ISSN PRINT:1816-5524 ISSN ONLINE:1816-5532 The journal Vestnik Kamchatskoy regional'noy assotsiatsii «Uchebno-nauchnyy tsentr». Seriya: Nauki o Zemle (Vestnik KRAUNTs. Nauki o Zemle) translated as "Bulletin of Kamchatka Regional Association «Educational-Scientific Center». Earth Sciences" publishes the results of the original fundamental and applied investigations in Earth Sciences (geology, geophysics, geochemistry, hydrology, volcanology, seismology), that were not published or send for editing and further publication in other Russian and foreign journals. The journal contains not only research articles but also information on: the modern state of geosciences development in the region, the main scientific events in the region (conferences, meetings, seminars, expeditions, field schools).
Институт вулканологии и сейсмологии ДВО РАН
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Gabbro and dolerite in morfostructure of the Southern Kambalny Dalniy thermal field (Kamchatka)
For the first time in scientific studies of geothermal manifestations in the Kambal Volcanic Range, within the South-Kambal Far Thermal Field, subvolcanic-facies intrusive rocks (gabbro and dolerite) have been identified, forming steeply dipping, columnar bodies with tectonic boundaries. The composition and nature of secondary alterations in the gabbro and dolerite are examined. It is hypothesized that these rocks may serve as a source of ore material in modern hydrothermal-metasomatic processes. A schematic geological map of the South-Kambalny Dalny Thermal Field has been compiled. The host rocks of the thermal field are andesite basalts: flows of massive and agglomeratic lava dip gently (on average, 18–20°) to the northwest, indicating that the center of volcanic eruptions was located in the southeast, beyond the boundaries of the modern steam-hydrothermal discharge zone. It is shown that hydrothermally altered rocks are widespread within the boundary of the temperature anomaly and are of recent origin due to the discharge of geothermal steam and thermal waters along the main linear fault and the system of tectonic fractures flanking it.
Copyright (c) 2026 И.А. Бойкова, С.Н. Рычагов https://creativecommons.org/licenses/by-nc/4.0
The 75th Anniversary of Vladimir A. Poletaev
К 75-летию со дня рождения Владимира Алексеевича Полетаева, заведующего лабораторией гидросейсмологии Камчатского филиала Единой геофизической службы РАН, кандидата геолого-минералогических наук, ветерана геологической службы Камчатки.
Copyright (c) 2026 Редакционная коллегия https://creativecommons.org/licenses/by-nc/4.0
The 70th Anniversary of Andrey I. Kozhurin
К 70-летию Андрея Ивановича Кожурина — доктора геолого-минералогических наук, заведующего лабораторией активной тектоники и палеосеймологии Института вулканологии и сейсмологии ДВО РАН.
Critical remarks on the publication by А.D. Konoplin and V.A. Shchapov «Comments on the article by D.S. Tyagunov and A.F. Shestakov “Registration of low-frequency electromagnetic emission by a magnetomodulation sensor in laboratory experiments on the destruction of rock samples”»
This paper presents a critical review of the publication «Commentary on the Article…» and demonstrates the invalidity of the conclusions drawn therein, which were reached by analyzing the results of the article under review and comparing them with data from similar experiments published in other sources. Several serious inconsistencies and contradictions were identified, which casts doubt on the reliability of the results presented therein. In particular, a comparison was made of the most representative excerpts from the «Commentary on the article...» and its fragments, indicating that the authors of the commentary have only a superficial familiarity with the subject of electromagnetic emission (EME) signal research and the results of numerous studies conducted in this field. Some aspects of the hypothetical mechanisms for the occurrence of recorded EME signals in a magnetic field are discussed, which do not have an appropriate reasoned justification and are based on the comment authors’ distorted understanding of such a complex physical phenomenon as EME generation.
