Simulation Of Ore-controlling Structure And Metallogenic Tectonic Stress Field Of Dulong Zinc-tin Polymetallic Deposit In Yunnan

The Dulong tin-zinc polymetallic deposit is located in the southwest of the South China plate and at the junction of the Indochina,Huaxia and Yangtze plates in the tectonic position.On the basis of field geological investigation and combined with the exploration results of mining area,the ore-controlling structure analysis of Dulong Mine deposit is carried out by summing up and analyzing the geological characteristics of the deposit.The main ore-controlling structural styles in and outside the mining area are analyzed,the mechanism of ore-controlling structure is discussed,and the ore-controlling model of deep and peripheral structures in the mining area is preliminarily established.The tectonic stress field in the metallogenic period in this area is simulated by using Ansys Workbench software.The deep and peripheral prospecting direction has been studied by comparing and analyzing the simulation results and the existing exploration results.The main research results are as follows:1.The contrastive analysis of the relationship between regional structure and mineralization shows that the early Cretaceous is the main metallogenic period of tin polymetallic deposits,which corresponds to the regional extensional tectonic background at the same time.The structural analysis of the mining area shows that the main body of the study area is slippage deformation.,forming three ore-controlling faults F₀,F₁ and F₂ in the north-south direction.F₀ and F₂ provide barriers for mining areas.F₁ are located in Xinzhai rock formation and provide channels for ore fluid migration.A large number of secondary folds and faults are formed on both sides of the fault.2.The analysis of tectonic ore control shows that the fault plane and the secondary structure control the shape and the space distribution of the orebody:the fault is distributed in the north-south direction on the plane,the orebody on the section is filled in the secondary fault or tensile vein,and the saddle is distributed at the turning point of the fold or on both wings.3.Through the simulation analysis of tectonic stress field in metallogenic period,the Maximum Shear stress,Von-Mises stress,Maximum elastic strain,Strain energy,Temperature and other anomalies are generally distributed in between F₀ and F₂,which are obvious in the middle of the mining area.At the same time,the stress-strain value is more obvious because of the existence of metallogenic rock mass and the change of rock mechanical properties in the deep part.4.Based on the simulation of ore-controlling structure,deposit geology and metallogenic tectonic stress field,it is proposed that the action sites of deep and main faults are extended along the tendency of Xinzhai rock formation.Along the strike to the south,the deep part and the tectonic fracture zone and the metallogenic rock mass junction are favorable metallogenic spaces.