Grain-size and material composition of quartz sands of the Devitsky and Volchinsky Aptian formations in the north-east of the Voronezh anteclise

Abstract

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Introduction: quartz glass, sands in the Central Black Earth region are an extremely scarce type of mineral raw materials, the deposits of which have not yet been discovered, although there are prerequisites for this. They are associated with Aptian deposits, which are quite widely developed in the northeast of the Voronezh anteclise (VA) within the territory of the Lipetsk region. There are many manifestations of quartz sands, but they relate only to construction differences, a number of deposits of which have been explored and exploited. But they do not correspond in quality to more valuable glass ones. At the same time, the latter are present in separate intervals of Aptian sections. Therefore, the purpose of this article was to assess the possibilities of using the sands in question as glass raw materials.

Methodology: in the process of research, the results of grain-size, mineralogical and chemical analyzes of 187 samples from 14 wells were analyzed. Based on the obtained data, diagrams of distribution of grain-size fractions and chemical composition of the considered sands were constructed and analyzed to identify the possibilities of their use for practical purposes.

Research results: lithological analysis of the Aptian deposits of the north-eastern part of the VA showed that the quartz sands of the Devitsky and Volchinsky suites form geologic bodies of the same age, formed under different facies conditions. The first were formed in coastal-marine, the second in shallow-marine environments. The study with the help of granulometric, mineralogical and chemical analyzes of Aptian rocks of predicted promising areas for construction raw materials made it possible to identify the possibilities of using quartz sands also as glass. The glass sands of the coastal-marine zone, developed in the south of the territory under consideration, are of different grain sizes, have multidirectional oblique bedding. They contain an increased amount of fraction over 0.8 mm in the lower part and a noticeable amount of silt-clay impurity in the upper parts of the sections. Shallow-marine quartz sands are on average finer-grained than coastal-marine sands and include increased amounts of heavy fraction.

Conclusion: the study of grain-size and material compositions of a large number of samples of quartz sands of the Devitsky suite showed that with standard enrichment it is possible to obtain grades of glass sands C, BC, OBS. Higher-quality sands of the Volchinsky formation can be used to produce higher-grade OVS and OVS raw materials.