Scandium prospects in the Yakutian Diamond Province

Abstract

Prerequisites and signs of scandium deposits in the ancient weathering crusts and in the oxidation zones in the Upper Paleozoic strata in West Yakutia are defined and substantiated. The prerequisites include: the presence of scandium sources—basic rocks, kimberlites and carbonatites; the spread of the ancient formation and ground oxidation which conditions migration of scandium; the presence of weathering crusts of the Carboniferous and Mesozoic ages, with alkaline and adsorptive barriers which concentrate scandium; good prospecting at depths up to 100 m. These prerequisites govern the relevance of the research as there is a possibility of scandium recovery from ore by in-situ leaching. Ancient oxidation in the strata and in the fractures in the gray-colored Сarboniferous–Permian formations and in the underlying weathering crusts is detected in the Ulakhan-Kurung-Yuryakh area of the Malaya Botuoba region in the Yakutian Diamond Province. Ancient epigenetic processes are confirmed by zonal limonitization and clarification of primary gray-colored rocks, and by redistribution of uranium, vanadium and gallium with the increased background contents of V and Sc. The X-ray fluorescence analyses performed in the Malaya Botuoba, Middle Markha and Ygyatta diamond-bearing regions revealed areal concentrations and promising scandium ore occurrences in the ancient weathering crusts and in the Late Paleozoic formations. In the weathering crust, in Suldyukar kimberlites, scandium concentrations exceed 100 ppm and feature high (up to 0,n%) contents of V, Co, Ni, La and Ce. The outstanding concentrations of scandium are found in the Triassic–Jurassic Dyakhtar clayey rocks representing a derivative weathering crust in the Nakyn diamondiferous field.