Copyright (c) 2026 А.Ф. Шестаков, Д.С. Тягунов https://creativecommons.org/licenses/by-nc/4.0
Baransky volcano (Iturup Island, Southern Kuril Islands): modern solfataric and hydrothermal activity
This paper presents the results of a study on the current state of hydrothermal activity at Baransky Volcano (Iturup Island, Southern Kuril Islands) conducted in July 2025. The geological features of the volcanic edifice that govern the origin and intensity of hydrothermal activity are examined. Thermal imaging data are provided for three major hydrothermal discharge zones of the volcano: the Verkhnee Solfataric Field, the Starozavodskoye Solfataric Field, and the valley of the Kipyashchy Stream. A comparative analysis of the recorded temperature values with published data from previous years was conducted. It is shown that over the past 11–12 years, minor changes have occurred in the regime of the most active hydrothermal vents: temperature values have increased by several degrees, and some vents have exhibited increased intensity and duration of steaming. At the Starozavodskoye Solfatar Field, two groups of vents that had previously ceased activity have also resumed discharge.
Copyright (c) 2026 Ф.А. Романюк, А.В. Дегтерев https://creativecommons.org/licenses/by-nc/4.0
Lenticular transformed basin Romanche (equatoral Atlantic): morphology, evolution, geodynamics
The morphology of lenticular transformed basins (LTB) in transform fault zones is examined, using the Romanche LTB as an example. Such systems are unique for the Global Ocean and reflect a complex combination of spreading and strike-slip processes of thin oceanic crust. The following morphostructural provinces are identified within the LTB: an accretionary massif province with a sealed passive trough valley, an active transform trough province, and northern and southern framing provinces. A morphostructural map has been compiled. The morphology of a series of marginal ridges located on the Northern Framing Ridge of the Romanche LTB is examined. These ridges formed in local transpression settings and are sensitive to changes in geodynamic regimes. It is hypothesized that they may be markers of regional geodynamic restructurings. An attempt is made to trace the formation and transformation history of the eastern marginal ridge. Two abrasion levels and a carbonate platform with a ring-reef structure indicate a complex, at least two-stage, uplift history of the Fillsbury Ridge.
Copyright (c) 2026 К.О. Добролюбова, Н.Н. Турко, А.С. Абрамова, С.А. Докашенко https://creativecommons.org/licenses/by-nc/4.0
Spatial model of the Earth’s magnetic field components «SPBF IZMIRAN» for the year 2025 epoch and its application in geological and geophysical practice
A global spatial model of the absolute values of the Earth’s magnetic field components, «SPbF IZMIRAN» for the 2025 epoch is presented. The model is based on an updated vector magnetometric database with an IGRF-14 reference frame. The digital hybrid grid model has been verified by vector measurements at geomagnetic observatories of the World Network, at the levels of aeromagnetic and hydromagnetic surveys, and at the flight altitudes of the CHAMP and Swarm satellites. Component models of the auroral zones of the northern and southern polar regions have been constructed for altitudes of 0–1000 km. The dynamics of changes in magnetic field components, the evolution of the positions of auroral ovals, and ionospheric irregularities affecting the quality of radio communication in high-latitude regions have been studied. The high-resolution «SPbF IZMIRAN» component model is used in maritime, air, and aerospace navigation and is in demand for studying the structure of the Earth’s crust and searching for mineral deposits.
Copyright (c) 2026 А.А. Петрова, О.В. Латышева https://creativecommons.org/licenses/by-nc/4.0
Comparison of the resolution capability of electrotomography arrays in the study of ground hydraulic structures
Electrical tomography is used in the diagnostics of ground hydraulic structures (HS). Measurements are carried out using various arrays. This paper examines the resolution of the most commonly used arrays: Wenner, Schlumberger, and forward and reverse three-electrode. Numerical 2-D modeling of electrical tomography soundings with these arrays was conducted on the proposed geoelectric model of an earthen dam, using RES2DMOD version 3.01 and RES2DINV version 3.4 programs for solving forward and inverse tasks. Calculations showed that the best convergence of the inversion to the specified geoelectric model of the dam is achieved by forward and reward three-electrode array sounding. Experimental work conducted on two earthen dams confirmed the advantages of using electrical resistivity tomography with a combination of three-electrode arrays for studying the condition of the hydraulic structure. This array allows for obtaining a resistivity section at greater depths, and also for localizing anomalies with lower resistivity values, indicating waterlogged soils and areas of increased water seepage from the reservoir.
