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Identifying patterns of geographic differentiation of individual groups of marine invertebrate fauna in the geological past is important for understanding their evolutionary history, solving issues and problems of biostratigraphic division, and correlation of deposits. Paleobiogeographic data is also necessary to identify the development stages of biota and the geological history of marine paleobasins and verify paleogeodynamic reconstructions. In this work, considering the latest data on paleontology and biostratigraphy of the Boreal Triassic, the taxonomic composition and distribution of Upper Anisian ammonoids in various regions of the Boreal realm are revised. A correlation of Upper Anisian deposits of Northeast Asia, British Columbia, Canadian Arctic Archipelago, Svalbard, Franz Josef Land, and Khabarovsk Krai was carried out at the zonal level and a basis was obtained for a comparative analysis of coeval ammonoid faunas. As a result of a qualitative and quantitative comparative analysis of ammonoid assemblages for various phases of the Late Anisian age, it was established that in the Late Anisian age, British Columbia was constantly part of the Canadian province of the Boreal realm, and Northeast Asia was part of the Siberian province. At the end of the Late Anisian age (most of the late part of the Frechites nevadanus or Frechites chischa phases), provincial differences were smoothed out and for the first time, all Boreal regions were included in the Siberian province, except the territory of British Columbia. Analysis of the geographical distribution of some groups of ammonoids in the Late Anisian age and changes in the areas of taxa over time made it possible to identify probable migration routes of Longobarditidae ( genus Longobardites ) and to introduce significant changes in the ideas about the centers of origin and migration of some Beyrichitidae.

This paper presents a solution to the problem of searching for cavernous fractured zones and the zones that determine reservoir heterogeneity in Famennian deposits of one of the licensed sections of the Republic of Bashkortostan. The use of an integrated approach to the study of azimuthal horizontal-transverse isotropy of rocks using wellbore data and modern methods for processing areal seismic data for carbonate deposits associated with the development of organogenic structures is described. The results of using the full-azimuth angular migration technology are obtained. The introduction of high-tech approaches at the research site using full-azimuth seismic data processing, spectral decomposition, AVA/AVAZ inversion, and complex analysis of dynamic properties of the wave field in conjunction with well logging and core data makes it possible to identify the distorted zones of the carbonate reservoir associated with changes in the characteristics of the rock skeleton, the presence of a porous-cavernous-fracture void space and lithological replacement zones, as well as secondary processes, thereby reducing the risks associated with subsequent production drilling.

The degree of organic-matter (OM) maturation in Proterozoic, Paleozoic, and Mesozoic deposits in the Anabar-Khatanga saddle has been determined from examination of the reflectance of macerals (mainly vitrinite). The Proterozoic deposits contain only graphite inclusions of uncertain origin. In the Cambrian, Devonian, and Carboniferous strata, OM has transformed predominantly to apocatagenesis grades (АC_2-3). Similarly transformed OM (АC_1-3) is found in the lower Permian Tustakh and Lower Kozhevnikova formations. In some wells and areas, the degree of OM catagenesis is not higher than МC₁²-МC₂ grades (classification after A.E. Kontorovich). In the Upper Kozhevnikova Formation, catagenesis grades are within МC₁¹-АC₁ in the upper Permian and within МC₁¹-МC₃² in the Triassic. In the Jurassic deposits, OM has transformed to early mesocatagenesis grades (МC₁¹-МC₁²) and reached МC₂ at the most deeply buried segments. In the Cretaceous strata, OM is less transformed, corresponding to PC₃-МC₁¹ or, seldom, higher grades of catagenesis. Some complexes in the Permian, Triassic, and Jurassic-Cretaceous deposits with OM of moderate maturity might be petroleum-promising.

Smectite illitization geothermometry has been used to assess the thermal maturity and hydrocarbon generation potential of the late Paleocene to early Eocene Patala Formation in the Upper Indus Basin. X-ray diffraction (XRD) detected illite, muscovite, quartz, kaolinite, chlorite, and calcite. Comparison between air-dried (AD) and ethylene glycol (EG)-solvated XRD patterns reveals the absence of discrete smectite and interstratified illite-smectite (I-Sm). Additionally, authigenic illite-2M₁ indicates that the Patala Formation has entered the late-stage diagenetic zone or the low anchizone, which lies in the R3 illitization zone. Abundant SiO₂ and Al₂O₃ in the Patala clay fraction indicate the substitution of tetrahedral Si⁴⁺ by Al³⁺ within the smectite interlayers. Likewise, the relative abundance of K₂O to CaO and MgO indicates the exchange of K⁺ with Ca²⁺ and Mg²⁺ during smectite illitization. Scanning electron microscopy (SEM) reveals in situ growth of platy illite crystals that form within the R3 zone. Furthermore, the total organic carbon (TOC) of the Patala shale exposed in Tirah suggests a poor to good source rock. The absence of discrete smectite and I-Sm, combined with the detection of discrete illite in the Patala shale, suggests that hydrocarbon might have potentially migrated from the source to the reservoir rock during smectite illitization.

