Numerical Simulation And Prospecting Prediction Of Tectonic Stress Field During The Metallogenic Period Of The Yangla Copper Deposit, Northwestern Yunnan

The Yang la copper deposit is located in the middle of the Jinshajiang tectonic belt,which is one of the representative deposits in the northwest of Yunnan,which is a typical epiphytic superposition of the copper-polymetallic metallogenic belt in the northwestern Yunnan,Skarn type deposits.lt is obvious that the Copper deposits are controlled by the structures in this region,to study the tectonic ore-controlling is of great significance.Based on recent results of exploration and the regional geological reatures,this dissertation performs several case studies on typical mining areas,for example the Linong,Jiangbian and Lunong,to investigate the tectonic structures that controlled the ore formation and the mineralization regime of the copper deposits in the Yangla area.The results would be indicative for the future ore explorations in this area.The main deep fault structure in the study area is the major structure as passageway for rock and ore fluid,and its derived fault structure is the channelsof magma,hydrothermal and mineral transport.The host and storagestructures of the ore include secondary co-directional,derived fracture,secondary fold axis,turning end,fracture Belt,interlayer extrusion zone and crushing zone,especially the structure of the intersection and conversion site.Most ore bodies are produced in the structural fracture zone or interlayer fracture zone.The simulation results reveals that the regional tectonic activity.The maximum principal compressive stress anomalies controlled the development,distribution and direction of regional joints and fractures.The abnormally high shear stresses control the development of the development of the secondary fractures in this region,and the subsequent development of veins.The local stresses also influenced the pore fluid pressure among rock fractures,thereby controlling the fluid migration.The metallogenic fluid migrates from the high pressure area to the low pressure area and accumulates in the liw pressure area.When the high pressure fluid migrates to the low stress areas,the fluid pressure is reduced,and the dissolved minerals in the fluid are more conducive to deposit and fulfill the mineralization.Based on the study of the relationship between the numerical simulation results of the structural stress field and the spatial distribution of the ore body,the prospecting direction is summarized and three favorable target areas are put forward.