Copyright (c) 2026 О.И. Федорова, В.Ю. Горшков https://creativecommons.org/licenses/by-nc/4.0
Mineralogical features of the Lower Cretaceous rocks formation of the De-Friz Peninsula (Southern Primorye, Russia)
Based on the mineral composition of the cement in the volcanogenic-sedimentary Lower Cretaceous rocks of the Lipovtsy and Galenki formations (Nikanka Series) on the De-Friz Peninsula (near Vladivostok, South Primorye, Russia) it was suggested that some of these rocks formed in shallow-water marine environments under conditions close to arid ones, and that the presence of corrensite in the Lipovtsy Formation, and the association of corrensite with laumontite in the Galenki Formation may have important stratigraphic significance for refining the Early Cretaceous age boundaries. The mineral composition of the cement in one of the sandstone samples is unusual. It consists of a layered silicate that does not swell when treated with organic solvents. This is the first time such a mineral has been discovered in volcanogenic-sedimentary rocks in the northwestern part of the transition zone from the Asian continent to the Pacific Ocean. It is proposed that it formed during the epigenesis of the Galenki Formation sediments, which were deposited along the shoreline of a desalinated basin level fluctuation and temperature conditions changing.
Copyright (c) 2026 А.В. Можеровский, Н.Н. Баринов https://creativecommons.org/licenses/by-nc/4.0
Late cretaceous-paleogene shoshonitic volcanism of the eastern margin of Asia (on the example of the Koryak Highlands, Kamchatka, the Lesser Kuril Ridge and Korea)
The composition of volcanic rocks from the Upper Cretaceous-Paleogene shoshonite complexes of the eastern margin of Asia was studied. It has been showb that the Pb, Sr, and Nd isotopic composition in the shoshonite series rockss indicates a mantle source depleted in radiogenic isotopes. The behavior of incompatible elements and their ratios allowed us to distinguish two groups of rocks. The first group includes basalts, trachybasalts and trachyandesite basalts of the Olyutor segment of the Achaivayam-Valagin paleoarc and the West Kamchatka (Palana) paleoarc, the Tumrok Ridge of Kamchatka, and the islands of the Lesser Kuril Ridge, the second includes basalts, trachybasalts and trachyandesite basalts of the Valaginsky, Kumroch and Sredinny Ridges in Kamchatka, and the Kilchu-Mencheon graben in Korea. It is assumed that the diversity of petrochemical characteristics of shoshonites in the regions under consideration is due to both to the composition of the magmatic source (the presence of phlogopite- or amphibole-containing phases) and the ratio of fluid-mobile elements (participation of fluids/melts to varying degrees in the process of magma generation), as well as changes in the subduction regime — the transition to a deeper level of magma generation and the involvement of the arc in the extension zone in connection due to rifting processes.
Copyright (c) 2026 П.И. Федоров, Н.В. Цуканов, Д.В. Коваленко https://creativecommons.org/licenses/by-nc/4.0
Памяти Сергея Александровича Хубуная, кандидата геолого-минералогических наук, заведующего Научным музеем вулканологии Института вулканологии и сейсмологии ДВО РАН.
The 70th Anniversary of Dmitry F. Kalinin
К 70-летию Дмитрия Федоровича Калинина — члена редколлегии нашего журнала, профессора кафедры геофизики Санкт-Петербургского горного университета.
The 90th Anniversary of Ivan V. Melekestsev
К 90 летию Ивана Васильевича Мелекесцева — главного научного сотрудника Института вулканологии и сейсмологии ДВО РАН, доктора геолого-минералогических наук, заслуженного деятеля науки Российской Федерации, член-корреспондента РАЕН, известного специалиста в области вулканической геологии и геоморфологии.
