The Research On Geology, Geochemistry Features And Its Genesis Of Yuele Lead-Zinc Deposit In Northeastern Yunnan Province

The tectonic position of the Lead-zinc deposit in Yuele of Daguan lacated in the Northern of the northeast Yunnan fold belt which lacated in the southwest margin of the Yangtze paraplatform and in the eastern of Panxi rift.The deposit is a newly discovered deposit in recent years,It has explored in (332+333) class Lead-zinc reserves about50,000tons at present,It remain in good prospecting potential.But there are significant differences between the deposit and the known lead-zinc deposits in northeast Yunnan,Mainly for multi-layer strata’s carbonate Accommodate the ore, stratiform and vein ore bodies coexist,Lead-zinc and Lead-copper of the orebody co-location and associated with salt layers and barite.Thus,Identify their geological characteristics,geochemical characteristics and analyze its genesis will undoubtedly promote the awareness and understanding about the mineralization of the Lead-zinc deposits in the northeast Yunnan,In this paper,On the basic of full collect the project team preliminary results and information and the system field geological survey,We have carried out the basic geological survey,geological observations,rock and mineral analysis,formation geochemical analysis of rocks and minerals and C,H,O,S,Pb,Sr isotopic trace comprehensive research work,etc,So I have got the basic information about the deposit geological-geochemical characteristics,then put forward its genesis understanding,Thesis research and understanding as follows:(1) The Pb-Zn-Ag orebody in shallow portion predominantly output as steeply inclined veins and stockwork veins,It strictly controlled by the NW-trending,NNE trending tenso faults,Partially,The interlayer fracture zone formed the stratiform ore body, Deep (Pb-Ag) Zn ore body was layered,layer-like stockwork output,It strictly controlled by the salt layers and the underlying carbonate strata,Cu-Pb-Ag vein and net ore body output on the plate of the F1fracture in the west of this deposit. It Predominantly output as steeply dipping and stockwork vein and strictly controlled by the SN-trending NWW tenso faults and joints..The three forms of The ore bodies pattern a mineralization of Multi-layer multi-pulse".Ore-bearing strata are mainly are lower ordovician shizipu group(O1s),lower silurian huanggexi group(S1h),middle silurian sifengya group(S2s),and middle silurian dazhailu group(S2d),The lithology is mainly limestone,carbon argillaceous limestone,dolomitic limestone,the gray matter dolomite and containing long quartz sandstone.lt belongs to a Paleozoic shore-shallow marine clastic rocks-carbonate buildup.(2) The main ore minerals is galena,sphalerite,pyrite and a small amount of bornite and chalcopyrite,etc.Gangue minerals are mainly barite,calcite,dolomite,and a small amount of quartz,fluorite,gypsum,etc.Local oxidation of the ore common see the malachite,azurite and calamine.The ore vein mainly have the vain,stockwork and the euhedral subhedralstruture,and have Euhedral, subhedral, anhedral account the residual and accountable dissolution texture,The mineralization can be divided into diagenesis and hydrothermal ore-forming hydrothermal mineralization,and the hydrothermal ore-forming hydrothermal mineralization can be divided into Cu-Pb sulfide stage,Pb-Zn-Ag sulfide stage and carbonate stage.(3) Wall rock alteration including carbonate(it mainly is calcitization and a small amount of dolomitization),baritization,pyritization and a small amount of silicification,fluoritization,plasterization and fade,etc.It has a clear zonation characteristics.both in horizontal and vertical direction(4) After a study of the geological characteristics of the Lead-zinc deposit in Yuele of Daguan,known the deposit obviously Bedding the epigenetic hydrothermal filling metasomatic mineralization characteristics and considered the three forms of the ore body within the deposit is formed in the same set of ore-forming fluid system.(5) the ore formation Elemental geochemistry studies have shown that the carbonate in the lower silurian huanggexi group(Sih),the middle silurian sifengya group(S2s) and the middle-upper ordovician dajing group(O2+3d) may be provided source materials for Pb,Zn ore-forming elements,and the carbonate in lower ordovician shizipu group(O1s) may be provided source materials for Cu ore-forming elements,and may bealso provided source materials for Pb,Zn ore-forming.(6) Derived from meteoric by the H,O isotope of the quartz fluid inclusions in the mineralization stage Known ore-forming fluids comes from atmospheric precipitation,fluid inclusions in calcite C,O isotope know the carbon comes mainly from carbonate rocks (7) Contrast to the typical MVT lead-zinc deposits at home and abroad show that, The Lead-zinc depositin Yuele of Daguan had many similarities and the unique nature itself with the typical deposit, but it also belong to MVT type Lead-zinc deposits.