Research On The Fluorite Metallogenic Geological Conditions And Prognosis In Wulijiaobao,Inner Mongolia

The fluorite mining area in the Inner Mongolia Jilin metallogenic belt,located in the collision juncture of the Siberian plate and the North China plate,experienced multi-stage tectonic movement and magmatic cycle.In this region,the widely distributed magmatic rocks and active tectonic movements created favorable conditions for the formation of fluorite deposits.In the researched region,in order to further explore the distribution of underground fluorite deposits,a variety of exploration techniques and field exploration(drilling)engineering is necessary due to severe coverage in the quaternary system.Based on the achievements and data of past scholars,the field survey and sampling analysis of the researched region,the geological characteristics,the alteration of the surrounding rock and the ore characteristics of the fluorite deposit in the researched region are summarized and the mineralization period is preliminarily divided.The fluorite deposits belong to epithermal deposit.The ore bodies are dominated by veins and a small amount are lenticular.The ore body changes regularly in the vertical direction are siliceous top shells,ore bodies and tuffs.Due to the effect of volcanic rocks,the sericitization and siliconization of surrounding rocks occur at the edge of the orebody from inner to external.In the same time,sericitization,siliconization,kaolinization,fluorite mineralization,salinization and pyrite mineralization occur from the top down in the vertical direction.The ore in the researched region is a single fluorite stone.The main ores are in the brecciated structure and massive structure,with self-shaped granular structure and self-shaped or semi-self-shaped granular structure.According to the interspecific relationship of ores,the metallogenetic process can be divided into four stages: the iron-iron stage,the fluorite-quartz stage,the quartz-fluorite stage and the carbonate-fluorite stage.Among them,fluorite-quartz stage and quartz-fluorite stage are major formation period for fluorite.After the relevant information access and laboratory research,we summed up the metallogenic geological conditions in the researched region.In the middle and late Yanshanian area,the researched area is affected by the NE to the dry-obo-pod-Fushi deep fault(F7).After the multi-stage tectonic transformation,the study area forms many secondary structures of NS,which provide ore-hosting,ore-transmitting and ore-matching structure for mineralization.The ore-(K1b)tuffs provide the necessary temperature and ore-forming materials for mineralization by magmatic activities.The temperature and pressure measured by the laboratory inclusions show that the fluorite deposit(K1b)tectonics and ore-bearing structure form at the temperature of about 108~340? and the mineralization average depth of 180 m.Based on the organic combination of geology,geophysics and geochemical techniques,the abnormal area of the researched area was measured by the method of low frequency electromagnetic method and X-ray fluorescence spectrometer,and the area with mineralization potential in the researched area was delineated.According to the method analysis above,four mineralization prediction target areas are delineated.The first metallogenetic prospective area is located in the positive landform of sericitization.The very low frequency F value anomaly map positive abnormally obvious and Ca anomaly in the Ca anomaly is particularly obvious.After the field verification by the surface trench,it belongs to the B target area.The second metallogenetic prospective area is located in positive geomorphology.There is a small area of bare rocks along with fluorite mineralization nearby.A "bimodal" anomaly occurs in the very low frequency F value anomaly map and Ca anomaly in the high Ca anomaly.In the meantime,fluorite ore deposits are found through hole exploration,so the area is classified into Category A target area.The third metallogenetic prospective area stands on a hillside according to the landforms.Very low frequency F value anomaly diagram appears positive high anomaly,Ca abnormal picture appears high abnormality,which indicates that the area has high exploration potential and belongs to class C target area.The 4th metallogenetic prospective area is located in the positive geomorphology of fluorite mineralization.A "bimodal" anomaly occurs in the very low frequency F value anomaly map,and the surface trough has been verified and classified as class B target.