Comments on the article by D.S. Tyagunov and A.F. Shestakov «Registration of low-frequency electromagnetic emission by a magnetomodulation sensor in laboratory experiments on the destruction of rock samples»
The commentary presents the results of the analysis of experimental data given in the article under discussion. The analysis revealed several serious inconsistencies and discrepancies, indicating the imperfection of the applied experimental methodology and measuring instruments. A discrepancy has been found between the stated capabilities of the measuring device and the quantitative characteristics of the recorded signal, which casts doubt on the reliability of the primary data Based on several simple physical models, the characteristics of the source of the recorded magnetic effect were calculated, showing that it is impossible to generate a magnetic field with the values given in the article under the described experimental conditions. An analysis of the results of publications on the measurement of electrical effects accompanying the loading of the sample was carried out. A comparison with data published in other sources was carried out, revealing a multiple (by several orders of magnitude) discrepancy between the magnetic field value given in the article under discussion and the data from similar experiments. It is shown that the connection between the recorded magnetic effect and the destruction of the sample is extremely unlikely. Recommendations and experiments on detection and identification of sources of the magnetic field observed during the sample destruction in a laboratory setup are proposed.
Copyright (c) 2026 А.Д. Коноплин, В.А. Щапов https://creativecommons.org/licenses/by-nc/4.0
Rotational-vortex geomorphology — a modified general term for the rapidly rotating planet Earth, and its variants for other Earth-like planets
It has been demonstrated that rotational-vortex geomorphology is not only a science but also the leading, longest-lasting, and most persistent global factor in shaping the rapidly rotating Earth. It manifested itself from the initial stage of Earth's growth as an accretionary planet, and the ellipsoid of the Proto-Earth was inherited from the growing core of a rapidly rotating counterclockwise spiral vortex that orbited the Sun. The vortex core, thanks to a complex, multilayered, and multi-faceted set of turbulent processes occurring there, transformed into a layered, rapidly rotating planet–Earth–composed of spherical shells. Rotation served as the primary and main global cause of dynamic shaping processes occurring in the lithosphere, as well as those associated with the planet's hydrosphere and atmosphere. A key consequence of the rotational effect and spiral vortices is their indirect influence on terrestrial shaping through the organic life they enabled, including humans. The origin of life is the active and complex interaction between lithospheric vortices and the vortex structures of the Earth's liquid outer core. The vortex structures of the liquid core have been and remain the generators of alternating electric and magnetic fields.
Copyright (c) 2026 И.В. Мелекесцев https://creativecommons.org/licenses/by-nc/4.0
On the inconsistency of the basic postulates of modern concepts of the formation and development of the Earth's lithosphere with the properties of natural structures. Part 1 — continental crust
It has been suggested that the causes of the crisis in geodynamics of the tectonosphere that has existed for the last decades are the unreality of the six known propositions that form the basis of plate tectonics, to which are added the property of constancy of the volume of the continental crust and an expanded understanding of actualism. From this perspective, the first part of the article analyzes objects on two scales: the structure of the sedimentary cover of the Greater Caucasus and its crust and lithosphere. The structures of the Caledonian Tien Shan, the Alpine Pyrenean-Provençal trough, and the Mesozoic Sikhote-Alin are also considered. The identified properties of the structures do not correspond to the studied positions: deformations are not concentrated at plate boundaries, no «accretionary prism» is observed in the folding, the thickness of the continental crust decreases during the development of structures, and the principle of «actualism» has been used incorrectly. To overcome the crisis in the geodynamics of the tectonosphere, it is proposed to abandon the use of unconfirmed theoretical positions of plate tectonics.
Copyright (c) 2026 Ф.Л. Яковлев https://creativecommons.org/licenses/by-nc/4.0
The potential of large-scale magnetic surveying using unmanned aerial vehicles in gold prospecting: the case of the Chulbatkan ore field
A comparison was made of the results of ground-based magnetic surveys and unmanned aerial vehicle surveys performed in 2020 and 2021 at the Chulbatkan gold deposit in the Khabarovsk region and its surrounding area. The analyses of the correlation between the total magnetic field induction vector and its local anomalies obtained from the two types of surveys in overlapping areas demonstrate their high consistency. The proportion of anomalies not detected by the aerial magnetic survey was evaluated. The influence of magnetic field smoothing at altitude on the results of its interpretation was analyzed in comparison with ground-based surveys. The experience of compiling a composite magnetic map based on both types of magnetic surveys for the Chulbatkan deposit area was examined. Methodological conclusions were drawn regarding the effectiveness of low-altitude surveys for various geological settings, considering the magnetic properties of the rocks, and the role of such surveys within the overall exploration complex was demonstrated.
