Geological Characteristics And Prospecting Directions Of The Mopanjian Tungsten Molybdenum Silver Deposit In Jixi,Anhui Province

Mopanjian tungsten molybdenum silver deposit located in the Jixi County,Anhui Province is a typical layered skarn type tungsten polymetallic deposit newly discovered in southern Anhui Province in recent years.The tungsten-molybdenum-silver mineralization mainly occurs in the contact zone between the manganese-calcium sandstone-sandstone in the upper part of the Xiuning Formation and the early Yanshanian granodiorite of the Nanhu.In recent years,quartz vein type tungsten mineralization has also been found in the western part of the mining area.Through the field geological exploration and comprehensive research,this paper systematically expounded the geological characteristics of ore deposit geological background and characteristics of the ore bodies,and comprehensively analyzed the ore-controlling factors of the deposit.This research also summarized the ore-forming rules and compared the similar deposits by combining the main and trace elements.in the same ore-forming geological background in the region.The ore-forming ages,metallogenic geological conditions,magmatic rock formation and ore genesis of the Mopanjian tungsten-molybdenum silver deposit were analyzed and the regional mineralization prospects were predicted,and next prospecting direction were also predicted.The main achievements and new understandings are as follows:The orebodies of the Mopanjian deposit are mainly distributed in the upper part of the upper calcific-manganese siltstone formation in the southern part of the Xiuning Formation.The overlying roof of the ore body is the tuffaceous mudstone at the bottom of the Leigongwu Formation,and the bottom layer is the silty sandstone and mudstone in the middle part of the upper part of the Xiuning Formation.The ore bodies are located at the turning end of core of Mopanjian syncline,and the ore-forming rock is the early Jinshan granodiorite in the Yanshanian.The ore bodies are distributed in layers in the rock contact zone.The ore type is mainly skarn type,and the main metallogenic stage is late skarn stage and quartz sulfide stage.The ages of the intrusion and mineralization are similar,both were formed in the Late Jurassic period namely the early Yanshanian mineralization.The study of the geological characteristics of the deposit indicates that the formation of the deposit is the result of the interaction of stratigraphic-tectonite-magmatic rocks.The ore-forming is controlled by the uranium-bearing strata of the Xiuning For-mation,the skewed transition end and the contact zone of the rock mass.The magmatic rock are the main sources of ore-forming materials and the Xiuning Formations and structures control the shape and scale of ore bodies.The magmatic rocks in the mining area is I type granites.The diagenetic materials mainly come from the partial melting of the lower crust and are contaminated with mantle materials.The ore-forming dynamics setting of the area is local extension environment under regional compressive stress.Based on various characteristics,the Mopanjian tungsten-molybdenum-silver deposit is a strata-bound skarn-type tungsten-molybdenum-silver deposit associated with Yanshanian magmatism.According to the metallogenic regularity and genetic type analysis of the deposit,the Yanshanian granodiorite intruded into the contact zone of the carbonate or calcareous rock strata and the NE-trending structural fracture zone in the rock mass.The intersection of the northeastward fault and the northwestward fault is a favorable prospecting direction for the tungsten-molybdenum polymetallic ore exloration in this area.