Laws of Formation and Criteria for Predicting Nickel Content in Weathering Crusts of East Kazakhstan

Abstract

The article considers from the theoretical point of new global tectonics the geological conditions of formation, peculiar features of material composition, and criteria for predicting deposits of nickeliferous weathering crusts of east Kazakhstan. According to geotectonic zoning, this territory includes geological structures of the Big Altai (BA), which is part of the central Asian mobile belt. The ore-controlling role is assigned to the area of global interaction of the Kazakhstan and Siberian paleocontinents during the stage of the Hercynian collision (í‘₁-í‘₃) followed by the formation of the Zaisan suture zone, the structure of which is represented by the Charsky-Gornostaevsky ophiolite belt (suture stitch). During the Hercynian cycle of tectogenesis, main gold fields of the regions appeared in the Zaisan suture (gold-quartz, gold-sulphide, goldlistvenite, etc.) in a collision situation, controlled by a system of deep faults of the crust and mantle type. In similar tectonic environment, large stockwork gold deposits were formed in Rudny Altai, north Kazakhstan, and other regions. During the Cimmerian cycle, the residual weathering crust deposits of Au, Ti-Zr, Ni-Co were formed in the region of continental rifting. The article emphasizes the spatial association of silicate cobalt-nickel deposits to the outputs of serpentinized ultrabasites of the Charsky- Gornostaevsky belt and provides a characteristic of the geological structure and material composition of nickel content in ores of the Belogorskoye and Gornostaevskoye standard deposits. Expansion of prospects depends on the possibility of growth of reserves of cobalt and nickel ores on the flanks and deep horizons of the known ore fields and search for buried deposits in prospective areas determined by geological and geophysical studies.