Abstract In this work we investigated the indicators of NW-trending hidden faults in the Priamurye region. Four major fault zones and a series of lower-rank faults were mapped, which have been revealed from the relief lineaments, magnetic anomalies, and arranged earthquake foci sequences. In the region, the NW-trending faults control the block divisibility of the upper part of the lithosphere and appear

Abstract The paper presents the first findings of paleomagnetic studies on Middle Jurassic sedimentary rocks of the Elgon Formation of the Ulban Terrane from the coastal outcrops along the Ulban Bay (53.5° N, 137.7° E). Demagnetization yielded a ChRM component of the pre-folding age. No inclination shallowing effect for the ChRM vector was revealed in sandstone specimens of the Elgon Formation. The

Abstract A continuous record of paleogeographic events in the Shantar islands since the end of the Pleistocene has been obtained by a multy-proxy study of the stratigraphy of the blanket peatland. The biostratigraphical studies included botanical, diatom, and pollen analyses. The age-depth model has been developed using seven radiocarbon dates. Data on the development of the environment have been obtained

Abstract Numerous silicate, Fe-oxide, and Cu–Au–Ag microspherules are found in Fe ores and pyroclastic rocks of the Kostenga deposit, Lesser Khingan (Far East of Russia). The silicate spherules contain immiscible Fe and Si glasses, vapor voids, and mineral inclusions. The Fe-oxide spherules host magnetite with a small amount of ilmenite and Fe-rich silicate glass. The Cu–Au–Ag spherules contain inclusions

Abstract Carbonaceous beds have been studied in the Cretaceous paleo-oceanic deposits of Eastern Kamchatka; their origin relates to the anoxic oceanic events. In the carbonaceous rocks, the contents of trace elements and noble metals: Ba, Cu, Ni, Zn, Mo, V, U, Y, Au, rare-earth elements and platinoids are increased compared to host jaspers and limestones. In particular, in ashed carbonaceous rocks

Abstract A structural interpretation of the first Re–Os dating of pyrite and arsenopyrite from the Malinovsky gold deposit is given. Comparison of the obtained data and the known ages of ore-bearing granitoids from the ore field made it possible to determine the age of mineralization as 100–90 Ma. This age corresponds to the time of completion of the Albian–Cenomanian geodynamic setting of the transform

This article presents U–Th–Pb and Lu–Hf detrital zircon isotope data, as well as whole-rock Sm–Nd isotope data on metasedimentary rocks from the eastern part of the Tukuringra Terrane. Our analyses show that the zircons in metasedimentary rocks are mostly early Mesozoic. The Early Mesozoic, Early Paleozoic and Neoproterozoic zircons are predominant and Early Precambrian zircons are almost absent in

Abstract Problems of the origin and tectonic structure of the South Verkhoyansk synclinorium are discussed. It is suggested that in the Late Paleozoic the South Verkhoyansk basin inherited the structure of the Sette-Daban rift graben arranged as a submarine valley across the Verkhoyansk passive margin. Lateral movements of the Okhotsk indenter during the Late Mesozoic orogenic events led to transformation

This paper reports original geochronological and trace-element data on basalts from the dredging sites 2776 and 2764 located in the southern part of the Central Fault in the Philippine Sea. The studies showed that the basalts from st. 2776 demonstrate chemical features of mid-ocean ridge and ocean island-arc basalts (N-MORB+OIAB), while basalts from st. 2764 show E-MORB+OIAB signatures. A comparative

U–Pb zircon dating of felsic volcanic rocks from the Konachan Complex (Algan Mountains, northwestern Koryak Highland) confirmed their Late Miocene age (34.6 ± 0.5–38.8 ± 0.4 Ma, Priabonian). It is shown that these rocks are represented by moderate-potassium peraluminous (ASI = 1.23–1.30), moderate- and high-Mg varieties, frequently with high Cr and Ni contents. The Sr, Y, and Yb contents are similar

Abstract The results of biostratigraphic study based on the radiolarian analysis of the rhythmically-layered terrigenous deposits developed in the islands of the Rimsky-Korsakov Archipelago (Peter the Great Bay) are presented. These deposits are most similar to medium-grained turbidiites (according to [21]). In the study region, the development and stratigraphic subdivision of the Upper Triassic and

