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For the first time, exposures of ultramafic rocks of subvolcanic origin have been investigated at the foot of Mount Khanlauta (Kola Peninsula) located at a distance of ~2 km from the southwestern margin of the Pados-Tundra layered complex of dunite-harzburgite-orthopyroxenite composition, which hosts zones of chromitite and unconventional PGE mineralization. The ultramafic body is composed of micro- to fine-grained harzburgite and subordinate orthopyroxenite and has a cryptically zoned structure. The body is of E-W strike and has a small size with an apparent thickness of ~0.1 km; the exposed outcrops exhibit a blocky surface as a result of extensive cracking caused by degassing and rapid cooling of a parental komatiitic melt. Elements of columnar parting are recognized, which have a hexagonal shape in cross section and are consistent with the inferred subvolcanic origin. Two zones are identified. Zone I is formed by a more magnesian olivine with Mg# = 86.0-87.9 (0.15-0.21 wt. % MnO). In Zone II, olivine grains are notably less magnesian (Mg# = 81.8-84.1) and invariably have higher contents of manganese (0.19-0.30 wt. % MnO). The presence of this zoning is corroborated by the lateral distribution of accessory chromian spinel grains with maximum Mg# values (>20) in Zone I. The Khanlauta rocks also contain subordinate orthopyroxene (Mg# = 86.3-87.2), amphiboles of the tremolite-actinolite series, and anthophyllite of deuteric (autometasomatic) origin along with accessory minerals: ilmenite, hematite (~15 mol.% escolaite, Cr₂O₃, in solid solution), and mono- and diphase grains of sulfides in the form of intergrowths of Co-bearing pentlandite (Ni/Fe = 0.9-1.3; 1.00-16.74 wt. % Co; up to 1.7-6.8 wt. % Cu) and heazlewoodite (locally in intergrowth with hematite). The inferred front of crystallization moved in the western direction, causing the formation of Zone II from a more fractionated melt with a notably lower Mg# value. A sharp increase in oxygen fugacity locally caused the formation of anomalous parageneses of chromite and ilmenite, in which the observed Mg# values of ilmenite are considerably greater than those of the coexisting chromite. The geochemical whole-rock characteristics based on major, minor, and trace elements (including LILE, REE, and HFSE), as well as the compositions and trends of chromian spinels, are similar to those in differentiated (zoned) sills of the Chapesvara complex, which are closely associated with the Pados-Tundra layered complex. The obtained data indicate comagmatic relationships among the Khanlauta massif, zoned sills of the Chapesvara complex, and the Pados-Tundra layered complex. All of them crystallized from a primitive highly magnesian Fe- and Cr-enriched komatiitic magma (Al-undepleted). Thus, they belong to a single subvolcanoplutonic association being part of the Serpentinite belt-Tulppio belt (SB-TB) megastructure of presumably Paleoproterozoic age.

Mantle xenoliths of fresh sheared and granular peridotites from the Udachnaya kimberlite pipe (Yakutian kimberlite province, Siberia, Russia) are studied in terms of mineralogy, chemistry, and behavior of platinum-group elements (PGE), with a focus on difference between the two types of peridotites and on the role of PGEs in their origin. The analyzed samples of sheared and granular peridotites differ in mineral-liquid equilibrium temperatures and pressures: 1230-1350 °C, 56-67 kbar inferred for the former and 750-1300 °C, 30-67 kbar for the latter. The contents of major oxides, trace elements, and PGEs differ both between sheared and granular peridotites and within each group. Some sheared and all granular peridotites are enriched in incompatible elements, have low percentages of clinopyroxene and contain garnet rich in middle rare-earth elements (MREE). These features result from interaction of the peridotites with melts and related fluids of presumably carbonate compositions containing incompatible elements in high abundances. Sheared peridotites were more strongly enriched and gained more Ca, Al, and Ti than the granular variety. On the other hand, granular peridotites have higher light REE (LREE) and lower heavy REE (HREE) enrichment, which may record compositional difference of metasomatic agents. Metasomatism acted in two stages: first silicate agents caused LREE enrichment and HREE depletion of melts and then the fractionated melts percolated through the mantle and affected the compositions of granular peridotites and, partly, sheared peridotites. The two types of peridotites differ also in PGE patterns, with largely variable Os-Pt concentrations in granular peridotite. This difference may be due to uneven distribution of the Os-Ir and Pt-Os-Ir intermetallic compounds, which formed as sulfide melting residue in the lithospheric mantle. Sheared peridotites show almost uniform Os-Pt distribution and are enriched in Pd, Re, and partly Pt. The enrichment possibly occurred during metasomatism when the percentages of garnet and clinopyroxene increased while sulfide phases precipitated into interstitials.

