Geological Characteristics And Metallogenic Regularities Of The Kyanite Deposits In China

Kyanite（Al₂[SiO₄]O）is one of the important ore minerals of the kyanite deposit,and it is also a typical metamorphic mineral in crystalline schist.In the aluminum-rich rock,it is produced under medium pressure low temperature metamorphism.In addition,kyanite is also produced in certain high pressure metamorphic belts.The kyanite is widely used in the kiln industry of metallurgy,building materials and chemicals because of its high temperature resistance,corrosion resistance and volume expansion during calcination.Most kyanite deposits in China are regional metamorphic deposit.This type of deposit exists in the active tectonics belt.The main ore-bearing strata are middle-late Proterozoic.The ore body is layered or generally layered,and few is lenticular.The ore-bearing rocks are mainly quartzites and schists.The ore types are mainly kyanite quartzite,kyanite（mica）quartz schist and kyanite.The mineral composition are mainly kyanite,quartz and muscovite.Through the study of the characteristics of the kyanite deposit,it is found that the tectonic setting plays a controlling role in the temporal and spatial distribution of the kyanite deposit in China.The main mineralization of the kyanite deposit is regional metamorphism mineralization and thermal contact metamorphism,besides,few are hydrothermal erosion,dynamic metamorphism and mixed lithification mineralization.With the increase of metamorphic temperature,kyanite will recombine to form andalusite and sillimanite.Therefore,the metallogenic area of kyanite is not only the prospecting area of kyanite,but also the ore formation of andalusite and sillimanite.Combined with the distribution of kyanite deposits,five ore-forming zones and prospects are divided:the eastern Qinling kyanite metallogenic area,the Jilin-Heilongjiang Precambrian block kyanite metallogenic area,the North China ancient continental core area kyanite metallogenic area,the North China platform north edge kyanite metallogenic area and the Sulu high pressure metamorphic zone kyanite metallogenic area.The geological work of kyanite in China started late and the input is small,and most kyanite deposits are low-grade small and medium-sized deposits,so in the above-mentioned metallogenic zone,carry out the work of kyanite,andalusite and sillimanite is conducive to comprehensively grasp the current situation of Chinese mineral resources.