Copyright (c) 2026 М.Ю. Носырев, А.Ю. Юрчук, Г.З. Гильманова, А.Ю. Песков https://creativecommons.org/licenses/by-nc/4.0
Using of global gravity models for modelling of rheologic in homogeneities in the crust and upper mantle
Gravity maps of Bouguer anomalies according to land and sea observations of scale 1,000,000 are compared with gravity anomalies in the satellite spherical EGM08_CBA_global_2190_2.5m model in territories of the Sea of Okhotsk and left-bank East Priamurye. Independent probabilistic-deterministic rheological interpretation of gravity anomalies in two systems of them description as a result of which the comparable models of spatial distributions of density differentiation (contrast) of the crust and a subcrustal mantle layers reflecting rheological states of geological media are received are executed. In both models rigid crystal blocks in the lower crust and zones of the lowered viscosity dividing them, corresponding to regional structures of stretching in the crust and subcrustal layers equally are reflected. The applicability of global spherical gravity EGM08 model for tectonic interpretation of regional anomalies Bouguer in scale M 1:1 000 000 is proved.
Copyright (c) 2026 А.М. Петрищевский https://creativecommons.org/licenses/by-nc/4.0
Middle permian terrigenous deposits of Laoeling-Grodekovo terrane (Southwest Primorye): lithology and paleogeodynamic nature
The results of the study and paleogeodynamic interpretation of the material composition of sandy rocks of the Middle Permian Barabash Formation of the Laoeling-Grodekovo terrane, located in the southwestern part of Primorye, are presented. The sandstones studied belong to greywacke and, in part, to lithic arenite. Sandstones are petrogenic, «first cycle» rocks that have undergone a single cycle of redeposition. The formation of deposits occurred as a result of the destruction of moderately weathered rocks in areas of denudation. Analysis and paleogeodynamic interpretation of the obtained mineral and geochemical data indicate that deposits accumulated in a basin within an active continental margin margin, most likely complicated by strike-slip movements along transform faults. The main source of the clastic material was the continental landmass — cratons and uplifted basement blocks composed of granite-metamorphic and, in part, sedimentary rocks containing ancient clastic components. Secondary sources were fragments of an ancient, deeply dissected marginal-continental magmatic arc composed of basic and ultramafic rocks.
Copyright (c) 2026 А.И. Малиновский https://creativecommons.org/licenses/by-nc/4.0
Abrasion coastal cliffs of Western Kamchatka
In northwestern Kamchatka, five types of abrasion coasts are distinguished between the Utkholok and Etolona Rivers. The predominantly abrasion subtype predominates in the areas of development of magmatic formations on the western coast of the Utkholok Peninsula, as well as on the Ovra and Omgon Capes. It is represented by steep slopes, wave-cut niches and abrasion terraces (benches). The abrasion-landslide subtype of coast is characterized by large landslides, the frontal parts of which reach the level of wave impact. An example is the landslide south of Cape Ovra. The abrasion-collapse subtype of coast was formed where rock strata dip steeply (at an angle exceeding 40–50°). This type of coast is typical for the areas of Cape Babushkin and the mouth of the Tochilo Creek. The abrasion-landslide-avalanche subtype of coast was formed in the area of differently deformed Cenozoic sedimentary rocks outcropping in the Tochilo section. The abrasion-denudation subtype of coast is developed in areas with gently sloping or horizontal rock strata in the north of the Tochilo, Maynach and Uvuch sections. Inactive portions of coastline are the abrasion-denudation high cliffs strongly vegetated.
