Metallogenic Geological Conditions And Metallogenic Prediction Of The Weidong Fluorite Deposit In Inner Mongolia

There are abundant fluorite resources in Ulanhot area,Inner Mongolia.The regional geotecture is located in the central part of geosyncline fold system of Inner Mongolia,and the location is the northeastern end of the Zhesi-Linxi Syncline in the northeast of the late Variscan geosyncline fold belt in Suniteyouqi.It is mainly composed of Jurassic volcanic-sedimentary strata and Yanshanian granite.In this work,fluorite deposit is taken as the research object.Based on the field geological survey and laboratory analysis& test,this paper analyzes the ore-forming geological conditions of fluorite deposits in Weidong area.Through the basic geological analysis of the study area and the combining method of geological and geophysical prospecting of portable gammaray radiometric survey,metallogenic prediction is carried out in this area,and then the target area is delineated.The main achievements and understandings are as follows:1.A northeast trending fault in the area has been observed and studied.This fault is located at the contact zoing of stratum and the ignore rock with trending of 330°?60-70°.This fault is a normal fault with tensile characteristics,which controls the output of the fluorite ores,and it is the main ore-control structure of the fluorite deposits in the area.2.Microthermometry of fluid inclusions was carried out for the main ore bodies in the mining area.The homogenization temperature of inclusions ranged from 169 to 194?,and the average temperature was 186?.The salinity of ore-forming fluids is calculated to be between 0.35 wt.% NaCl equiv and 5.41 wt.% NaCl equiv,with an average 3.14 wt.% NaCl equiv.On the basis of the above data,the density and pressure of the fluid are calculated,and it belongs to the low density fluid.The ore-forming fluids in this area are mainly characterized by medium-low temperature,low salinity and low density.It is inferred that the ore-forming fluid mainly come from meteoric water,and the ore-forming depth is near the surface.Therefore it belongs to mesoepithermal fissure filling deposit.3.On the basis of summarizing and analyzing the characteristics and metallogenic g eological conditions of the ore bodies in the study area,the hidden and semi-hidden fluo rite ore bodies in this area are predicted by using the comprehensive method of Geology and gamma radioactivity measurement for the shallow overburden..Three metallogenic target areas(A,B,C)have been delineated.Among them,target area A has been verified,showing that there are better fluorite ore bodies in the deep part and has vertical zonin g characteristics.It further shows that the area has good prospecting potential.