Abstract

This paper presents the analysis of data on patterns observed in the localization of high-grade uranium-tantalum-niobium ores in the Arbarastakh massif of alkaline ultrabasic rocks of Proterozoic age. Processes are characterized that have different effects on the parameters of uranium-tantalumniobium mineralization, as well as their magnetic and radiometric signatures. Uranium-rare metal ores are concentrated in metasomatic rocks of the post-magmatic stage in the massif development, whose formation is related to mantle-derived fluids with iron, phosphorus, sodium, uranium, niobium, tantalum, zirconium, and rare earth elements in the appreciably mobile state. Two types of metasomatic processes can be recognized:

A. Zones of albitization and high radioactivity in the north-south trending fault in the western exo-contact zone of the massif hosting high-grade and large-scale uranium-tantalum-niobium mineralization.

B. Fields of kamaphorites hosting high-grade mineralization controlled by local magnetic and radioactive anomalies of high amplitude in the NWtrending zone at the centre of the intrusion.

Keywords: Siberian platform; Arbarastakh massif; Metallogeny; Fields of high radioactivity and magnetization; Carbonatites; Kamaphorites; Albitites; U-Ta-Nb ores