The phase transition in the structure of the PdBi₂ compound was studied using high-temperature in-situ methods (differential thermal analysis, high-temperature single-crystal X-ray diffraction). The structures of PdBi₂ polymorphic modifications were refined at temperatures of 300, 373, 473, 573 and 637 K based on the high-temperature single-crystal X-ray diffraction data. A low-temperature modification of α-PdBi₂ is monoclinic, space group C₂/m (a = 12.726(1)A, b = 4.2605(4)A, c = 5.5668(5)A, β = 102.51(1) °, V = 299.95(5)A³, Z = 2). It is stable in the temperature range from 300K (27 °C) to 573K (300 °С) and is corresponding to the mineral froodite. A high-temperature modification of β-PdBi₂ was fixed at the temperature 673K (400 °C). The phase β-PdBi2 is structural analogue of the mineral urvancevite: it’s tetragonal, space group I4/mmm (a = 3.3876(3) A, c = 13.092(2) A, V = 150.24(4) A³, Z = 1). The phase transition refers to a type I and is a reconstructive polymorphic transformation with a rearrangement of the first coordination sphere.

Geochemical peculiarities of Pleistocene sediments from the Pacific and Atlantic oceans have been compared. We used almost 20000 determinations of elements for the Atlantic Ocean sediments and more than 47000 determinations for the Pacific Ocean sediments to calculate their mean chemical composition. Pacific hemipelagic clays and volcanic sediments are rather close by their composition. It differs them from the Atlantic Ocean. It was revealed that in average Atlantic sediments are more calcareous than Pleistocene sediments of the Pacific Ocean (32.09 mas. % СаСО₃ vs 18.18 mas. % СаСО₃, respectively). They are enriched by MgO and P₂O₅ and have a higher LOI. The Pleistocene of the Pacific Ocean is enriched by oxides of other major elements (SiO₂, TiO₂, Al₂O₃, Fe₂O₃, MnO, Na₂O, K₂O). Mass accumulation rates of all chemical components for main lithological types (with exclusion of hemipelagic clays) dominate in the Atlantic. We proposed that these results are due to higher ratio of watershed area to accumulation basin area in the Atlantic Ocean.

The extremely high productivity of the Norilsk ore-bearing intrusivs exceeding the palladium (20,000 times as much) and platinum (3,000 times as much) productivity of the largest Pt–Pd giant Bushveld, is shown. Such a huge difference cannot be explained by any differentiation processes. The largest igneous formation in the world, which is the Siberian Trap and the associated largest in the world Norilsk palladium deposits conform to the boundary of the terminal Permian and the Early Triassic corresponding to the most powerful impact event on Earth in East Antarctica. A hypothesis for the possible impact initiation of the superplume that generated the Siberian trap formation and the largest Norilsk Pd deposits has been suggested. This correlates with data on the palladium and platinum geochemistry in the terrestrial planets.

The article presents new factual materials of the Sarychek deposit. The distribution of petrogenic, ore and rare elements in the rocks of the quarry base is also examined. It seems that the rare metal specialization is due to the manifestation of quartz-containing syenite porphyry rods.

Pore water composition study is an effective diagnostic tool to understand and interpretate the physical and chemical processes during water-rock interaction. The correct choice of the laboratory extraction method directly defines the quality of its chemical composition results interpretation. The paper reviews the leading modern pore water extraction methods — the centrifugation, Rhizon samplers, high-pressure squeezing, indirect method of water extraction and the method by viscous fluid displacement. The paper presents a number of advantages and disadvantages of these methods, and also characterizes their effectiveness for low permeability rocks with different water saturation.

The paper examines the main factors of the formation of the Buruktal deposit, including paleogeographic, paleoclimatic, morphological, petrological and endogenous. A step-by-step scheme for the development of the weathering crust has been drawn up, providing for the polygenic genesis of the deposit. As a result of a comparative analysis, the main features, similarities and differences in the conditions for the formation of nickel-bearing weathering crusts in the Southern Urals and New Caledonia were identified.

The article considers the deposits of the Late Riphean age, which can potentially be considered as oil and gas source deposits on the East European platform and adjacent folded areas. The data on the interlayers of rocks of the Upper Riphean enriched with organic matter are generalized and systematized. The available data on the characteristics of the organic matter of these rocks are systematized. A comparison of the Upper Riphean sections of this territory is given.

Current estimates of the potential of the oil and gas source strata of the Pre-Ural foredeep are based on geological models of its structure and oil and gas potential created based on the results of regional and exploration work carried out mainly at the end of the last century, and need to be revised and updated based on new geochemical data and modern technologies. The contribution of the Lower Permian source rock formation and their generation potential have also not been clarified. The purpose of this article is to assess the Lower Permian source rock formation from the point of view of lithology, geochemistry, and to evaluate the possibility of their generation in the Pre-Ural foredeep using the example of the Divinskaya Formation.

The paper presents a forecast of calcium, barium and strontium sulfate salt deposition for the Nepa-Botuoba oil and gas condensate field. The salt deposition forecast was made using both analytical calculations by the Oddo and Thomson method and thermodynamic modeling. As a result of determining the amount of sulfate salts that could precipitate, it was established how much the permeability of the bottomhole formation zone and the oil production rate of producing wells could potentially decrease due to the precipitation of gypsum, barite and celestine.

The results of two experiments on the interaction of fluorine-containing granite melt and calcite with the same initial composition of the dry batch and different regimes of volatile components are presented. It is established that in both cases, at the boundary of calcite and fluorine-containing granite melt at given p-T parameters, an intensive transfer of matter occurs. In addition to other components, W and Mo are transferred from the silicate melt to the carbonate part, where they are deposited as molybdenum-containing scheelite.

Comparison of the obtained samples allows us to qualitatively assess the effect of the fluid composition in the studied system on the stability of the resulting phases and the possibility of transporting ore components.

This paper explores the relevance of applications of Data Science methods in petroleum geochemistry. In order to investigate this topic, a methodology for searching, gathering and analyzing scientific papers published in the last decade was developed and successfully applied. The study reveals a growing interest in integrating Data Science methodology into petroleum geochemistry. The article also presents specific examples of found publication, identifies key “problems” hindering widespread Data Science adoption in geochemistry (including the need for result verification, shortage of qualified specialists, issues regarding access to data and negative sentiment towards new methods), and proposes promising ideas for further utilization of data science methods to tackle challenges presented by organic geochemistry (geological assistants, open access geological and geochemical databases and specialized digital toolkits and software.

The aim of the work is to select a method for studying the quantitative characteristics of the reservoir properties of the pre-Jurassic oil and gas complex of Western Siberia according to 3D seismic data and testing it on real data.

The weathering crust in the Pre-Jurassic complex of Western Siberia was chosen as a methodological example, since with its relatively small capacity (from 0 to 50 meters) reflections from the roof and the sole are not separated. The amplitude-frequency response of this interference reflection depends on the thickness, and therefore some seismic attributes may react to this.

To clarify these connections, full-wave seismic modeling using the spectral element method was used for the first time within the framework of the advanced domestic CAE FIDESYS software developed by graduates and staff of the Chair of Computational Mechanics of Lomonosov Moscow State University and adapted by staff and graduate students of the Geological Faculty of Moscow State University to solve the tasks set. This article presents the first results of their practical use. According to comparative calculations, it has been established that the traditional beam modeling methods previously used in seismics, coupled with convolution with reflection coefficients, give false results and therefore are not recommended for further use.

The proposed and tested technology made it possible to build a forecast map of the thickness of the potentially oil and gas-bearing weathering crust in the roof of the of the Pre-Jurassic complex on the 3D survey area.