ILMENITE FROM THE LOWER CRETACEOUS CONTINENTAL DEPOSITS OF THE ANDRIYIVSKY PLACER DEPOSIT OF TITANIUM ORES

Abstract

A brief description of the ore-bearing capacity of the Andriyivksky placer deposit of titanium ores, which is located within the Korsun- Novomyrhorod pluton of the Ingul megablock of the Ukrainian Shield, is given. The productive deposits of the Andriyivksky deposit are Aptian-Lower Albian alluvial-deluvial formations, which are represented by kaolinite sandy and redeposited kaolins, partly Quaternary alluvial sands (in the northern part) and, sometimes, coastal-marine sands of the Upper Albian. Lower Cretaceous continental deposits lie in a tectonic-erosional paleovalley in the weathering crust of crystalline basement rocks. According to the chemical analysis of ilmenite, the lateral distribution of this mineral with different oxide contents (TiO2, FeO, Fe2O3, FeO/Fe2O3, V2O5, P2O5, Cr2O3) in the Lower Cretaceous continental deposits of the Andriyivksky deposit was investigated. It has been established that the chemical composition and spatial distribution of the average content of ilmenite with different oxide contents is determined by the peculiarities of mineral formation in crystalline rocks of the basement, hypergenic transformations of the mineral in different zones of the weathering crust, and the transformation of the mineral during sedimentogenesis and diagenesis of sediments. Based on the analysis of the results of chemical analysis of ilmenite, it was found that the degree of alteration of ilmenite in the Andriyivsky deposit is insignificant. It should be noted that the degree of alteration of ilmenite in sand deposits is slightly higher than in redeposited kaolins. This is due to the more intense and prolonged transformation of ilmenite in sand formations compared to redeposited kaolins. In general, in Lower Cretaceous deposits, the TiO2 content in ilmenite is 44.71–56.21%; the Cr2O3 content is 0.017–0.027; the FeO/Fe2O3 ratio is 1.11–4.15.This indicates that ilmenite in Lower Cretaceous deposits is slightly altered and of high quality. The direction and strength of correlation relationships between oxides in ilmenite were investigated. It was found that in ilmenite from sand deposits and redeposited kaolins, there is a strong inverse correlation between the content of FeO and Fe2O3; P2O5 and V2O5.