Background. In order to achieve a high efficiency in the development of deep-seated deposits, mining sciences are required to optimize the parameters of mining operations, equipment and technology, to study and develop the principles of a rational combination of various resource-saving, low-waste and resource-reproducing technological processes, above all, providing the widespread use of automated planning systems and methods for managing the extraction of minerals.

Aim. To analyse the state and main directions in the development of the Earth’s interior resources.

Materials and methods. The research was carried out on the basis of a comprehensive analysis of scientific publications, reports and archive materials on the development of mineral resources.

Results. A scheme describing the formation of a consolidated natural-technogenic massif in the Earth’s interior and a technological diagram of the movement of mineral-raw material flows are presented. A conclusion is made that it is expedient to create the technologies for the purposeful formation of deposits on the basis of the principle of geotechnological continuation of the formation of useful components by artificial methods using natural forces to transform deposits to a state that is maximally acceptable for subsequent development. Such technologies should provide the creation of conditions in the massif for the spatial separation of useful components, changes in the physical properties of rocks, the conditions of occurrence of minerals and, on this basis, increasing the efficiency of traditional and new ways of developing deposits.

Conclusion. The use of these technologies will allow the resource base to be expanded by increasing the concentration of useful components in the Earth’s interior and involving poor deposits and ore occurrences in the development; to increase the value of deposits due to associated components obtained in the processes of material transformation of ores; to reduce the depth of mining operations due to the formation of technogenic deposits on geochemical barriers near the Earth’s surface; to reduce the development time of deposits; and to reduce the technogenic load on the environment. The creation of such technologies will require a deep integration of the efforts of geologists, geochemists, geophysicists, ecologists and miners.

Background. New information was obtained on brown coal occurrences in the northern part of the Yenisei-Khatanga trough (Lake Taimyr area). This region continues to attract the attention of geologists and oil producers due to its established oil and gas potential.

Aim. To study the lithological features of rocks and material-petrographic composition of coals from a new promising area of the Yenisei-Khatanga trough in northern Russia.

Materials and methods. A set of geological, lithological, and petrographic research methods was used to study a series of samples of coals and host rocks. Measurements were carried out on a QDI-302 Craic Spectrophotometer microscope with a 50× objective lens according to the standard methodology ISO 7404-5 in reflected polarised light using a Spinel standard (Ro = 0.426%) in oil immersion. X-ray fluorescence analysis was performed using a Respect device with an energy dispersive spectrometer without vacuum, having an X-ray tube with a silver anode (registration of elements only from K to U). Anode voltage — 30 kV. Current — 0.3 mA. Exposure time (τ) — 300 s. Y axis — intensity of characteristic lines, rel. units

Results. The lithological features of the studied samples were elucidated, and the material-petrographic composition of the coals was studied. In the spore-pollen assemblage from the studied deposits, the dominant associations were determined by the predominance of two-bag pollen of Disaccites (Pinaceae) conifers. On this basis, the age of the Begichevskaya Formation rocks was established as belonging to the Albian and Cenomanian stages of the Lower-Middle Cretaceous.

Conclusion. The degree of variability of coals was estimated; their grades (technological groups) and the trace element composition of ash were determined. The reflection values of vitrinites were measured in order to clarify the stage of changes in brown coals and obtain the quantitative characteristics of their quality. The reflection values of vitrinites (Ro) are from 0.32 to 0.52%, which corresponds to the stages of brown coal changes, technological groups 1B—3B.

Background. Volcanogenic massive sulphide deposits (VMS) are the most important sources of Cu and Zn; they account for a large share of the world production of Pb, Ag, Au, Se, Te, Bi and Sb, as well as small amounts of many other metals. The polymetallic VMS deposits of economic value of varying degrees are known in the rocks of the Los Pasos Cretaceous Formation, Cuba.

Aim. To show the potential of the Cretaceous volcanic deposits of Central Cuba for gold, silver, copper, zinc and lead deposit prospecting.

Materials and methods. The study characterises the San Fernando, Independencia, Antonio, Los Cerros VMS deposits and the Boca del Toro and El Sol ore occurrences located in the Los Pasos Formation. The similarities and differences in the mineral and elemental composition and structures of the ores of these objects are described, which underlie the assessment of their economic importance.

Results. The latitudinal zoning of VMS and noble metal mineralisation of the Central Cuban ore region is outlined. In the west, copper-VMS deposits with accompanying gold ore objects prevail. In the east, copper-zinc VMS deposits with barite and gold-silver objects are widespread.

