecting and indication for different mineralization in deep.