Perkov Y. The patterns of distribution and formation of chromite ores in the weathering crusts of ultrabasic Middle Bug Area.

On the basis of the conditions established by the formation of morphogenetic types of deposits resolved an important scientific task of establishing patterns of spatial distribution of chromites mineralization of exogenous origin. The dependence of quantitative indicators of exogenous ore formation, which allows allocating the morphogenetic types of deposits and mineralogical-technological types of chromites ore, has been determined in the paper. The influence of erosion and denudation forms of microlandscape surface crust on the distribution of chromite mineralization and changes in quantitative and qualitative indicators has been approved. It's established that the most promising are cloak-like ore occurrence in the near-surface horizons of ocher and nontronite weathering crust of dunite-harzburgite formation. On the basis of a comprehensive study of exogenous chromites ore occurrence and distribution, it's established that the main ore formation factors are favorable combination of erosion and denudation and accumulative weathering regimes. A natural accumulation of ore in the upper parts of residual soils under the erosion impact has been established. Chromites ore of the weathering crust are suitable to alloying of ferrochromium and to manufacture of refractory materials when their content of Cr2O3 is in the range 32-52%, as well as FeOtot. - 15-46%. New genetic type of complex of chromium-nickel deposits is proposed to allocate by associational factor of chromium and nickel mineralization. The typing of exogenous ores has been developed according to established parameters of chemical, mineralogical and grain size. The exploration criteria and resource promise estimate of exoge-nous chromites ore in Middle Bug Area based on mineralization typing has been developed. Prospecting and exploration criteria and factors of chromium mineralization in Middle Bug Area have been substantiated.