New sources of titanium and zirconium minerals from the sand of the Aptian stage based on materials obtained during the 1:200,000 additional site exploration

Abstract

Introduction: In the territory of the Central Black Earth Region, titanium and zirconium placers are valuable and at the same time scarce raw materials. The high content rates of these minerals are noted in the sandy deposits of almost all stratigraphic subdivisions of the geological section. However, the most promising deposits in the Central Black Earth Region where titanium and zirconium placers may be found are the following: sand and clay deposits of the Upper Devonian (Komi superhorizon), Barremian, Aptian, Albian stages of the Lower Cretaceous, the Cenomanian stage of the Upper Cretaceous, and the Neogene. Despite the registration of the placers, such as the Central (Cenomanian stage of the Upper Cretaceous), their development as independent minerals remains unprofitable. Therefore, there is the issue of the associated extraction of titanium and zirconium minerals during the extraction of building, glass, and moulding sand types. This issue was considered during the 1:200,000 additional site exploration works. Methodology: The set tasks required the use of a variety of methods. Field studies, desk constructions of facial maps and sections, and laboratory and technological tests were carried out. Based on a comprehensive analysis of the data obtained, taxa for the regional mineragenic zoning were identified in the following ranks: mineragenic (ore) zones (OZ), regions (OR), and clusters (OC). During the performed work, core samples of more than 50 wells were documented and tested, rocks from over 100 observation points (out-crops and quarries) were described and tested within the Voronezh, Kursk, Lipetsk, and Oryol regions. Samples were prepared and the mineral and chemical composition of about 100 sand samples were studied using precision methods. Results and discussion: Sand deposits of the Aptian stage with good potential to become a raw material for glass were examined for the content of heavy fraction minerals. The heavy fraction is represented by zircon, leucoxene, ilmenite association with small contents of disthene, rutile, staurolite, and tourmaline. The placers were formed due to rewashing and sizing of silt sand material in continental and coastal-marine environment. Multiple rewashing and sizing of sand is one of the main conditions for the accumulation of heavy fraction minerals. The titanium and zirconium placers are distant transport placers. The transport sources were for them were the more mature Paleozoic-Mesozoic sedimentary rocks of the Voronezh anteclise. Conclusions: As a result of the 1:200,000 additional site exploration, for the first time, ore clusters were identified and registered, for which the predicted resources of the P 3 category were calculated for titanium, zirconium, and glass sand.