This paper presents results of experimental studies of a thermal field in the barrel of a shut-in (no fluid movement in the casing) well in relation to determining a behind-the-casing upward flow using the method of active thermometry. The studies are carried out using the physical model of a well that is a vertically located steel pipe with a system of externally attached copper tubes simulating a behind-the-casing flow. The pipe contains a local heating section, above which a temperature probe is located to record thermal disturbance from the heating section. The effect of free convection in a fluid on the temperature field in the pipe during and after heating is described. It is revealed that there are high-frequency temperature oscillations on sensors that record the temperature of the inner surface (wall) of the pipe and fluid above the heating area, whose value reaches higher than 2 °C and decreases when the distance to the heating region becomes longer. There is an empirical relationship that relates the time of arrival of the temperature disturbance front associated with free convection and the distance to the pipe heating region. Azimuthal temperature distribution curves on the inner wall of the pipe above the heating section are constructed in the absence and presence of a behind-the-casing flow. Qualitative criteria have been obtained indicating the presence of an azimuthally localized behind-the-casing flow (sector flow) of fluid based on the azimuthal temperature distribution analysis.

Years after the Chuya earthquake of 2003, geological structures adjacent to the focal area of the Chuya earthquake are still seismically active. The Aigulak focal area is one of them, but energetically the most pronounced. Detailed studies have been carried out with the network of stations of the Altai seismological testing site, supple-mented by temporary stations. The region activated in the form of a local and compact structure measuring 10 × 10 km with focal depths from the first 100 m to 20 km. The focal area is not a subsequent activation along the same fault with the Chuya earth-quake, but is located on a subparallel fault in the nodal region with its branching into three faults. The seismic activation of the Aigulak focal area is not an aftershock pro-cess after a major earthquake, but is an activated structure with a dynamically changing seismic process. An intensive process has formed since the earthquake in 2012 with M_L = 6.1 with a gradual decrease in the number of earthquakes, and in 2019 the Aigulak earthquake with M_L = 5.5 occurred with a very strong aftershock process after it. Our results of an area study of earthquake density in the focal zone indicate a change in the regime over time: from chaotic to self-organizing along short faults. We conclude that the focal area has not reached the maximum level of seismic energy release.

Three-dimensional transport and transformation models make it possible to take into account the vertical heterogeneity of atmospheric processes. However their use requires setting a large number of parameters and significant computing resources, especially when solving inverse and data assimilation problems. A new data assimilation algorithm for a three-dimensional transport and transformation model with unknown emission sources is presented, which uses an approach based on sensitivity operators and ensembles of solutions of adjoint equations implemented in the IMDAF inverse modeling system for distributed memory computers. When tested in a realistic Baikal region scenario, the algorithm enabled, based on the data of integrated vertical measurements simulating remote sensing data, reducing the error in the concentration field by 15%. With the given vertical level of the source location, the errors in the concentration field and in the source were reduced by 93% and 85%, respectively.

The information on the cloud liquid water path (LWP) is necessary for many applications including global and regional climate modelling, weather forecasting, and modelling of the hydrological cycle. The results of derivation of the land-sea LWP contrast from satellite measurements of LWP by the SEVIRI (Spinning Enhanced Visible Infra-Red Imager) instrument over land and water bodies in Northern Europe are presented. When studying the diurnal cycle of the LWP contrast for some water bodies, two separate maxima were discovered, which were observed nearly symmetrically relative to noon on the UTC time scale. In most cases, these maxima were present at measurement locations in the Gulf of Riga and in the Gulf of Finland in the Baltic Sea. Presumably, these maxima are an artefact of observations caused by the so-called “cloud bow effect”. Calculations of a scattering angle for the satellite measurements at these locations confirmed this conclusion. The problem of filtering out the data and the problem of analysing the data in case of possible manifestation of this confounding effect are discussed. The proposed approach to data analysis and the results can be used to assess the quality of LWP measurements by SEVIRI in various regions of the globe.

The climate of mountain regions is studied much worse than of plain territories. We suggest a model of the distribution of temperature field parameters in the lower troposphere over the Caucasus, which is to enable estimating the thermal resources of mountainous regions. Based on temperature sounding data at altitudes of 1500, 3000, and 5000 m from six aerological stations located on different sides in the mountainous country and regression and statistical analysis, we retrieve the temperature fields and distribution in the lower troposphere. The monthly average characteristics of the temperatures are presented; the effect of orography on the temperature regime is studied. The use of aeroclimatic temperature indicators makes it possible to indirectly estimate the thermal resources of mountain regions from analog station data for their effective use in economic activity.

The influence of synoptic conditions at the 700 hPa isobaric surface on meteorological regime and melt of the Sygyktinsky glacier (Kodar Range) in the 2021 ablation season was studied. Totally 15 weather types were classified using the Jenkinson and Collison method. It was found that the most frequent types are cyclones (24%) and anticyclones (20%). A significant dependence of the meteorological regime of the glacier on synoptic conditions was revealed. Anticyclonic types are characterized by high temperatures and low relative humidity and cloudiness. For cyclonic types, the opposite relations are observed. It was found that the radiation regime on the glacier and its melting rate depend on synoptic conditions. The greatest contribution to melting was made by anticyclonic weather types (44%), and the least by cyclonic types (26%). The net radiation of the glacier in anticyclones was 2-2.5 times greater than in cyclones, and the ablation rate was 1.6-1.8 times greater. The differences between the energy fluxes used for glacier melting under different synoptic patterns are explained by the cloudiness. The different atmospheric circulation regimes over the Kodar significantly affected the deglaciation of the Kodar glaciers in recent decades.