Copyright (c) 2026 А.О. Мазарович https://creativecommons.org/licenses/by-nc/4.0
Thick ore crusts of the Sea of Okhotsk super-enriched in nickel
Ore crusts up to 20 cm thick dredged from a depth of 1500–1300 m in the eastern part of the Akademii Nauk Rise in the Sea of Okhotsk were studied. The main ore mineral is vernadite. The crusts contain an average of 32 % manganese and 11 % iron. They are extremely enriched in nickel and are hydrogenetic, according to the combination of features. The nickel content in samples, according to inductively coupled plasma mass spectrometry, reaches 1.3 % with an average value of 1.0 %, and point microprobe analyses yield 2.6 % with an average value of 0.9 %. Based on a summary of our own and published data, a central-southern nickel-promising region was outlined in the Sea of Okhotsk. The nickel content in hydrogenetic ferromanganese crusts and nodules of the region is comparable to that in cobalt-rich manganese crusts and polymetallic ferromanganese nodules of the World Ocean.
hydrogenetic ferromanganese crusts and nodules
Copyright (c) 2026 О.Н. Колесник, А.Н. Колесник, А.А. Карабцов, В.Т. Съедин, В.А. Рашидов, П.Н. Постнов, Р.Б. Шакиров https://creativecommons.org/licenses/by-nc/4.0
The maps of rock magnetic parameters of the precambrian base of the Voronezh crystalline massif: formation methodology and analysis results
The article discusses a method for summarizing data on the magnetic properties of the Precambrian basement rocks of the Voronezh crystalline massif, which was used to create maps of magnetic susceptibility and residual magnetization that reflect the spatial distribution of the magnetic properties of rocks from various structural and material geological complexes in the region. The creation of these maps required a systematic study of the magnetic properties of the basement rocks, which included statistical and correlation analysis of the data, as well as an assessment of the magnetic properties of individual age groups based on the representation of rocks from different lithological types. The resulting digital model of the spatial distribution of petromagnetic parameters is visualized as maps of magnetic susceptibility and residual magnetization. The spatial distribution of the magnetic properties of the rocks of the Precambrian basement of the Voronezh crystalline massif, in combination with new isotope-geochemical data on the age of the rocks, is an important source of information for understanding the geodynamic development of the region. The synthesized representation of density and petromagnetic data in a single GIS project effectively represents a petrophysical model of the crystalline basement, which opens up new possibilities for quantitative and complex interpretation of the magnetic and gravitational fields in order to create three-dimensional geological models of the deep structure of the region.
Copyright (c) 2025 О.М. Муравина, В.Н. Глазнев, А.А. Сотников, И.Ю. Антонова, О.С. Жидких https://creativecommons.org/licenses/by-nc/4.0
Paleomagnetic dating of early paleozoic coarse-grained strata of the Khan-Khukhei Ridge (Northwestern Mongolia)
Paleomagnetic studies of post-accretionary Early Phanerozoic coarse-clastic strata in the western part of the Khan-Khuhei Ridge in northwestern Mongolia were carried out. Based on high-temperature magnetization, a paleomagnetic pole was calculated with the coordinates Φ = −27.3° Ʌ = 96.4°, А95 = 3.5°, and paleolatitudes of formation of the strata – from 10° N to 15° N. The coordinates of the paleomagnetic pole are close to the coordinates of the Late Ordovician and Early Silurian paleomagnetic poles of Siberia and differ sharply from the coordinates of the Early and Middle Ordovician paleomagnetic poles of Siberia. This suggests the Late Ordovician-Early Silurian age of the coarse-grained strata. The time of emplacement of subvolcanic bodies that cut the coarse-grained strata gas been specified. They were intruded at the beginning of the Silurian, since they crosscut the coarse-grained strata, but are absent in the early Silurian rocks. The coarse-grained strata were rotated clockwise relative to Tuva and Siberia by an angle of about 20°. The rotation of the strata is not associated with compressional folding. It is likely that the strata were rotated together with the basement complexes during rifting. The formation of rift zones could be associated with the action of a hot spot, delamination of the lithosphere, or post-collisional collapse of the orogen.
