Study On The Source Analysis And Sedimentary Characteristics Of The Fifth Section Of Kizilsu Group In Uragen Lead-Zinc Ore,Xinjiang

Uragen lead-zinc ore which is located in the Kizilsu Kirgiz Autonomous Prefecture of Xinjiang,Wuqia County,is currently China's second largest lead-zinc ore.The main ore bed of Uragen lead-zinc ore is the fifth section of the Kizilsu Group,the ore bodies are layered and tabular.The former study is mainly concentrated in the ore genesis,ore-forming materials and ore-forming fluid.The mining area has a high degree research about Geology and mineral resources.A wealth of information has been accumulated,but there are few studies on the sedimentary characteristics and provenance of the strata in the mining area.When doing geological exploration in the outer-ring of Wulagen lead-zinc mine,the author focuses on the study of the sedimentary characteristics and provenance of the fifth section of the Kizilsu Group which is host rock.Based on the combination of field observation and indoor geochemical test and analysis,the relationship between provenance,sedimentary characteristics and mineralization is studied,and the following understandings are obtained:1.In the fifth section of the Kizilsu Group,the percentage of sandstone,the sandstone composition,mineral maturity variation and stability,relative content of the heavy mineral,ZTR index and the similarity of REE distribution patterns show that the provenance of the study area is mainly from Wulagen uplift in the Southwest.2.The characteristics of the cuttings and the correlation coefficient of heavy minerals show that the parent rocks are mainly metamorphic rocks and igneous rocks.The characteristic parameters of rare earth elements and REE pattern curves reveal that the fifth section of the Kizilsu Group sandstone has characteristics of a deficit of light rare earth and enrichment of heavy one and negative Eu anomaly.Consequently,the source rocks may be neutral magmatite.However,the Ce and Ceanom values indicate that the paleo water medium is a weak oxidation and weak reduction environment,which may be in an environment of sea land transition,which is beneficial to the enrichment of metal minerals.3.Based on the analysis of the gravel,the parameters of the rock characteristics,such as the composition of the gravel,the content of the gravel,the gravel diameter of the gravel and the roundness of the gravel,are obtained.By projecting these five parameters(Conversion value(O),mean value(Mz),standard deviation(6),skewness(SKI)and kurtosis)to coordinate investment created by Freedman,It shows that the sedimentary facies of the fifth section of the Kizilsu Group is delta facies,which is characterized by gravity flow and traction flow.4.The sandstone triangular diagram shows that the sandstone types of the fifth section of the Kizilsu Group in the study area are feldspar lithic sandstone and lithic arkose which reflects the characteristics of near source accumulation.Seven types of probability cumulative curve type of sandstone grain size which is reflecting the fan delta sedimentary environment in the study area are summarized.5.On the basis of deep research on the characteristics of petrology,grain size and sedimentary structure of the fifth section of the Kizilsu Group in the study area,the fifth section of the Kizilsu Group is divided into three subfacies:fan delta facies,fan delta plain,fan delta front and fan delta debris flow deposits and five microfacies:braided channel,underwater distributary channel,interdistributary bay and estuary dam.6.Profile comparison and sedimentary facies show that the ore body mainly occurs in the braided channel micro facies of fan delta front and the underwater distributary channel microfacies of fan delta plain.The mineral source with the background of high Pb and Zn value was transported to the study area to form the source layer.The ore-forming fluid migrated along the fault to the braided channel sandstone and the distributary channel sandstone which have the best physical property.After the chemical reaction with organic matter,H2S,HS-and so on,the ore-forming fluid enriched into lead-zinc ore.