The key section of the Aseri, Lasnamägi and Uhaku Regional Stages (Middle Ordovician) on the Volkhov River is formed by the Duboviki, Porogi-Valim and Vel’sy formations. The Duboviki Formation (Aseri RS) corresponds to silt-argillaceous limestone unit with Echinosphaerites aurantim infra Hecker. It is subdivided into Kavra, Mel’nitsa, Suosaari and Jhikharevo members. The new Porogi-Valim Formation consists of Porogi Subformation (the top of the Aseri RS and Lasnamägi RS) and Valim Subformation (lower part of the Uhaku RS). The PorogiValim Formation shows decreasing carbonate content towards the top and is presented by intercalation of hard limestone units (0.4–1.2 m thick) and silt-argillaceous limestone units (0.16–2.4 м). The hard limestones dominate in the Porogi Subformation, the silt-argillaceous ones – in the Valim Subformation. The Vel’sy Formation (upper part of the Uhaku R. Stage) is formed by intercalation of marls and highly silt-argillaceous limestones. A common feature of the Ukhaku RS of the Volkhov River is a combination of a high silt-argillaceous background (limestones/marls) with frequent interlayers of pure bioclastic grainstones (tempestites). The lower boundaries of the formations and subformations are marked by mineralized hardgrounds and their groups, which can be traced from the Volkhov River to western Estonia.

The paper describes the geological structure of the copper sandstone deposits of the Perm, Vyatka-Kama, Bashkir, and Orenburg ore regions in the eastern part of the Russian Platform and the Western Urals. It is noted that copper mineralization within a single area can simultaneously affect sediments formed in marine, lagoonal-marine, and continental conditions. Its local movement upsection is also observed. The rejuvenation of copper sandstones is also recorded regionally in the southwestern direction along the circular blocks of the Sverdlovsk radial-concentric structure with a diameter of more than 2400 km, identified from structural, tectonic, and geomorphological data. Mineralization is heterogeneous both in section and along strike. Copper ores are developed inversely to the rocks gypsification. The highest copper contents are confined to the lower parts of productive horizons. It is concluded that copper sandstone deposits are a possible result of vertical migration of deep hydrothermal solutions along neotectonic faults during the Sverdlovsk megastructure formation in the Alpine phase of tectogenesis. It is recommended to continue research to identify and map its sectorial blocks and study associated mineral deposits.

The article shows the results of mineralogical and petrographic studies of diamond-bearing Late Triassic tuffs, tuff gritstones, and tuff sandstones of the Bulkur member, differing in the amount of volcanogenic material into tuffs, orthoand paratuffites. The tuffs were formed as a result of phreatomagmatic eruptions during the Carnian in the Primorsky deep faults zone. Tuffs and orthotuffites contain outstanding pyrope concentrations with a small amount of diamond-bearing dunite-harzburgite parageneses and a high content of diamondbearing eclogites. For the first time, information about the MIC kelyphitic rims and widespread hypergene mineralization in the rocks is given. The presence of a considerable number of garnet megacrystals suggests the possible discovery of large diamond crystals, which will have a positive effect on the raw materials cost.

We propose a geochemical classification of ore-hosting sediments, which reflects the total content of components in rocks that influence redox processes. A geochemical type is understood as a group of rocks characterized by a certain, different from others, value of the redox potential of an aqueous solution in equilibrium with the rock. The classification can be used to predict hydrogenic uranium mineralization (sandstone type), as it enables to assess the potential ore content of ore-controlling zones of bed oxidation.

The authors assess the commercial uranium prospects in the Yuzhny Island, Novaya Zemlya archipelago and characterize the main uranium ore targets with resource assessment. It is possible to identify highly productive uranium deposits of the black shale (Ronneburg) type here. The authors give recommendations for further works.

The main metallogenic potential of the Nechersk uplift and its Riphean framing is formed by deposits and ore occurrences of uranium, hard rock and placer gold, lead, zinc, rare metals, and rare earth elements, which form the mineral resource base of Northern Transbaikalia. The new geological and metallogenic data obtained for the area under consideration determine the mineral distribution patterns, main mineralization types, and substantiate the prospects for identifying ore targets in known and new geological settings.

The growing demand for lithium is driven by the transition to renewable energy sources. In this regard, it is relevant to study new deposits and technologies for lithium mining in order to ensure a stable supply to the market and support environmentally sustainable production. This article studies the migration paths of lithium-bearing brines and the mechanism of clays formation with a high lithium content: hectorite, illite, and smectite. A generalized model for the formation of the Tucker Pass caldera-type lithium-bearing clay deposits in North America is described. Particular attention is paid to the role of hydrothermal fluids as a potential additional source of lithium “supply” to the caldera basin. Key criteria characterizing commercial accumulations of lithium of this type are listed.

The Russian Geological Library was founded in 1882 and is the first geological library in Russia. Over almost a century and a half of activity, the institution’s collection has been constantly replenished, including the publications transfer from other libraries. The storage units that came as a result of the German library collections transfer in the post-war years stand apart separate in this series. The article examines a brief history of Russian and foreign libraries that have replenished the foreign language books collection of the Russian Geological Library and provides their ex libris.