3D Visualization Modeling And Application Study Of Porphyry-Skarn Copper-Au Deposits In Beiya Area

Beiya porphyry-skarn Copper-Au deposits located at the middle segment of the gaint Jinsha river-Red river tectonic-magmatic-metallogenic belt,which is the typic porphyry Au polymetallic deposit in the southeastern margin area of the Qinghai-Tibet plateau.For the past few years,the shallow part geological structure and resources of the deposit have been preliminarily revealed.However,the limited knowledge of the deep ore-controlling structures and mineralization conditions restricted deep prospecting.In this paper,we focused on the geological body from the surface to 1000 meters underground of Wandong Shan ore block.Through adoption of advanced geologic model building soflware-GOCAD and proper modeling methods,we realized 3-D visualization of WandongShan ore block.The main conclusions are as follows:(1)Finishing the digitization of the intrusion,stratum and ore body boundaries in the prospecting line profile map,adopted the non-process modeling method,we built surface and body models of the stratum?tectonic,intrusions,ore body of the Wandongshan ore block,realized the transparency of deposit.(2)Based on drilling data and Sgrid of ore body,we realized 3-D visualization of grade distribution model for the first time by using ordinary kriging interpolation method-Main conclusions as follow:?The assessment of Au reserves in Wandongshan section comes out the number of 246146 kg.?Through analysis of high garde ore body sgrid(>4g/t),we speculate that there is a deep buried fracture in Wandongshan strike parallel to 40°,which might be the target for further exploration;?The mismatch between thick part of ore body and high garde sgrid indicate that Beiya au deposit has suffered multistage mineralization,the growth of fracture and ore body prior to enrichment of au resources-The fracture formed in the early metallogenic stage,while the enrich of au resources in the late metallogenic stage.(3)By analysis of spatial coupling distribution of subsurface geological body in Wandongshan under the condition of 3-D visualization space.The results shows fault is the priority key factors which eontrolled the growth and spatial distribution of ore body and intrusions,while the strata interface is the secondary factors.In general,the fault-intrusion-stratum co-control the ore development and deep distribution.(4)Gravitational prospecting and magnetic geophysical method corresponding to Wandongshan ore body which shows high magnetic anomaly and low gravity anomaly.So we speculate that the high magnetic anomaly and low gravity anomaly area would be the metallogenic prospective area.