Vertical Zoning Characteristics And Prediction Of Fluorite Deposits In Linxi Region, Inner Mongolia

There are many fluorite deposits in Linxi, Inner Mongolia. It locates in theeastern section of the Central Asian Orogenic belt, which locates between the GreaterHinggan Mountains microplate and the Sino-Korean plate. The emergence stratumsinclude mainly the Permian and Jurassic and wide Yanshanian intrusive granite. Thetypical fluorite deposits in this region were selcted for the study in this paper. Thevertical zonality of the morphological characteristics of mineralized veins and thecharacteristics of mineral assemblages, ore texture and structure, wall rock alteration,geochemistry and fluid inclusions are summarized systematically based on fieldinvestigation and laboratory analysis. The vertical zonality pattern of fluorite depositwas established and applied in the calculation and estimating of hidden andsemi-hidden fluorite deposits. The main results include::1. The morphological characteristics of fluorite deposits in the region, ore textureand structure, mineral assemblages, wall rock alteration, and other geological featuresare described and the mineralization stages of fluorite deposits are divided. Thevertical zoning characteristics of mineralized veins are summed up by contrasting thevertical changing rules of the characteristics of fluorite deposits.2. The analysis result of trace elements shows that the content of Li, Rb, Ba, Sb,Pb, Cs elements decreased from shallow to middle part of fluorite deposit, while theelements of Sc, V, Cr, Co, Ni, Y, W, Sr were opposite.3. The analysis result of REE indicates that the content of REE raised fromshallow to deep of the fluorite deposit. However, it has the highest content of REE inthe top of fluorite deposit. The fluorite enrichs in HREE and it shows that the fluoriteformed later than quartz. Fluorite taken from deep part of deposits enriched in HREEthan that taken from shallow part of fluorite deposits and it shows that the formerformed later than the latter.4. The analysis of temperature measurement and laser in situ Ramanspectroscopy of fluid inclusions indicate that the petrographic features, uniformtemperature and salinity of fluid inclusions have significant vertical zonality. From shallow to deep of fluorite deposits, the size of inclusions totally become larger, butthe top part of fluorite deposits appears abnormal phenomenon, the size of which isthe smallest ones, while the gas-liquid ratio shows the opposite changing trendency.Uniform temperature was gradually decreased, but the salinity decreased and thenincreased. Density, pressure, and gas-liquid components of fluid inclusions have notobvious vertical zonality.5. On the basis of systematically summaring the vertical zoning characteristics ofmineralized veins, geochemistry and fluid inclusions, the vertical zoning pattern offluorite deposit was established. Combining the fruit of the geological survey,geophysical exploration, geochemical exploration and remote sensing interpretation,the vertical zoning pattern of fluorite deposit was used to judge the spatial position ofmineralized outcrops and mineralized veins exposed by exploration engineerings inSaiboluogou, Elimutai and Paodaogou fluorite deposits, and estimate themetallogenetic potentiality of the deep of fluorite deposits.