Based on the analysis of the petrographic and lithogeochemical features of the Middle Jurassic-Lower Cretaceous strata in the lower reaches of the Anabar River, we have studied the regularities of changes in the composition of the upper parts of the Yuryung-Tumus and Sodiemykha Formations and the lower part of the Buolkalakh Formation. It has been established that the silt-sandy rocks of the first and basal beds of the second formation are graywacke arkoses and essentially feldspathic varieties, and most of the Sodiemykha Formation is composed of quartz-feldspathic and scarcer feldspar-quartz graywackes. A chemical classification of the rocks was made; most of them were assigned to normosiallites. The rocks of the marker beds, namely, the Fe-containing deposits of the Sodiemykha Formation, the basal glauconite bed of the Buolkalakh Formation, and the overlying clay bed, were classified as hypohydrolysates. All the studied deposits are of low sedimentary maturity, with essentially petrogenic clastic material. These are predominantly igneous rocks of intermediate and, less, felsic composition. The provenances were characterized by moderate chemical weathering. In the periods of the formation of the marker beds, chemical weathering intensified, and the amount of mafic and, partly, ultramafic rocks increased. The established changes in the composition of the parental strata are observed in the Middle Jurassic-Lower Cretaceous deposits of the entire considered petromineralogical province, which permits them to be used for correlation.

The paper presents the results of the development and use of numerical methods for interpreting logging data in the Bazhenov Formation interval (Upper Jurassic). We consider wells located in the central and southeastern regions of West Siberia. Based on the machine learning method (artificial neural networks) and with the results of detailed lithological and geochemical core studies taken into account, a computational algorithm has been developed and tested to evaluate the material composition of the Bazhenov Formation rocks. In the studies we use the classification of the Bazhenov Formation lithotypes, which is based on the modern concept of the distribution of rock-forming mineral and mineraloid components. In the examined well sections, the lithologic composition of the Bazhenov Formation rocks has been determined, along with its lateral change in the central part of the Salym field, in the Surgut arch region, and in the southeast of West Siberia.

The design characteristics of the turbulent lidar affecting its thermo-mechanical stability are determined. A comparative description of two different designs is given, where different approaches are implemented to the selection of transceiving optics and receiver detectors and organization of the temperature control system for stabilizing the lidar optical bench. A simulation scheme of a lidar transceiver is suggested, including the calculation of the displacements of optical elements relative to the base points on the optical bench and the ray tracing from the laser into the atmosphere and back. The influence of the temperature gradient between the opposite sides of the optical bench on the operation of the receiving channels is considered. The results of the experimental study of lidars for resistance to temperature changes are presented. Recommendations for improving the design of a turbulent lidar are formulated.

The conditions for generation of red streamers at an atmospheric air pressure of 0.1-10 Torr are experimentally studied. The mode of generation of streamers tens of centimeters in length from the plasma of an electrodeless capacitive discharge is implemented under low pressures. A discharge between metal small-curvature electrodes transforms into a stationary mode, where streamers are not generated, as the pressure and voltage increase. It was confirmed using the ICCD camera that the streamers start from the positive-polarity electrode. The color of the discharge plasma depends on the air pressure in pulsed and continuous discharges and is most consistent with the color of red sprites at a pressure of ~ 1 Torr.

We studied the seed set of a perennial herbaceous short-rhizome polycarpic plant Galeobdolon luteum (yellow archangel) in open pollination and various options of mechanic pollination (bag directly, parthenogenesis test, cross pollination). Our surveys were carried out in 2020-2022 according to generally accepted methods in natural conditions of the Moscow region. It has been shown that G. luteum produces from 48 to 128 ovules and from 10 to 108 completed seeds per one shoot. In natural pollination, we found only two variants of coenobia (schizocarpic fruit): completed seeds are not formed in the fruit at all, or the fruit includes 4 fully formed nutlets. Our studies did not reveal the ability for apomictic seed setting in this species. In flowers of G. luteum, autogamous pollination is possible with rather sharp and significant fluctuations of flowers under the influence of various environmental factors (gusts of wind, raindrops, etc.). It was revealed that within the inflorescence of G. luteum, with simultaneous flowering of several flowers, geitonogamy is possible due to the presence of a self-compatibility system and visiting flowers by pollinating insects. In abundant cross pollination, the seed set of G. luteum is higher than in open pollination, which is due to the ingress of a larger number of pollen grains on the stigmas of flowers than with insufficient pollination carried out by insects.