Copyright (c) 2025 Д.В. Коваленко, М.В. Бузина, А.Д. Коваленко https://creativecommons.org/licenses/by-nc/4.0
Formation of a crator in the area of the well 022 at the Mutnovskoe steam-hydroterm field in 2023–2024 (Kamchatka)
In late November–early December 2023, a large crater measuring approximately 190×125 m formed in the area of well 022 at the Mutnovsky steam-hydrothermal field. At the end of August, field work was carried out at this site which included orthophotography in the visible and infrared ranges, measurements of the temperature field at different depths in the bottom part of the crater, and the description and selection of sediments displaced from the crater. The work carried out, together with a comprehensive study of multispectral satellite images, made it possible to establish the timing and mechanism of the formation of this funnels. The main geological event that led to the formation of this funnel was a large landslide into the bed of the nearest stream, which subsequently caused several large hydrothermal explosions due to the removal of a significant portion of the lithostatic pressure, the deposits of which spread around the funnel over an area of more than 100000 m2.
Copyright (c) 2025 А.А. Нуждаев, Р.А. Кузнецов, И.Е. Большаков, А.Н. Матвеев, В.О. Давыдова https://creativecommons.org/licenses/by-nc/4.0
Amphibole megacrysts in pyroclastic material from secondary eruptive centers of Kronotsky volcano
Here we present data on the morphology and composition of amphibole megacrysts found in pyroclastic material from two eruptive centers on the southern slopes of Kronotsky Volcano. The megacrysts, ranging in size from 1 to 8 cm, occur both within the matrix of volcanic bombs and as rounded lapilli in the form of single crystals or thier intergrowths. Compositionally, the megacrysts belong to the ferri-tschermakite–magnesio-hastingsite series with high Al2O3 contents (14.8–16 wt.%) and average magnesian index of Mg# = Mg/Mg+Fe2+ =0.67. The host volcanic bombs are low-K tholeiitic basalts (SiO2 = 49.32–50.50 wt.%, K2O = 0.24–0.27 wt.%, FeO/MgO = 1.7–2.1). In addition, the pyroclastic material contains xenoliths of olivine pyroxenites as well as coarse- and medium-grained amphibole–plagioclase intergrowths. Several hypotheses are proposed to explain the origin of this association, which is highly unusual for tholeiitic island arc basalts.
Copyright (c) 2025 Г.Н. Овсянников, Н.В. Горбач, А.Н. Рогозин https://creativecommons.org/licenses/by-nc/4.0
Application of coherent analysis in studying deep long-period earthquakes of Klyuchevskoy Volcano (Kamchatka, Russia)
Klyuchevskoy Volcano (Russia, Kamchatka Peninsula) has been in a state of almost continuous eruption since 2003. Forecasting its eruptions is still a serious scientific and technical problem. One of the promising approaches for solving it is the use of the SESL’09 seismicity assessment method. To identify predictive parameters based on this method, it is necessary to determine the most seismically active volumes of the environment beneath the volcano. Klyuchevskoy Volcano is one of the sources of most intense sources of volcanic deep long-period earthquakes in the world, which are recorded at the crust-mantle boundary in a depth of 20–40 km. As a rule, this zone is considered as a single structure. In this study, based on the coherence analysis of waveforms of deep long-period earthquakes, it is shown that the mechanism of their occurrence is different for depths of ~20 km and ~28 km, which allows us to identify two different seismogenerating volumes at depths of 20–25 km and 26–34 km.
