Structural-lithological geological-genetic model and mineral composition of Krasnokutskaya rare-metal-titanium placer deposits (Ukraine)

Abstract

The conditions of the occurrence, structure, material composition and controlling factors of Krasnokutsky rare-metal-titanium placer deposit localized in the Miocene sediments of the North-Eastern slope of the Dnieper-Donets basin are investigated. Distinguished lithofacies complexes (alluvial-deltaic, coastal and shallow marine, aeolian) correspond to the Lower (Aquitanian), Middle (Burdigalian) and Upper (Langhian) members of Novopetrovskaya Formation of Miocene. Placer bodies are localized in the littoral marine-coastal complexes of Middle Novopetrovskaya sub-formation. Placerforming process is related to phases of stabilization of the shoreline of the regressive phase of the Sub-Paratetic basin. Main search and forecasting criteria for the identification of promising sites within the Kharkiv-Sumy placer-bearing zone are stabilization of the shoreline in the Middle Novopetrovskaya time simultaneously with development of transverse thereto alluvial-deltaic structures that supply weak mineralized sediments. Also, the deltaic ledge breaking the monotony coastal migration and playing the role of structural-sedimentary traps. The developed digital structural-lithological model of the Krasnokutskoye mineral deposit allows us to offer a set of criteria for comparative evaluation of different placer-bearing areas in order to determine the order of their development. The mineral composition of productive deposits is typical for the placers of the region and for rare-metal-titanium placers as a whole; the increased content of rutile and zircon, which rise the industrial value of placers of this zone, are associated with the influence of crystalline rocks of the Voronezh massif.