Three-Dimensional Digital Mineral Deposit Model Analysis And Deep Prediction Of Jiama Copper-Pollymetallic Deposit,Tibet

Jiama copper polymetallic deposit is a porphyry-skam-hornfels type copper-polymetallic deposit related to ore-forming precess of porphyry in the Gangdese metallogenic belt The deposit has been discovered since 1951,and has launched a number of geological exploration work.Recent exploration work and geological studies reveal the genesis of the deposit,and establish the geological exploration model.Jiama copper polymetallic deposit is a large scale deposit.Jiama deposit now controlled copper,molybdenum,lead,zinc,gold,silver reached a large amount of resources,and has good prospects.Jiama deposit has high degree of exploration,rich geological data,and already has a large number of research results.But predecessors on Jiama deposit model and prediction research,mainly through textual description and two-dimensional graphical expression,this approach can not represent deposit distribution and spatial variation in three-dimensional view.This thesis base on the mining deposit model,take the metallogenic theory as a guide,use the true three-dimensional perspective to do the following research:(1)Through collecting the geological studies and mine production data,and summaring the geological background and genesis types,the thesis determined deposit types based on the existing geological work and related research.The thesis use MinESoft three-dimensional geological modeling software to build the three-dimensional digital model,such as three-dimensional surface,three-dimensional drilling,three-dimensional geological body(stratigraphic model,rock model),three-dimensional ore-controlling structure interface,three-dimensional mineral alteration,and three-dimensional deep geochemical model as a whole.(2)On the basis of the three-dimensional deposit model,the thesis use three-dimensional integrated analysis method to analyze the relationship between the main ore mining,the spatial element abnormal.The thesis found that each element anomalies overall EW zonal distribution,combination of elements and features from south to north was regularity.The North East part of Jiama,there may be more stable deep layered ore body,and it is worth conducting further exploration work.(3)Using an algorithm fitting for layerd gelogiacal surface based on inverse distance weighting method and marching cubes to simulating the ore-controlling structure interface of Jiama deposit.The thesis analyzed the mine stratigraphic contact interface control relationship with the main orebody,as well as key elements of metallogenic control action,and summarized the structural interface is a vital indicator.(4)By studying the vertical wall rock alteration zonation,the thesis chose typical cross section to study the distribution characteristics of alteration minerals,and thus use three-dimensional visualization technology to build a three-dimensional model of alteration minerals.The alteration mineral zonation in Jiama is divided into hornfels alteration and skarn alteration types.(5)The thesis established a three-dimensional geochemistry model of each element and summarized the spatial distribution of the elements through the middle slice and exploration line slice.Using element zoning sequence method calculated vertical and horizontal element zoning sequence,and found that the metallogenic elements distribute consistently in the vertical and horizontal directions.Jiama deposit performance in shallow low temperature elements Pb,Zn to high temperature elements Cu,Mo distribution characteristics,and constitute a complete magmatism related element zonation.Through the discussion of element ratios,the thesis suggested that deep fluid source may be located in deep area or deep area exist concealed porphyry.(6)The thesis summarized the indicators based on three-dimensional digital Jiama deposit model,extracted prediction elements,established three-dimensional predictive models,used three-dimensional weight of evidence prediction method to calculate the predictive factors favorable degree of mineralization and delineated the target of Jiama deposit.