Study On Geological And Geochemical Characteristics And Genesis Of Shuibutou Manganese Carbonate Deposit In Qiling Basin

The Qiling Basin is located in the northwestern part of Yongzhou City,Hunan Province.It has rich manganese ore resources,but the genesis of manganese ore in the region is complex.Therefore,this article takes the Shuibutou deposit in the area as the main research object.This article systematically studies the geological characteristics and chemical composition of the deposit through X-ray diffraction,scanning electron microscopy and geochemical analysis,and analyzes the source of ore-forming materials and ore-controlling factors,Revealing its metallogenic model.The main achievements and understandings of this paper are as follows:The Shuibutou deposit mainly occurs in the Gufeng Formation,with shale sections and manganese-bearing limestone sections being the main ore-bearing horizons.Manganese deposits are mainly controlled by fold structures,that is,manganese deposits are produced in syncline structures,and no manganese deposits are produced in anticline structures.The main structures of manganese ore include unequal-grained sandy debris structure,spherulitic structure,mud-like granular structure,argillaceous oolitic structure,etc.The structure mainly includes micro-layered structure,fine grain-stripe structure and disseminated structure.Structure and so on.The mineral analysis results of the ore indicate that its mineral composition is mainly manganese calcite,followed by rhodochrosite,manganese dolomite and a small or trace amount of rhodochrosite.The geochemical analysis test results of the ore samples show that the content of Mn,Si O₂ and Ca O in the major elements is higher,all higher than 20%,the content of P,K₂O,and Na₂O is less,all less than 1%;the content of Cr,The content of Sr,Ni and V is relatively high,respectively 1836?g/g,466.40?g/g,323.40?g/g and 308.00?g/g,followed by Zn,As and Ba,respectively 154.64?g/g,150.20?g/g And 111.16?g/g,the content of In,Ta and Bi is low,all less than 1?g/g;the enrichment factor analysis results show that the enrichment factors of As,Mo,Cr,Sb and Ni are higher,all greater than 10,Tl The enrichment factors of,In,Bi,Sr,Rb,Zr and other elements are relatively low,all less than 1,that is,iron-philic elements and some copper-philic elements are enriched,while the stone-philic elements are obviously not enriched;the total amount of rare earth elements in the ore is 221.33?g/g,of which the content of light and heavy rare earth elements are 198.73?g/g and 22.59?g/g respectively.The ratios of Al/(Al+Fe+Mn),Si O₂/Al₂O₃,Nb/Ta and Y/Ho in the ore all indicate that manganese ore is strongly affected by hot water during the mineralization process,and Fe-Mn-(Ni+Cu+Co)×10 and Log Th-Log U diagrams also illustrate this point.The ratio relationship of V/(V+Ni),V/Cr,La/Ce and?U and the obvious negative abnormality of Ce indicate that manganese ore is mainly formed in an oxygen-deficient reducing environment.Comparative analysis of sedimentary structure background,ore body characteristics and geochemical characteristics,etc.,the manganese carbonate deposit in the study area is a typical sedimentary-hydrothermal deposit,and its formation has gone through three stages:oxidation stage,reduction stage and post-reconstruction stage.