Geological Characteristics And Prediction Evaluation Of Elimutai Fluorite Deposit In Linxi,Inner Mongolia

The Linxi area of Inner Mongolia is located in the southern section of the Greater Xing'an Mountains,and the geotectonic location is in the eastern section of the Late Paleozoic orogenic belt(CAOB)in Central Asia.The geological conditions in the area are complex,especially in the frequent Mesozoic tectonic-magmatic activities,which provides favorable geological conditions for the mineralization of nonferrous metals,polymetallic deposits and fluorite deposit.Based on the Elimutai fluorite mine in Linxi County as the research object,this article summarizes the geological and geochemical characteristics of the fluorite deposit through data collection,field geological survey and comprehensive indoor research.Through the comparative analysis of the metallogenic characteristics of the Hanpaozi fluorite deposit with the combination of the comprehensive geophysical and chemical remote research,the resource potential of the deep Elimuta mining area is predicted and evaluated.The research has achieved the following results and understandings:1.Orebody of Elimutai fluorite mine is strictly controlled by NE-NNE fault structure.The orebody is vein-like,lentil-lens-like,the occurrence is consistent with the ore-controlling fault,and the alteration zone extends from north to south> 1000 m.Fluorite is mostly transparent-semitransparent lavender,green-light green and colorless with self-shaped,semi-self-shaped,and other granular structures.Massive,breccia-shaped,and banded structures are well developed.The combination of ores and minerals mainly covers fluorite,quartz,opal and kaolin.The metallogenic stage is divided into early stage-fluorite-quartz stage and late stage-quartz-fluorite stage.2.Geochemical studies of rare earth elements reveal that fluorite is enriched in light rare earth(LREE)in early stage and heavy rare earth(HREE)in late stage.The vertical variation characteristics of fluorite rare earth elements are consistent in the early and late stages;?Eu reactive ore-forming fluid changes from reducing environment to oxidizing environment with the decrease of depth.3.Research on ore-forming fluid inclusions shows that the inclusions are mainly liquid-rich primary fluid inclusions,which are distributed in groups.Fluorite has a uniform temperature of 170 ~ 240? and a salinity of 0.6 ~ 2.6% Nacleqv,belonging to a hydrothermal deposit of medium-low temperature and low salinity.4.Based on the comparative analysis of the metallogenic geological and geochemical characteristics of Hanpaozi fluorite ore and Elimutai fluorite ore,it is believed that the study area is affected by the post-mineralization faults,the northern and southern sections of Hanpaozi mining area are relatively uplifted,and the middle section of Hanpaozi mining area and Elimutai mining area are relatively sunken and buried deeper.There are also well-developed ore bodies below-100 ~-150 m and-250 m in Elimutai mining area as well as in Hanpaozi mining area.5.Combined with geophysical,geochemical and remote comprehensive survey results,it is predicted that it boasts good resource potential and promising prospecting prospect in the deep part of Elimutai fluorite mine.