Conclusions. It is necessary to assume the different erosional sections corresponding to the blocks of the Cretaceous volcanic arc of Central Cuba, which is larger in the west and smaller in the east. Proceeding from the presence of veinlet gold ores, their confinement to tectonic zones and the lack of correlation between noble and chalcophile metals at the San Fernando deposit, as well as significantly different gold-silver ratios in the considered ore objects, it could be assumed that some of the gold-silver ores were formed after VMS. The obtained Au/Ag ratios are close to the ores of the high sulphidation type (high sulphide ores) from similar ore regions of Venezuela and the Kur-il island arc. In this regard, one can expect hidden gold deposits in the west and gold-silver deposits in the east of the studied area.

Background. The South Turgay basin has been extensively studied using geological and geophysical methods. To date, the discovery of large oil and gas deposits in its structural traps seems impossible. The deposits, which have been under development for a long time, demonstrate the trend towards depletion. Therefore, a search and exploration of non-anticlinal traps is becoming an important source of hydrocarbon reserves.

Aim. To identify zones of non-anticlinal reservoirs and traps.

Materials and methods. On the basis of three main criteria for predicting the development of nonanticlinal traps (stratigraphic, lithofacies and structural-tectonic), this paper presents the forecast zones for the development of non-anticlinal traps with oil and gas potential, taking into account the facies diagnostics of the deposits.

Results. The traps of regional pinching-out, as well as possible traps of erosion-accumulative and accumulative subgroups, are predominantly developed in the trough. The traps of the regional pinch-out subgroup are most widespread in the Aryskum and Bosingen graben synclines. The traps of the accumulative subgroup are predicted mainly in the Bosingen and Akshabulak graben synclines.

Conclusions. According to the obtained results, the South Turgay Basin possesses a significant oil and gas potential in non-anticlinal traps. Lithological reservoirs with thick and widespread mudstones confined to the Jurassic deposits are of particular interest.

Introduction. To date, no unified well-established concepts have been developed regarding the oil and gas geological zoning of the Laptev Sea shelf, as well as other seas of the Eastern Arctic. Different groups of researchers define this region either as an independently promising oil and gas region [7, 8], or as a potential oil and gas basin [1].

Aim. To construct spatio-temporal digital models of sedimentary basins and hydrocarbon systems for the main horizons of oil and gas source rocks. A detailed analysis of information on oil and gas content, the gas chemical study of sediments, the characteristics of the component composition and thermal regime of the Laptev sea shelf water area raises the question on the conditions for the formation and evolution of oil and gas source strata within the studied promising oil and gas province. The conducted research made it possible to study the regional trends in oil and gas content, the features of the sedimentary cover formation and the development of hydrocarbon systems in the area under study.

Materials and methods. The materials of production reports obtained for individual large objects in the water area were the source of initial information. The basin analysis was based on a model developed by Equinor specialists (Somme et al., 2018) [14—17], covering the time period from the Triassic to Paleogene inclusive and taking into account the plate-tectonic reconstructions. The resulting model included four main sedimentary complexes: pre-Aptian, Apt-Upper Cretaceous, Paleogene, and Neogene-Quaternary.

Results. The calculation of numerical models was carried out in two versions with different types of kerogen from the oil and gas source strata corresponding to humic and sapropel organic matter. The results obtained indicated that the key factor controlling the development of hydrocarbon systems was the sinking rate of the basins and the thickness of formed overburden complexes, as well as the geothermal field of the Laptev Sea.

Conclusion. The analysis of the results obtained allowed the most promising research objects to be identified. The main foci of hydrocarbon generation in the Paleogene and Neogene complexes and the areas of the most probable accumulation were determined. Significant hydrocarbon potential is expected in the Paleogene clinoforms of the Eastern Arctic.

Background. The Volga river channel with rapids limiting the navigation parameters of large-tonnage vessels between the cities of Gorodets and Nizhniy Novgorod is considered in the structure of the Unified deep-water system of waterways of the European part of the Russian Federation.

Aim. To justify the need to develop design solutions providing sustainable navigation in the limiting river section under study during the entire navigation period.

Materials and methods. An analysis of engineering-geological and geoecological conditions of the region, including a limiting channel section of the Volga.

Results. The engineering-geological and geoecological conditions of the region were characterized. A brief description of individual project proposals, including two priority construction projects, a low-pressure hydroelectric unit and a ship canal, was provided with a comparative assessment of natural and man-made factors arising during their implementation.

Conclusion. The implementation of the project for the construction of the Volgo-Don 2 canal should be an important stage in the development of the Unified deep-water system of waterways in the European part of the Russian Federation. It will replenish the Don River from the Volga in order to improve navigation conditions, land irrigation, water supply to settlements, and power generation.

