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The quasi-equilibrium directional crystallization method to model a new type of zoning in the Cu-Fe-Ni-S system was applied. A melt is crystallized with the following composition (in at.%): 14.00 Cu, 30.00 Fe, 4.00 Ni, 51.00 S, and 0.1 each of Pt, Pd, Ag, Au, As, Te, Bi, Pb, Se, and Sn. We use optical and electron microscopy, micro-X-ray spectral analysis, differential thermal analysis, and powder diffraction to study the composition and structure of the ingot. Based on the results of measuring the average solid phase composition, the distribution curves of macrocomponents in the ingot have been constructed in the range of g from 0 to 0.81 ( g is the fraction of crystallized melt). The variations in the melt composition and distribution coefficients between solid phases and the melt in directional crystallization have also been calculated. The obtained sample consists of three primary zones: monosulfide solid solution with the composition ranging from (Fe_0.75Ni_0.10Cu_0.06)_0.91S to (Fe_0.69Ni_0.15Cu_0.09)_0.93S (Mss) in Zone I and two intermediate solid solutions: ~ (Fe_0.57Ni_0.03Cu_0.45)_1.05S (Iss₁) in Zone II and (Fe_0.46Ni_0.06Cu_0.52)_1.05S (Iss₂) in Zone III. The peritectic character of the crystallization of Iss₁ and Iss₂ from the melt has been established. The trajectories of the melt and solid phase compositions and series of conodes have been plotted for Mss and Iss₁ on the phase diagram of the Cu-Fe-Ni-S system. Secondary zonality is described by the following sequence of phases: Pyh 1C + Pyh 3C + Icb + Ccp/Ccp + Iss + Fe-Pn, Sgk/Ccp + Ni-Pn + NiS + Bn (Pyh - hexagonal pyrrhotite, Icb - isocubanite, Ccp - chalcopyrite, Pn - pentlandite, Sgk - sugakiite, Bn - bornite) and belongs to the high-sulfur pyrrhotite + cubanite-chalcopyrite type of ore body zonation.

The Anakit intrusion had a multistage effect on the host sediments, manifested as spurrite-merwinite metamorphism, early retrograde processes and associated formation of a uniquely diverse Cl-silicate mineralization (with a Cl content of up to 7-15 wt.%), skarn formation, and low-temperature hydrothermal processes. At the eastern contact of the Anakit massif, high-temperature spurrite-merwinite marbles were studied and characterized. The major and trace element and mineral composition of the rocks and the compositions of all rock-forming, accessory, and retrograde minerals has been determined. Under peak metamorphic conditions, the temperature in the near-contact zone (0.3-5 m) exceeded 900 °C, and X _CO2 reached 0.3. The δ¹³C-δ¹⁸O trend determined for the first time is similar to those at contacts with a minimum metasomatic influence. The small difference between the δ¹³C and δ¹⁸O values of the Anakit marbles and their protoliths (Δδ¹³C ≤ 2.0‰ and Δδ¹⁸O ≤ 4.0‰) proves the predominant contribution of metamorphic decarbonation to carbon and oxygen isotope fractionation. Along with mineral indicators, it testifies to the limited infiltration of magmatogenic fluids into the host strata.

The paper presents studies of gneisses and granitoids from three deep boreholes located in the central part of the Nepa-Botuobiya anteclise of the Siberian craton. Based on U-Pb (LA-ICP-MS) geochronological studies of zircon, the age of the granitoid protolith of amphibole-biotite gneiss from Danilovskaya BH-95 has been estimated at 2254 ± 4 Ma, the age of granitoid from Mogdinskaya BH-11, at 1972 ± 9 Ma, and the age of granitoid from Preobrazhenskaya BH-14, at 1981 ± 3 Ma. The protolith of the gneiss from Danilovskaya BH-95 corresponds in composition to granodiorite similar to I -type granite with high contents of high-field strength elements (HFSE). It is characterized by T _Nd(DM) = 2.7 Ga and might have formed as a result of the melting of an Archean crustal source within a certain block. The granitoid from Mogdinskaya BH-11 has features of I -type granites with low contents of HFSE and is characterized by T _Nd(DM) = 2.4 Ga. The granitoid from Preobrazhenskaya BH-14, with T _Nd(DM) = 2.6 Ga, is similar to I -type granites with high contents of HFSE. All the available data and the similar ages (ca. 2.0 Ga) determined earlier for S -type gneiss-granites from one of the Danilovka group boreholes suggest the formation of granitoids with different geochemical characteristics in the central part of the Nepa-Botuobiya anteclise in the period 1.97-2.00 Ga. This was possible in the accretionary orogen including (as evidenced from the isotope characteristics) blocks with Paleoproterozoic and Archean crust. The studied area is a fragment of the Paleoproterozoic Trans-Siberian orogenic belt separating the large Archean Tunguska and Anabar superterranes. The formation of this belt marks the early stage of accretion processes and the beginning of the formation of the Siberian craton in the period 1.95-2.00 Ga.