Copyright (c) 2025 А.А. Шакирова, П.А. Малютин, В.А. Салтыков, А.С. Чемарев https://creativecommons.org/licenses/by-nc/4.0
New data on fahlores of the Vilyuchinskoye ore occurrence (Southern Kamchatka)
Представлены результаты исследования типоморфных характеристик минералов группы блеклых руд Вилючинского золото-серебро-полиметаллического рудопроявления, расположенного в Южно-Камчатском горнорудном районе. На основании изучения особенностей химического состава с помощью сканирующей электронной микроскопии и электронно-зондового микроанализа установлено, что блеклые руды представляют собой сложные соединения, отличающиеся значительными вариациями и количественными соотношениями слагающих их химических элементов. Изученные блеклые руды образуют следующие минеральные ассоциации: блекловорудно-кварцевую, сульфидно-блекловорудно-кварцевую и блекловорудно-золото-теллуридно-селенидно-кварцевую. Блекловорудно-кварцевая ассоциация сложена непосредственно минералами — блеклые руды и кварц; в сульфидно-блекловорудно-кварцевой выделяются халькопирит, пирит, галенит, халькозин, блеклые руды и кварц; блеклые руды, теллуриды Au, Ag, селениды Ag, Pb и кварц составляют блекловорудно-золото-теллуридно-селенидно-кварцевую минеральную ассоциацию. По соотношению основных минералообразующих элементов выделены три минеральных разновидности: теннантиты, тетраэдриты и голдфилдиты, а также две междувидовых и семь внутривидовых разновидностей. Полученные данные могут быть использованы для выяснения закономерностей эволюции химического состава рудогенерирующих растворов и расшифровки физико-химических условий образования руд.
Copyright (c) 2025 К.О. Шишканова https://creativecommons.org/licenses/by-nc/4.0
Possibilities of using multalt computer technology for regional assessment of prospective areas based on a complex of geological features
A probabilistic forecast for detecting target objects for study was developed based on a set of geological data that qualitatively characterizes the structure of the study area. This forecasting methodology, implemented using MultAlt computer technology, involves creating grids with a discrete distribution of qualitative geological features, the compilation of training tables of expert scores based on available a priori geological and geophysical information and experience in geological exploration in the region. A clear advantage of such predictive models is the ability to take into account various expert opinions regarding the state of a current qualitative feature. Expert geologists intuitively evaluate the states as scores presented in training tables and distributed in varying ratios. Based on previously conducted geological and geophysical studies within the Okhotsk-West Kamchatka region, a formalized forecast of oil and gas potential was made using a set of specially prepared qualitative geological features. The results are presented in the form of probability maps promising for hydrocarbon.
Copyright (c) 2025 Д.Ф. Калинин, Н.В. Большакова, А.С. Егоров, В.В. Глазунов https://creativecommons.org/licenses/by-nc/4.0
Sedimentation environment in the Tatar Strait of the Sea of Japan
High-resolution seismoacoustic data were obtained in the central Tatar Straight of the Sea of Japan in 59-th cruise of Research Vessel «Akademik M.A Lavrentiev» conducted as a part of the international «Sakhalin Slope Gas Hydrates» project in the summer of 2012. The data was used to identify types of reflecting signals echotypes, map their distribution fields, and determine sedimentation environments. These environments include sedimentation with weak or no bottom currents on the eastern side of the strait, underwater erosion and redeposition by bottom currents on its western flank; transportation and deposition of sediments by bottom currents and turbidite flows with the formation of conturite drifts and sedimentary waves in the central part of the strait. An assumption has been made about the direction and relative velocities of currents that influenced sediment accumulation on the western side of the strait and in its central part.
Copyright (c) 2025 Д.Д. Рукавишникова, К.А. Дозорова, Б.В. Баранов https://creativecommons.org/licenses/by-nc/4.0
Lithology and formation settings of the Pospelovo Formation in Southern Primorye: new data
The results of the study and paleogeodynamic interpretation of the material composition of sandy rocks of the Early-Middle Permian Pospelovo Formation, developed on the Muravyov-Amursky Peninsula (Southern Primorye), are presented. The studies showed that, in terms of their parameters, sandstones are mainly lithic arenites and arcoses, which formed by the erosion and redeposition of significantly weathered parent rocks of the feeding areas. Interpretation of all the data obtained indicates that in the Early to Middle Permian, sedimentation occurred in basins in a passive continental margin. The main source of the clastic material was the continental landmass – uplifted basement blocks composed of acidic granite-metamorphic complexes and, partly, sedimentary rocks enriched with ancient clastic components. The presence of a small amount of femic heavy minerals in the sandstones also indicates the participation of areas of erosion of basic and ultrabasic rocks.
Copyright (c) 2025 А.И. Малиновский https://creativecommons.org/licenses/by-nc/4.0