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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.

New insights in the aeromagnetic data over the Central Iranian Microcontinent (CIM) have revealed interesting results for future studies and exploration. This work presents the interpretation of different magnetic analyses and the calculated 3D inversion model to provide important insights into the distribution of igneous rocks in the area that may be traced under significant cover. By analyzing several hundred magnetic susceptibility data points and aeromagnetic anomalies of known igneous rocks over the area, it was determined that mafic-ultramafic intrusive rocks generally have a high magnetic susceptibility and produce a strong magnetic response. Intermediate-felsic intrusive rocks have a low magnetic susceptibility and show a smooth gradient variation and commonly regular shape. Volcanic rocks show a wide range of magnetic susceptibility; therefore, the aeromagnetic anomalies are often random or show strong amplitude with high frequency signals and are rapidly eliminated when an upward continuation is applied. Based on the results of analysis of different magnetic maps and 3D inversion of data, and combining this information with known outcropped of igneous rocks, we revealed 1215 concealed intrusive rocks and 528 volcanic rocks in the area. We also renewed the boundaries of tens outcropped igneous rocks. The known and new mapped igneous rocks can be identified as 12 regions (or zones) for intrusive rocks and 4 regions for volcanic rocks. The results indicate that the mafic-ultramafic rocks are mainly located in the Sistan suture zone of eastern Iran along the Nehbandan fault zone. They also show that the many parts of the Lut block as the main structure of CIM have been under magmatic events, so that most of concealed igneous rocks are distributed in the middle and southern part of the Lut block. Volcanic rocks are widespread in the southeastern and northern parts of the area such as the Urumieh-Dokhtar Magmatic Arc, North Lut, and Bam region.

The latest results on electromagnetic geothermometry and its use in geothermics and geothermal exploration have been covered. Temperature models for the well-known geothermal areas, Larderello-Travale (Italy), Soultz-sous-Forêts (France) and Hengill (Iceland), constructed from electromagnetic sounding data and temperature well logs have been analyzed. 2D temperature model built along the magnetotelluric profile crossing the Travale (Italy) geothermal system allowed to locate a potential supercritical reservoir at the depth between two isotherms, T_SCF ~ 400 °C and T_BDT ~ 600 °C, coinciding with the seismic reflectors, detected earlier. 3D temperature model of the Hengill (Iceland) geothermal area built up to the depth 20 km, using electromagnetic sounding data, allowed us to locate high-temperature magma pockets at shallow depth (2-5 km); these magma pockets can be regarded as targets for geothermal exploration. Joint analysis of the specific resistivity and temperature models, taking into account gravity anomalies, allowed us to locate the zones of different thermal regimes within the crust; this, in turn, explained the observed seismicity pattern by thermo-mechanical properties, rather than by crust spreading. Deep temperature model, built for the Soultz-sous-Forêts (France) geothermal area from magnetotelluric data and temperature well logs, used to locate deep heat sources and predict heat transfer mechanism at depth up to 8 km.

This paper presents the results of experimental panoramic measurements of the temperature field by a method based on the registration of laser-induced fluorescence of the hydroxyl radical (OH) upon excitation of two different transitions (two-line PLIF) in a laminar conical flame of a gas-droplet mixture of ethyl alcohol and air. Laminar flow of the uniformly mixed ethyl alcohol/air mixture with fine droplets is produced by an ultrasonic atomizer inside the liquid ethanol tank. The properties of the two-phase flow at the nozzle outlet without combustion was controlled by a time-of-flight optical sensor. The temperature field was estimated based on the excitation of the Q₁(5) and Q₁(14) lines of the (1-0) transition of the A²∑⁺ - X²π electronic system. The spatial unevenness of the energy distribution in the laser knife illuminating the central plane of the flame cone and the change in the pulse energy from frame to frame were compensated by the use of an additional camera recording the laser radiation intensity distribution in the calibration cuvette.

Structurally stressed hydrocarbons (SSHs) have improved energy performance compared to conventional liquid hydrocarbons. The ignition induction period of mixtures of SSH vapors with air has been studied as a function of temperature and excess air ratio. The results are compared with similar results for mixtures of vapor of n -alkanes with air. The ignition induction periods of mixtures of vapors of two SSH with air are determined. Data on the ignition delay of air-fuel mixtures are required to design engine combustors and to develop and evaluate the possibilities of using new fuels.

The authors discuss the influence exerted by the structural features of placers and by the distribution of useful components in them on the efficiency of the resource-saving mining. Considering clustering occurrence of gold ore seams, a geometrization error may reach 100% in some areas of operation. The errors of reserve appraisal are defined, and the applicable approaches to mineral exploration, mining and processing control are discussed. In terms of some placers in Yakutia, it is shown that the main causes of errors in gold reserve appraisal include inaccurate determination of the placer morphology and structure, the width first of all, as well as the gold content.

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.