The Angara-Kan terrane is located in the southwest of the Siberian Platform and is composed mostly of rocks of the Kan granulite complex and the Yenisey metavolcanosedimentary complex. In this work, we present new data on the metamorphic conditions as well as the composition and age of zircon and monazite of garnet-biotite schists of the Yenisey Complex. The textures, geochemical composition, and wide range of zircon ages indicate that the garnet-biotite schists formed during single-stage metamorphism of terrigenous rocks at P = 7.2-8.2 kbar and T = 700-730 °C. These P - T parameters are similar to those of metavolanic rocks of the Yenisey Complex. The age of the metamorphic generation of zircons and monazites from garnet-biotite schists, 720-730 Ma, is correlated with the time of Neoproterozoic metamorphism of volcanic rocks of the Yenisey Complex. The age spectra of Paleoproterozoic detrital zircons from the garnet-biotite schists show two maxima corresponding to ca. 1.86 and ca. 1.78 Ga. Granulites of the Kan Complex, which underwent two stages of high-grade metamorphism, at 1.89-1.85 and 1.80-1.77 Ga, were probably the source of these zircons. Terrigenous sediments presumably accumulated close in time to the formation of volcanic rocks of the Yenisey Complex, at ca. 1.74 Ga. We assume that most of sedimentary rocks of the Yenisey Group formed after the main orogenic events in the Angara-Kan terrane.

The article analyzes the published data and collections of brachiopods available to the authors for the systematic composition of brachiopods of the Rhynchonelliformea from the Cambrian of the Siberian platform. Currently, 50 species have been described and one taxon has been assigned to the genus (Finkelnburgia sp.). All of them belong to 15 genera, 10 families (two genera have not been identified as belonging to families), and five classes. Cambrian brachiopods of the Rhynchonelliformea of the Siberian Platform are divided into six associations, which are characterized by a certain taxonomic composition, paleogeographic and stratigraphic distribution. The most representative are brachiopods of the Obolellata. Their findings were noted in North America and Greenland and allow us to compare the deposits of the Lower Cambrian of North America and the Siberian platform quite confidently. The Strophomenata is also widely used. But of the ten Siberian species of the Billingsella genus, eight are endemic. Therefore, the findings of these brachiopods can be effectively used for correlation at the generic level to compare the transitional layers between the Middle and Upper Cambrian. Representatives of other classes (Chileata, Kutorginata, and Rhynchonellata) have less potential for inter-regional correlations. Although some of their representatives are found in other regions of the world and can be used as an additional tool for comparing remote sections.

The Severo-Ketskaya parametric well was drilled by JSC NPC Nedra to a depth of 5,200 m in the period 2021-2023. The well is located in the south-west of the Pre-Yenisei sedimentary basin in the dome zone of the large anticlinal structure of the same name, buried under the Meso-Cenozoic cover. The well uncovered a new carbonate-terrigenous section of the Vendian and carbonate deposits, presumably of Ripheanage, for the Pre-Yenisei sedimentary basin. The article substantiates the stratigraphic boundaries of the Vendian on the basis of geophysical correlations with typical sections of the southwest Siberian Platform, presents the general lithological characteristics of the Vendian section and the exposed part of the Riphean (?). According to the data of the primary core study, the results of geophysical studies and tests of objects, the deposits of the Upper and Middle Danilovskoye subhorizonts are the most promising for oil and gas accumulation in the Vendian complex of rocks in the borehole drilling area. The results of geochemicalstudies of sections of parametricwells do notallow us to associatehigh oil and gas potentialwith the Proterozoic deposits of the Pre-Yenisei sedimentarybasin