On the basis of 25 years of observations (1990-2014), the types of ecological-cenotic strategies have been determined for laxicaespitose grasses Arrhenatherum elatius and Dactylis glomerata on spoil banks in the Kuznetzk Basin. In 1989-1990, seven agrophytocenoses were created on levelled open-cut spoil banks of “Listvyanskiy” coal mine. Seeding of D. glomerata and A. elatius was carried out on Quaternary and Perm deposits as a part of mixtures of grasses or grasses with legumes. Determining ecological-cenotic strategies was based mainly on revealing the following aspects: above-ground phytomass, projective cover, lifespan, hummock size, numger of generative shoots, ontogenetic spectrum. D. glomerata acts as a violent species in the grass mixtures on deposits of different geological age for the initial 14 years. But D. glomerata is an ecotopic patient species in the grass mixture with Onobrychis arenaria, in sowing with Trifolium pratense, and in the thickened clover-grass mixture (with a higher seeding rate). A. elatius acts as violent species in the grass mixtures on deposits of different geological age for the initial 4-5 years after seeding. During the subsequent years in the grass mixtures, as well as for all years in the mixture with Onobrychis arenaria, A. elatius acts as a phytocenotic patient species. The following features were also noticed. Both species, D. glomerata and A. elatius, persisted in all communities for all years of observatioin. The generative shoots of D. glomerata were emerging rather late, for the 3-4 years of life, which guaranteed fruiting of the shoots. For both species, the ontogenetic spectra laked the senile individuals (and for and A. elatius even the subsenile ones). In particular years, A. elatius was producing large quantities of generative shoots, about 100 per m²; and the numbers of individuals per m² were reaching 800 on account of seedlings.

Data on the species diversity of representatives of the genus Pseudokephyrion Pascher in water bodies of Western Siberia, their distribution by zones and subzones are summarized. To date, 17 species and intraspecific taxa are known for the region, represented by 16 species of the genus Pseudokephyrion from the Dinobryaceae family. Representatives of this family are found in mosaics throughout Western Siberia. A greater number of species (12) were found in the middle taiga; 11 taxa were identified in the forest-steppe zone; in other zones, the number varied from 1 to 5. No species were found in the steppe and forest-tundra. In lakes and streams of various types, 14 species of this genus were identified. To date, 11 species of this genus are known in the watercourses and reservoirs of the Siberian Uvaly Natural Park.

The results of a taxonomic analysis of the lichen flora of the North-Eastern Okhotsk region (Magadan Region), which currently includes 412 species belonging to 1 division, 1 subdivision, 4 classes, 5 subclasses, 15 orders, 45 families and 133 genera, are presented. The majority of the species belongs to the class Lecanoromycetes (404 species or 98 %), which is represented by 4 subclasses - Acarosporomycetidae, Lecanoromycetidae, Ostropomycetidae and Umbilicariomycetidae. The basis of the lichen flora is represented by the Lecanorales order, which unites 10 families, 53 genera and 190 species (46 % of the total species diversity). The average number of species in the family is 9.2 in the studied lichen flora. The level of species richness exceeding this indicator belongs to 12 families, numbering a total of 313 species or 76 % of the flora. The average number of species in a genus is 3. In the studied lichen flora, 24 genera have an indicator higher than this value; they include 235 species or 57 % of the total flora. The largest genus Cladonia in the lichen flora of North-Eastern Priokhotye includes 44 species. The spectrum of the leading families of lichen flora is typical of the lichen flora of the Boreal zone of the Holarctic. Boreal features are indicated by the leading position of such families as Parmeliaceae, Cladoniaceae, Physciaceae, Lecanoraceae, Peltigeraceae, genera Cladonia, Peltigera. The high position in the spectrum of the families Rhizocarpaceae, Umbilicariaceae, Stereocaulaceae, Lecideaceae, including epilithic species, indicates the mountain character of the lichen flora. Thus, the studied lichen flora should be characterized as mountain-boreal.