Prospect for expansion and replenishment of rare metal resources and reserves in Eastern Kazakhstan

The main rare metal-bearing structures in Eastern Kazakhstan are granitoid belts formed in the Hercynian cycle of tectogenesis in the post-collisional (orogenic) geodynamic environment of the Permian time and confined to the continental blocks of siallitic high-level. The geotectonic position of the Kalba–Narym rare metal granitoid belt in the geological structure of the Greater Altai is considered. The known rare-metal pegmatite deposits (Ta, Nb, Be, Li, etc.) are spatially and genetically related to Kalba granites (P1). The richest ore-bearing are granite massifs formed in the mobile tectonic environment and under unbalanced P–T conditions. The distribution of rare alkalis in granitoids of the Hercynian evolutionary series is given. The forecast estimate of prospects is associated with the study of hidden granite massifs on the northwestern flank of the belt, identified based on the geological and geophysical data. The forecasting criteria are the intensive alteration of the above-intrusive zone (granitization, greisenization, silicification), direct signs of tin–tungsten mineralization on ground surface, identification of ongonite-like dikes and rare metal minerals in metasomatites from the results of electron microscopy. The estimation of the prospects of nontraditional tin–lithium–tantalum mineralization associated with albitized and greisenized granites is given. It is recommended to undertake deep mineralogical mapping of the closed reserved areas. The further geological exploration should be aimed at expansion of mineral resources and reserves for rare metal production.The study was supported by the Committee of Science of the Ministry of Education and Science of the Republic of Kazakhstan, Contract No. 120 dated 1 June 2020, Registration No. 0120RK00135, and Grant IRN AR08856325.