Abstract For the first time, this paper presents the distribution of gases (CO2, hydrocarbon C1-C4, H2, He) in 39 gas samples in bottom sediments from 19 gravity cores located in the southwestern sub-basin of the South China Sea (known as Bien Dong). The surface sediments in the studied area are mostly clay and silty clay (mud). In general, the concentration of methane varies in a wide range of 0.5–440

Abstract The Taezhny is a silver with gold (Au : Ag = 1 : 100) vein deposit with a pronounced mineralogical and geochemical selenium ore specialization. The deposit is located in the eastern part of the Sikhote Alin Orogenic Belt, 700 km north of Vladivostok. Similarly to the Mexican Guanajuato deposits typical of the Pacific region, the position of the described ore-bearig area in the region is governed

This paper reports geological–structural and mineralogical data on the relationships of Paleozoic ore veins with Carboniferous and Mesozoic rocks at the Kubaka gold–silver deposit in the Omolon cratonic terrane. The presented observations are inconsistent with an Upper Carboniferous upper age limit of the deposit, which was inferred by Akinin et al. (2020) on the basis of isotope–geological studies

Abstract The Cretaceous fossil flora in deposits of the Okhotsk–Chukotka volcanic belt is drastically different in systematic composition from the paleoflora of similar ages in deposits of the Northeast Asian coastal lowlands and inland depressions. In the volcanic burials, paleoflora features are the most evident in the Chaun flora found in the Pegtymel trough in the Central Chukotka region and described

Abstract he Paleocene–Eocene sedimentary complex is most widely developed among the sedimentary cover deposits of the Magellan Seamounts. It is composed of pelagic (nanoforaminiferal) and reef limestones, edaphogenic breccias and volcanoclastic rocks. The most widespread pelagic limestones form narrow (0.5–1.5 km) and extensive (up to 20 km) ribbon-like bodies that cover the upper parts of the slopes

Abstract The U–Pb dating of zircons from two samples taken in the stratotype sections of the Middle Permian Gizhiga Formation in the Omolon Massif has been carried out for the first time. Weighted average ages of 266 ± 2 and 265 ± 3 Ma taking the error into account are consistent with the Capitanian age calculated previously by paleontological determination. The observed detrital zircon population

This paper reports the geochemical, U–Pb geochronological, and Sm-Nd isotopic–geochemical data on granites of the Medvedka Massif in the northern part of the Nora–Sukhotino terrane. It has been found that these granites have an age of 378 ± 3 Ma. They contain ferruginous silicates, have high iron index (FeO*/(FeO*+MgO)), low concentrations of Al2O3, CaO, MgO, high contents of Nb, Ga, Y, a deficiency

Abstract The original results of a study of the composition of terrigenous rocks of the Early Silurian Kordonka Formation of the Paleozoic–Early Mesozoic Laoeling–Grodekovo Terrane (southern Primorye) are considered. The aim of the study was to interpret the paleogeodynamic setting of the rocks of the formation and to determine the type and the composition of the parental rocks of the source areas

Abstract The mineral composition of the heavy subfraction from surface sediments of the Sea of Okhotsk has been studied using two detailed profiles (the Magadan-Kuril Islands and the Shantar Islands-Central part of the Sea of Okhotsk) and data from the Sakhalin Gulf. The obtained data have been analyzed by the methods of multivariate statistics, which allowed us to identify the main associations of

Abstract We analyze and generalize new data inferred from the geological, geochronological, and metallogenic studies performed in recent decades on igneous rocks of the Iorokhan gold-bearing complex in the eastern Bureya Massif. It is shown that four phases are determinative of the structure of the Iorokhan complex of minor intrusions whose rocks are referred to hypabyssal and subvolcanic intrusive

Abstract The brief results of integrated research in the southern part of the Tatar Strait and the northern part of the Sea of Japan obtained during the 85th cruise of the R/V Akademik M. A. Lavrentyev are presented. The characteristics of the bathymetric, gravimetric, magnetometric, hydrological, lithological, microbiological, and gas-geochemical studies are given. The bottom topography has been refined

Abstract Based on the results of correlation of the geoelectric and density sections constructed using three-dimensional inversion of three profiles located in the southern Sikhote Alin, the distribution regularities were revealed in the electric and density parameters, the relationships between them were established, and new data on the crust and upper mantle structure of the region were obtained

