Constructing Three-Dimensional Models And Estimating Reserves Of Jiama Polymetallic Copper Deposit, MoZhugongka County,Tibet

The Jiama polymetallic copper deposit locates in mid-south of Gangdese-Nyainqentanglha plate ,Tethys-Himalayan tectonic megaprovince, Tibet. Main(Skarn ore body) ore body is hosted in stratiform structural zone between limestone,marble of the upper Jurassic and sandy slate,chert of the low Cretaceous, and is controlled by sub-fold produced regional thrust nappe structure and ore field gliding nappe structure. The morphology of ore body is stratiform,thick plated,beded,lenticular ,and the whole form is"chair".The length is over 3000m in strike with NWW and over 2000m in dip with NNE.Main ore can be clearly divided into two parts: The steep ore(lead-zinc ore) strikes almost EW, and the dip angle is 60°～70°. The gentle ore(Copper-molybdenum ore) strikes almost NE, and generaly less than 20°indination.Based on the study of Geological ore body ,to construct three-Dimensional Model for Estimating Reserves,Stratigraphic Model,Digital Terrain Model ( DTM) and so on by micromine.The statistical analysis of the sample indicated that 5m is a reasonable combo-like long.Through fitting semivariable functiong,as for the gentle ore(Copper-molybdenum ore) in strike,the gold value of copper is 0.45 and the range of variation is 150m;as for the steep ore((lead-zinc ore) in strike,the gold value of copper is 0.58 and the range of variation is 125m.The rationality and feasibility of models and eatimated parameters are validated by volume validation and cross validation. Grade -tonnage of relationship shown that all the ore badies are filled with copper mineralization. Most of the metal is concentrated primarily between 0.1% and 1.9%.The results indicate,Micromine can construct mine database,which has practical applications,high efficiency,improved reliability. We can conclude that using Micromine for the deep mineral exploration and prediction is a viable. It is also suitable for the study of variation.The results of estimating reserves can be directly used in mining design,and the combination of exploration and production becomes reality.