In the Arctic Ocean, the Amerasia and Eurasia basins are recognized. They are separated by the Lomonosov Ridge. In the southern part of the Amerasia Basin is the Canada Basin with Cretaceous oceanic and transitional crust. The Alpha-Mendeleev Rise and its associated deep-water basins (Podvodnikov, Makarov, Toll, Nautilus, and Stefansson) lie to the north of the Canada Basin. The Alpha-Mendeleev Rise and associated basins contain varying amounts of altered continental crust. Their major construction period was about 125–90 Ma. We discuss three models for formation of the Canadian Basin. Model-1: the entire Amerasia Basin with oceanic and transitional crust was formed first (before 125 Ma). This was followed by the Alpha-Mendeleev Rise region which formed as a volcanic formation on earlier oceanic crust (125–90 Ma). Model-2: the Canada Basin formed first (before 125 Ma). The Alpha-Mendeleev Rise region and associated basin then formed via continental crustal extension and magmatism (125–90 Ma). Model-3: the Alpha-Mendeleev uplift region and associated basins formed above a mantle plume (125–100 Ma). Subsequently, along one of the branches of continental rifting, spreading formed transitional and oceanic crust and the Canada Basin was formed (100–70 Ma). We find Model-1 to be the least probable, since it is now proven that the Alpha-Mendeleev Rise is underlain by continental crust. Models-2 and -3 are both possible. According to these models, the Canada Basin formed as a back-arc basin of the Pacific subduction zone.

   Zonal metamorphism is widely manifested within the North Taimyr tectonic zone, composed mainly of rocks from the continental slope and the foot of the Kara continent passive margin. To explain the observed zonal metamorphism features, numerical geodynamic modeling was carried out, reproducing the continental collision of the Kara and Siberian continents in the late Paleozoic. It is shown that the modeling P–T conditions dynamics of continental crust rocks (P–T–t trends) corresponds well to the observed metamorphic zonality thermodynamic parameters. It has been proposed a geodynamic scheme, according to which the formation of metamorphic zonality in Northwestern Taimyr occurred on the descending branch of the P–T–t metamorphism trend. Such metamorphism took place at the final stage of the collision that formed the North Taimyr tectonic zone.

   The Cenomanian ammonite “Ammonites Cabardinense”, first described from the Mineralnye Vody region of Kabardino-Balkaria and cited from several localities in the Caucasus and Transcaucasia, is discussed. The location of the holotype is unknown, and a re-examination of the “Sharpeiceras cabardinense” from Transcaucasia has shown that it belongs to the genus Mantelliceras. 

   2D and 3D models of geological structures of Subandino thrust-fold beld was done with using structural-kinematic modeling and balanced cross-section method. Main stages of deformation have been identified. These stages were compared with geological history of Andian orogeny.

   An integrated approach to the study of the Maastrichtian deposits of the Darya River (Northern Caucasus) section served as the basis for the reconstruction of sedimentation conditions. As a result of the conducted research, conclusions were revealed about the biotic and abiotic events of that time. The stratigraphic position of the section has been clarified, and it zonal subdivision by foraminifera has been defined. The reconstruction of paleogeographic and paleoclimatic environments has been undertaken. It was found that in region in Maastrichtian there was a warm-water basin from shallow-sea to moderately deep-water with normal salinity and irregular sedimentation rate.

   The results of a comprehensive study of the deposits of the Fanar horizon of the Lower Cretaceous of the Northwestern Caucasus are presented, which made it possible to establish the conditions of their formation and the sources of the erosion of clastic material. It was defined that the territory was a frontal area of the delta, in which sandy and sandy-clay deposits accumulated in separate distributing channels. The sandstones of the horizon have good reservoir properties with a porosity coefficient (Kp) up to 21.3 %.

   The Bazhenov horizon has been studied since the middle of the last century and is still a promising prospect for oil and gas exploration. The article presents an overview of the structure of the siliceous, radiolarite, part of the separated in the section of the formations composing the Bazhenov horizon. Three morphological types of radiolarite layers were identified: well-defined layers with erosional boundaries, lens-shaped radiolarites with defined boundaries, and slightly traceable layers and single radiolarite lenses. The formation of radiolarians of different types is associated with benthic paleoflows. The localization of these types by area allowed us to assume the areas of influence of benthic paleoflows in the Volga age, due to which the most prospective exploration areas were identified.

   Experimental modeling of oil generation processes by source rocks containing concentrated organic matter of continental origin is carried out. It is shown that oil was generated when organic matter is heated, regardless of its maceral composition. The comparability of changes in the composition and properties of organic matter during closed pyrolysis with natural changes in the composition and properties of organic matter of rocks during catagenesis is shown. A comparison of the generation potential of continental organic matter of different maceral composition is given.

   Over the past thirty years, the development of space technologies and the acquisition of digital information have shown that the use of satellite sensing materials in geology is a reliable and effective method. A special role in carrying out geological prospecting and forecasting work on the territory of the Auminzatau-Beltau ore region of the Republic of Uzbekistan by the automated method of processing satellite images of various ranges is important for identifying the optimal location of gold mineralization. Target. Identification of a zone of hydrothermal alteration and a favorable position of gold mineralization.