The first reconstruction of lacustrine sedimentation conditions for the extensive territory of the Angara steppe (Pre-Baikal Depression) in the Late Holocene with decadal temporal resolution is presented. The reconstruction is based on the results of a comprehensive study of Lake Ordynskoe sediments: petromagnetic and granulometric parameters, biogenic silica content. Sedimentation rates and the age of the reconstructed events were determined using radioisotope dating (²¹⁰Pb and ¹³⁷Cs). The age of the core base is 2800 cal yr BP. As a result, it is shown that the primary contribution to the magnetization of Lake Ordynskoe sediments, unlike other studied lakes in the region, comes from grains produced by magnetotactic bacteria. Nevertheless, the analysis of the behavior of biogenic magnetization components provided information on the Lake bioproductivity and relative changes in redox conditions during sediment formation at the water-bottom interface, while the results of granulometry were informative for reconstructing relative changes in lake level. Despite this specific feature of the formation of the lake sediment's petromagnetic characteristics, it was established that noticeable anthropogenic influence on the Lake Ordynskoe geosystem began approximately 280 years ago, intensifying significantly in the last century due to the agricultural activity.

Carbon dioxide is a perceptible component of Earth's atmosphere and a significant part of the atmospheres of other planets of the terrestrial group. In this work, absorption by carbon dioxide is considered on the basis of the asymptotic line wing theory. Line contour parameters have been found by fitting to experimental values at 200-300 K temperatures in the 4.3 mm CO₂ band. The different temperature behavior of the absorption is noted near the band (2400-2440 cm^-1) and far from it (2500-2590 cm^-1). The results of this study are of interest for spectroscopy and can be important in atmospheric modeling.

Consideration of absorbing and scattering properties of atmospheric aerosols and estimating the sizes of aerosol particles are important for testing standard and creating regional algorithms of atmospheric correction of satellite data. However, calculation of optical characteristics of atmospheric aerosols in dust transport periods is complicated by a need in considering the effects of dust aerosol on optical properties of the atmosphere: aerosol optical depth (AOD), Ångström parameter, and others. In this work, the optical characteristics of atmospheric aerosol are analyzed based on in-situ photometric measurements, MODIS (Aqua/Terra) and VIIRS satellite data, and HYSPLIT simulation for two Volga reservoirs and the Black Sea during dust transport from the Sahara and Karakum deserts. The AOT values are found to be more than two times higher than background values during all the events under study. No differences in the optical characteristics of dust aerosol transported from these deserts were detected. The results can be used to verify standard algorithms of atmospheric correction of satellite data.

The results of complex studies of filamentation of high-power femtosecond laser pulses in experiments where a localized air layer with a randomly inhomogeneous refractive index (artificial turbulent layer) is created at the beginning of the propagation path are discussed. It is shown that the technique of forced chaotic modulation (power stochastization) of a radiation beam, which initiates inhomogeneities in the transverse energy structure of laser radiation, causes the splitting of an original beam into many high-intensity light subbeams (channels) due to strong optical nonlinearity of the air medium. These channels are characterized by high intensity and stability along significant distances. The segmentation of the radiation by a turbulent layer multiply increases the number of high-intensity optical channels, which arise during propagation of a 2.5-cm beam of a Ti:Sapphire laser with a wavelength of 800 nm and power of up to 150 GW in air. The characteristic intensity of these optical channels is high enough for two-photon absorption in a volume of colored (rhodamine or uranine with a concentration of 0.4 g/l) water aerosol microparticles, created at the end of a 100-m optical path, which, in turn, almost doubles the fluorescence signal from the particles recorded by the lidar scheme. In addition, it was determined that a localized turbulent layer created at the beginning of an optical path enables a multiple enhancement of the efficiency of low-frequency (THz) electromagnetic radiation generation from laser filamentation region.