Abstract The results of integrated studies in the southwestern part of the Sea of Okhotsk obtained during cruise 74 of the R/V Akademik M.A. Lavrentiev in 2016 are presented. Gas hydrates, carbonate crusts and nodules in bottom sediments and more than 100 gas flares in the water column were recognized. Great attention has been paid to the gas composition of the water column and bottom sediments. Anomalous

Abstract The South Okhotsk Sea province, which includes the Sakhalin, Kunashir, Iturup, Urup islands and surrounding sea areas, comprises numerous occurrences of rare, noble metals and other mineralization, as well as petroleum fields, gas hydrate accumulations, and, locally, active emission of water–hydrocarbon gases. The occurrences and deposits of solid, liquid, and gaseous mineral resources are

Identification of magma sources and their role in the origination of basaltic magmas still remains one of the fundamental petrological problems. Based on new comprehensive isotope–geochemical and mineralogical data, the contribution of a pyroxenite mantle source was recognized for the first time for Oligocene basalts in the northern part of the East Sikhote Alin volcanic belt. The most important indicators

Abstract The proposed complex Parameter of River Network Self-similarity (PRNS), which is a combination of the exponents in the equations for distribution of channel lengths, the fractal dimension of channels, and the fractal dimension of points of change of the order of the channel, matches neotectonic movements more accurately. A comprehensive analysis of the self-similarity of the southern Sikhote-Alin

Abstract Using the generalized data of the seismic exploration studies carried out in the Aldan-Maya sedimentary basin, the choice of the seismostratigraphic model has been validated and the transversal and longitudinal sections have been constructed that allow understanding the features of the structure of the sedimentary cover and refining the basin boundaries. Based on the seismic sections and the

Abstract Original data on the isotope and chemical compositions of mineral springs, cold ground and surface waters, as well as hydrogenic deposits of the Antonovsky manifestation of hydrosulfuric mineral waters (the coast of the Tatar Strait, Sakhalin Island), are presented. The data on the contents of oxygen and hydrogen isotopes in ground and surface waters, as well as the volumetric activity of

Abstract This paper presents the results of a study of the distribution of major, trace, and rare-earth elements in the terrigenous rocks, wall-rock metasomatites, and ore zones of the orogenic Malo-Taryn gold deposit (Verkhoyansk-Kolyma folded area , Northeast Russia). An important role in the formation of metasomatites and ore zones was played by hydromicatization, carbonatization, sulfidization

The Sikhote-Alin orogenic belt is a key area for understanding the evolution of the lithospheric plate interaction in the East Asian paleocontinent margin. At the same time, only limited and fragmentary precision isotope–geochemical and geochronological data are available for this region. New age data on the Early Paleogene magmatism supplement the available material and substantiate a specific Middle

Abstract The materials of deep seismic studies carried out on the 1-SB reference geophysical profile and the areal interpretation of the seismological data obtained in the Trans-Baikal part of the Central Asian Fold Belt are presented. It is shown that longitudinal and transverse waves were recorded from the reference boundaries within the crust and the Moho surface in the Trans-Baikal region using

Abstract This paper presents the results of studies of the main factors that are responsible for the formation conditions and localization of oil and gas deposits within the Cenozoic sedimentary cover and Pre-Cenozoic granite basement of the Vietnamese shelf. Our structural–tectonic model of the Cuu Long Basin allows the identification of the formation conditions of regional and local structures with

Abstract X-ray diffractometry, X-ray fluorescence, and ICP-MS have been used to study the phase and elemental composition of the thermal coal from the Pavlovsk brown coal deposit and their ash-forming compounds. The results of the spectral analysis methods were combined with the data of thermal gravimetry, elemental analysis of OM, and scanning electron microscopy. The metal-bearing potential of the

Abstract New petrogeochemical data were used to determine the conditions of the formation and tectonic setting of volcanic rocks of the Lake Udyl’ area. These rocks were compared with similar rocks in the region. The volcanic rocks of the Lake Udyl’ area are subdivided into two genetic types: (1) within-plate oceanic volcanic rocks ascribed to the accretionary volcanogenic–siliceous complex (Titho

Abstract Based on a detailed bathymetric map of the southeastern part of the Magellan Seamounts created using the results of multibeam echo sounding, a lineament analysis of the seafloor relief was performed, linear landforms were distinguished and their azimuths were measured, and a rose diagram was constructed showing the lineament direction in the area. Models of the deep and subsurface deformation

