The Study Of Ore-forming Characters And Prospecting Orientation Of Lead-zinc Deposites From Chalukou To Tianshuihai Ranges In West Kunlun, Xinjiang

Chalukou to Tianshuihai Region in West Kunlun is the highly anticipated lead-zinc mineralization belt in Xinjiang,the area is the largest lead geochemical and the second largest zinc geochemical anomalies blocks in Xinjiang.Recently,a growing number of lead-zinc deposits(ore occurrences)be discovered and evaluated Continuously,Some have reached the medium-sized,and have the prospecting potentialion to be the largest lead-zinc mineralized zones in Xinjiang and even in China.This paper is based on the extensive collection of regional geological?geophysical and geochemistry and the lead-zinc oreoccurrences data and informations,through the field investigation?sampling analysis?mineral assemblages?fluid inclusion?isotope test and some other methods,we analysis and research the geological characters of the typical deposits?ore-controlling factors and metallogenic condition,we summary the regional metallogenic regularity and have an objective evaluation of its prospecting in order to provide reference for the area of lead and zinc prospecting work,The main achievements and recognizes we obtained as follows.1.Based on the analysis and research of the Geological Characteristics of numerous lead-zinc deposits or ore occurrences in this area,we consider that the lead-zinc depoists mostly located in the nearby Qiaoertianshan-Chalukou fracture belt and the Kalakunlun Mesozoic continental margin basin.2.Summary contrast made,research district upper chalk tielongtang Group(K2tl)?the middle jurassicLongshan Group(J2l)and Shenxianwan Group(P1-2Sx),and fore-land basin neritic facies carbonate rock is the main ore-host strata,lead zinc mineralization may related to the basin thermal brine activities,ore genesis falls in Mississippi Valley type(MVT),and SEDEX.3.Studies on two significant lead-zinc ore deposits represented by Duobanshan and Baotashan deposits have shown that the lead-zinc ore bodies in this area mainly occur in fractures,karst caves,planes of unconformity and interlayer fracture zones.The orebodies are usually of meters to hundreds of meters long,few metres to dozens of meters wide with complicated morphologies and various occurrences including statoid and vein types.Generally,the ore minerals contain galena,sphalerite,cerusite and the nonmetallic minerals include calcite,dolomite and gypsum.These rocks appear vein-type,disseminated,breccias-type or massive structures and fine to middle grained or porphyroclastic texture.Useful components include Pb and Zn and usually companied withAg.Epigenetic superimpose characteristics are obvious.4.Revealing that hydrothermal calcite ore with sulfide minerals have almost uniformly rare earth and trace element geochemistry,mineralization accompanies with significant carbonation,alteration of hydrothermal fluids and lead-zinc ore-forming fluid are of the same or similar to basin fluids.Fluid inclusion homogenization temperatures concentrate around 207??262?,salinity varies from 6.30%?7.73%NaCleq,ore-forming fluid is mid-low temperature and mid-low salinity.5.The composition of C and O in calcite of ore ranges are between ?13CPDB=3.44‰?5.09‰,18OSMOW=23.09‰?26.79‰ respectively,which indicate the CO2 in hot fuild mainly from marine carbonate.Isotope of S and Pb in ore mineral indicates that the composition of S in galena from ?34SV-CDT =-10.55‰ to 1.01‰,the composition of Pb is 206Pb/204PbS=18.7398?18.7433,207Pb/204Pb=15.7025?15.7040,208Pb/204Pb=39.092 9?39.097 1.The S is not the single source,the source of ore is from host strata.6.Based on the research of typical deposits and combine the regional geological?geophysical and geochemistry data and informations,we pointed out that lead and zinc geochemical anomalies are the important prospecting guides for lead-zinc deposits,the northwestern run fracture is the important ore-controlling factors?Mesozoic Strata is the important host strata.7.With the metallogenic geological setting in the study area and the metallogenic characteristicsore-controlling factors?prospecting criteria and metallogenic regularity,Discussion on lead-zinc ore-searching direction,we think the limonitization?carbonation is an important alteration type Pb-Zn ore prospecting direction of five...