Study On Metallogenic Tectonic Dynamics Mechanism Of Hydrothermal Uranium Deposits In South China

In this paper,the metallogenic dynamics simulation model of Xiangshan basin and that of Changjiang orefield is established by using numerical simulation model.Tectonic diffusion model are used to and predict the resource potential in South China.The Changjiang ore field is simulated by numerical simulation method,and the stress field and fluid evolution are analyzed,and the best metallogenic target and metallogenic area.On the basis of previous studies,the evolution laws of stress field,fluid ion concentration and fracture permeability in Xiangshan basin are analyzed again.In addition,a new mineral resource potential estimate model is introduced and applied to the prediction of hydrothermal uranium resource potential in South China.The best exploration depth and potential resources are predicted by using the tectonic diffusion model.The final conclusions are as follows :(1)Geological entity models of section and plane in Xiangshan area and Changjiang ore field are established.The dynamic simulation of uranium mineralization process is carried out.According to the strain area,stress field distribution and high porosity area,it is predicted that the central part of the Changjiang ore field(especially the Mianhuakeng fault and Youdong fault)and the surrounding rock mass are the best metallogenic target area.The surrounding rock mass and the upper rock mass of the Changjiang ore field are the favorable metallogenic location.(2)In this study,the spatial and temporal distribution of strain and fluid ion evolution in the high stress area of Xiangshan Basin were analyzed.The result shows that southwest direction of Zoujiashan-Shidong fault zone and the middle and deep fault zone(about 1500m),especially the rhyolite dacite of Daguding Formation and the porphyroclastic lava of Erhuling Formation,have the best metallogenic potential;(3)The results shows that there are 459 undiscovered potential hydrothermal uranium deposits in South China,including 86 near the surface,348 in the depth of 0.5-1km,and 25 in the depth of 1-2km.Uranium deposits are mainly concentrated at a depth of0.5-1km,accounting for 75.8% of the total deposits.The total resources of these potential granite-type and volcanic-type hydrothermal uranium deposits exceed 550,000 tons.It shows that there are great uranium prospecting potential in this area,most of the deposits are denuded within2 km of the crust,and concentrated in the shallow in the depth of 0.5-1km the crust.Taoshan-zhuguang metallogenic belt and Ganhang metallogenic belt are metallogenic prospective province.