Geologicalcharacteristics And Prospecting Potential Of Baoshan Fluorite Deposits In Linxi, Inner Mongolia

Linxi is located in Chifeng,Inner Mongolia.It is geotectonically positioned in the composite partof the EW strikingPaleo-Asian Ocean tectonic metallogenic region and the NNE striking west Pacific Marginal metallogenetic region,which are world's two big tectonic metallogenetic regions and also the northern marginal hyperplasia beltof North China.Linxi is known as “township of the non-metal”,and much research has ever been done on thefluorite ore depositin its north,controlled by the NNE striking compression and scissor fracture;whereas,little is known about the fluorite deposit controlled by EW striking fracture.Therefore,in order to make up for the relevant research,the thesistookBaoshan fluorite deposit in Linxi as the main research object,and summarizedthe ore-forming geological characteristics of Baoshanfluorite depositofEW striking tectonic ore-controlling.Under the guide of modern deposits and metallogenic prediction theory,field geological survey and indoor test analysis were conducted to make apreliminarydiscussion to themineral deposit genesis.Moreover,the deep resources were also evaluated and predicted,which mainly brought about the following understandings:1.There are altogether eight silicated alterationbelts in different directions,among which three are fluorite mineralization belts.F1 main orebody,as the main research object,has the same output characteristics with the EW strikingmain fracture structure.Its ore fabric and wall rock alterations are featured as planar and vertical zoningalong the fracture,which is strictly controlled by EW striking fracture structure.ore deposit can be attributed to the fissure filling depositcontrolled byfracture.2.Through thegeochemistry analysis of the rare earth elements in the surrounding rocks ofthe fluorite andstratum in theearly and late metallogenic stage of main mineralization belt,it is found that the fluorite ?REE in early stage is lower,with rich LREE;while fluorite ?REE in late stage is higher,with rich HREE.Due to the abnormity of Eu,it can be inferred that the ore-forming fluid was evolved from oxidation to restoration.3.Based on the research ofthe fluid inclusion of the fluorite in the early and late metallogenic stage of main mineralization belt,it is showed that the average temperature of the fluid inclusion in the early and late metallogenic stage is mainly between 150~180?,and the salinity isamong 0.18%~0.80wt%NaCleqv,which indicates that Baoshan fluorite deposit is a low temperature and low salinity hydrothermal deposit.4.With the help of REE analysis and inclusions data,and based on the previous research results,it is speculated that F mainly comes from surrounding rock;Ca is derived from the surrounding rock and Linxi group;Ore-forming fluid comes from atmospheric precipitation.Water-rock reaction occurred between surrounding rock andore-forming fluid during migration in deep space,which caused the enrichmentof CaF2 and the precipitate in ore fluid.5.Based on the ore-forming geological characteristicsand vertical zoning of the deposit,it is considered that reveal of the mining area is still in the siliceous lid and the head of ore body,and the deep of the head of ore body still has great resource potential.