   Equilibrium-dynamic modeling methods have been used to evaluate the possibility of redeposition of the previously formed vein Pb-Zn ore material on the carbonate barrier during the reactivation of the hydrothermal system. The natural prototype is the Ursdon ore occurrence (Dzhimidonskoe ore field, North Ossetia, Russia) localized in Oxfordian limestones (J3), and the formation of polymetallic vein deposits in the area took place in the pre-Callovian time of the Middle Jurassic. The calculations were performed using the HCh software package, which includes the Unitherm thermodynamic database (H-O-K-Na-Ca-Mg-Al-Si-Fe-C-Cl-S-Zn-Pb-Cu system, described by 54 minerals, 78 particles of an aqueous solution). It has been established that late low-temperature hydrothermal solutions can provide pyritization, silicification and the formation of Pb-Zn mineralization in carbonate rocks. The deposition of quartz and sulfides occurs along cracks and at the dissolution front of carbonate rocks.

   The adsorption properties of sand-gel material (SGM) with respect to mercury (II) ions were studied. It has been shown that studying adsorption under static conditions is incorrect, since upon contact with the sorbent, oxalates pass into the solution, forming stable complexes with mercury that are not capable of sorption. The adsorption value of mercury on SGM reaches 0.21 mg/g, and the adsorption capacity is 0.35 mg/cm³. It has been established that the studied material effectively adsorbs mercury (II) ions, and therefore can be used for wastewater treatment with mercury contamination.

   Two series of numerical experiments were conducted simulating the initiation and evolution of the subduction of the Pacific plate beneath the Northern segment of Kamchatka subduction zone. In the first series, the self-developing submergence of the slab was modeled with the initial kinematic and physical parameters of the Kamchatka subduction zone. In the second series, a new element of the regional subduction model was introduced and tested — a zone of kinematic stabilization in the asthenospheric mantle to ensure a shallower trajectory of slab submergence. In the first series of numerical experiments (without the stabilization zone), a steeply dipping subduction not corresponding to the slab configuration according to existing geophysical data was obtained, with complete absence of magmatism during the first 14 million years of model time. In the second series (with the stabilization zone), the slab configuration according to seismotomography data was reproduced, and P-T trends (geotherms) for the surface of the slab and the base of the oceanic crust (Moho boundary) were constructed. Manifestations of volcanism in the second series were observed starting from 9 million years. The volcanism is predominantly acidic in composition, and volcanic structures are located at a distance of 200 km from the trench, which corresponds to the spatial arrangement of the East Kamchatka volcanic belt relative to the trench.

   The article presents a new data on the chemical composition, content and distribution patterns of stable oxygen and hydrogen isotopes in the natural waters of the Issyk-Kul intermountain artesian basin. The complex geological and hydrogeological conditions of the research region have led to a variety of thermomineral waters in terms of chemical composition, TDS and temperature. The results showed that the studied waters of the region have an initial meteoric origin with a clearly pronounced high-altitude effect, and the fractionation of isotopes is due to secondary superimposed processes. The geological and tectonic structure of the region under consideration contributes to the formation of mineral waters of various chemical composition: carbon dioxide waters of insignificant TDS are formed within rocks and open cracks, in the case of the presence of a significant thickness of the sedimentary cover, carbon dioxide-nitrogen or nitrogen-methane waters with a TDS of more than 2,0 g/l (sometimes significantly higher up to 35,0 g/l) are formed. Ion-salt geothermometers were used to assess the deep temperatures of the formation of thermomineral waters, which showed a wide range of temperature values (from 21,4 to 144,8 °C), which indicates different conditions for the formation of the studied waters.

   The authors’ results show studies of the interaction of process fluids with rocks of the jaran horizon (D3jar), drilled within the Lyzhsko-Kyrtaelsky uplift, Timan-Pechora petroleum basin. The composition of the reservoir rocks of the studied deposits is represented by oligomictic feldspathic-quartz sandstones with carbonate-clayey and clayey-carbonate cement. The study is devoted to assessing the influence of the killing fluid on the reseruoir properties of the reservoir rock using methods for measuring open porosity and absolute gas permeability using the «Coretest System» AP-608, the liquid saturation method according to Preobrazhensky, and filtration modeling using the installation «PUMA-650».

   The specific features of ecological and geological systems of alluvial soil arrays and their abiotic and biotic components are analyzed. The features of the interrelation of the components with each other, which determine the resource potential of these EGDS, are revealed. The data on the experience of rehabilitation of similar territories for various types of economic activity are systematized.

   The change in the properties of humic acids when exposed to high temperatures has been studied. In this work, the process of hydropyrolysis of HAs was studied and their thermal stability was assessed. Experimental data on the thermal destruction of alkaline solutions of humic acid at 150 °С, 200 °С, 250 °С and saturated water vapor pressure were obtained. It has been shown that in the process of hydropyrolysis the degree of condensation of molecules changes, the number of functional groups noticeably increases and the values of weight-average molecular masses decrease. The obtained experimental results made it possible to calculate the parameters of the thermal stability of humic acids.