Background. In this article, we investigate an outcrop of the Lower Jurassic limestones of the Eskiorda suite located on the northern slope of the Bodrak River basin in the south-western Crimea.

Aim. The outcrop under study is mentioned in the majority of monographs devoted to the geology of the Crimean Mountains. Although the palaeontology of this assemblage has been sufficiently studied, its lithological aspects require elucidation. We carried out a series of lithological studies to identify the composition, structure and formation conditions of this limestone assemblage.

Materials and methods. A macroscopic study of the outcrop was conducted followed by a detailed lithological study of collected limestone samples using a polarising microscope.

Results. The conducted microscopic analysis revealed three structural types: organogenic-detrital, detrital and oolitic-organogenic-detrital limestones. The dominant component in the composition was fragments of echinoderms, mainly crinoids. Among other components were — in descending order — brachiopods, gastropods, foraminifera, remains of green algae, sponges, ostracods, ammonites and radiolarians, whose total content did not exceed 10%. Cinoid fragments were round to a various degree. The limestone fragments (intraclasts) were characterised by organogenic-clastic and pelitomorphic structures with an organogenic sludge, occasionally containing fine-sandy and silty quartz admixtures. Oolitic-organogenic-detrital limestones were almost entirely composed of crinoid fragments, some of which represented oolith cores. A specific feature of the limestones under study is their significant hardness resulting from the cementation of the structural components predominantly with crustification cement of several generations.

Conclusions. The obtained results allowed us to draw conclusions about the formation conditions of the studied rocks. The limestones were formed in shallow water under the action of waves on the sediment in zones of constant currents. The hydrodynamic action on the sediment led to the formation of intraclasts. The early lithification of the sediment contributed to the formation of a hard seabed, on which subsequent generations of echinoderms settled, lived and died, forming an accumulative carbonate body.

The article presents the biography of O.A. Denisova (1893—1972), one of the first Russian female geologists involved in practical geology. In 1918, she graduated from the Natural Department of the Faculty of Physics and Mathematics of Moscow Higher Women’s Courses. During her studies, she participated in field research in the Moscow Region, on Volkhov and Vychegda rivers under the guidance of A.B. Missuna. In 1923, she graduated from Moscow State University with a degree in geology. Since 1918, O.A. Denisova had worked as a researcher in the Moscow branch of the Geological Committee, since 1920 as a geologist in the Geological Department of the Special Commission for the Study of the Kursk Magnetic Anomaly. Later she was engaged in the study of deposits of building materials and hydrogeological surveys. O.A. Denisova began her activity under the supervision of A.D. Arkhangelsky. The article contains her previously unpublished memories about this famous geologist. O.A. Denisova taught geology and hydrogeology at universities and technical schools in Moscow. In 1936 O.A. Denisova was awarded the degree of Candidate of Geological and Mineralogical Sciences without defending a thesis, and in 1946 the All-Union Certification Commission approved her with the academic rank of Associate Professor at the Department of Geology. O.A. Denisova was awarded the medal “For Valiant Labour during the Great Patriotic War of 1941— 1945” (1946) and “In memory of the 800th anniversary of Moscow” (1948). The collections of rocks and minerals collected by O.A. Denisova during field work in the Kursk and Belgorod regions, are stored in the State Geological Museum named after V.I. Vernadsky of RAS.

Specialists of the Sergo Ordzhonikidze Russian State University for Geological Prospecting (MGRI), which had been training gemologists for many years, conducted an interesting and substantial study devoted to a non-traditional use of cassiterite, a mineral known to man for millennia. The monograph2 under review discusses various aspects of the use of cassiterite, as well as its accompanying minerals, for producing jewelry, collection and ornamental materials. Given the increasing popularity of natural minerals in recent decades, there is a growth of interest among collectors and manufacturers in non-traditional semi-precious stone raw materials and their use in the jewelry industry. The world trade in this area is significant and continues to demonstrate an increasing trend. In this regard, the work of D.A. Petrochenkov devoted to jewelry and ornamental cassiterites seems to be highly relevant. For the first time in world practice, the monograph comprehensively covers questions concerning cassiterite and its application, thus contributing to popularization of cassiterite jewelry and craftsmanship and laying the foundation for a new direction in the semi-precious stone industry. The author of the monograph critically reviewed the results of previous studies on the mineral and chemical composition of cassiterite and added an extensive set of his own analytical methods. The gemological and technological characteristics of cassiterite minerals were given, along with recommendations on their rational search, use and quality improvement. In term of ecological parameters, it was shown that the content of carcinogenic and radioactive elements in jewelry cassiterites does not exceed the background values. The market conditions were described, and recommendations on the organization of mining and geological work in this sphere were presented.