Abstract The first study results on foraminifera from the Permian–Triassic boundary deposits in the southern Verkhoyansk region (the lower part of the Nekuchan Formation, Suol section located in the basin of Setorym River, a tributary of the East Khandyga River) are presented. The studied foraminifera constitute a novel group for this section and have not been used in paleontological-stratigraphic

AbstractA combination of laser diffraction and wet sieving through a nylon screen with a 0.1-mm mesh has been suggested for the particle-size analysis of silty bottom sediments from estuarine and coastal sea areas. The necessity of individual determination of sand fractions even in case of the technical ability of the device to analyze the content of coarse particles to 2 mm in size is shown. This

AbstractBased on the results of magnetotelluric soundings carried out in the southern part of the Sikhote Alin Fold System in the frequency range from 10 kHz to 0.001 Hz, the geoelectric section was constructed down to a depth of 150 km. The electrical parameters have been obtained and the crust and upper mantle structure has been studied. The crust has a high resistivity ranging from 1000 to 20 000

AbstractGeological, mineralogical–petrographic, and geochronological studies (U/Pb, Rb/Sr, and Ar/Ar isotope dating) of igneous complexes of the Dalat Zone identified two stages, which reflect a change in the geodynamic regime. The first, Late Jurassic, stage corresponded to a suprasubduction setting with formation of volcanic sequences of the Deobaoloc complex: calc-alkali basaltic andesites, andesites

AbstractThe detection of tectonic fracturing zones in the form of hidden faults, which are not exposed at the surface but are capable of generating intense seismic oscillations and causing hazardous geological phenomena, is a vital problem to be solved in the Priamurye region. We propose a comprehensive approach following which the earthquake migration data are taken as a basis for the detection of

The mineral composition of ferromanganese crusts from Belyaevsky Volcano in the Central Basin of the Sea of Japan has been studied. The crusts have diverse structures and a complex polymineral composition. Along with the previously known todorokite, birnessite, manganite, pyrolusite, and vernadite, we determined rhodochrosite, quenselite, manganosite, hetaerolite, manganotantalite, and tungomelane

AbstractNoble-metal mineralization of the Paleocene explosive structures of the Taukha terrane in Sikhote-Alin is ascribed to the gold–palladium–platinum type. It occurs in igneous rocks, fluidolites, and rodingites. The mineralization is unusual in the presence of so-called “cupriferous gold” in association with minerals of Ni, Sb, and S, native elements, disordered solid solutions, and intermetallic

AbstractPetrogeochemical and geochronological studies were conducted on the main varieties of granitoids from the Sedelga and Berezovsky batholiths in the eastern Bureya continental Massif of the Central Asian Fold Belt. SHRIMP-II U–Pb zircon dating of granitoids constrained the time of formation to the Late Triassic and Early Jurassic between 208 to 193 Ma. Our studies revealed that the batholiths

AbstractThe activity of polyvalent elements in the geochemical processes is to a considerable extent determined by the valence state. A change in the valence is dependent on many factors, but the redox conditions of the medium where magma is generated are considered the main factor. The ratio between divalent and trivalent iron in magmatic rocks is a reliable and an accessible indicator of the redox

AbstractThe results of P-wave velocity measurements in the basement and sedimentary cover rocks of the submarine Vityaz Ridge and surrounding morphostructures, used for age correlation of the geological complexes, are presented. The numerical values of the seismoacoustic parameter were obtained under laboratory conditions by direct measurements of the samples collected in the area of the Central Kuril

The Middle (?) to Late Paleozoic ophiolite association of West Chukotka comprises the large Aluchin, Atamanov, and Gromadnen–Vurguveem mafic–ultramafic massifs, which are spatially associated with Late Paleozoic volcanic rocks of the Yarakvaam terrane. This paper is devoted to the dikes of the Gromadnen–Vurguveem massif, which form two spatially isolated complexes: “dikes 1” and “dikes 2.” Both complexes

AbstractThe paper presents the results of U-Pb and Lu-Hf isotope studies of detrital zircons from the terrigenous the Lan 410 Ma (Lower Devonian), Terrane in the eastern part of the Mongol-Okhotsk fold belt. The lower age rocks limits are for the Nivakh formation ~ for the Verkholan series ~332 Ma (Mississippian), for the Ugokhan series ~239 Ma (Middle Triassic). The evidences were obtained for the

This paper presents new data on rocks dredged from the Hahajima Seamount during the cruise KH03-3 of R/V Hakuho-Maru in 2003. It is shown that the seamount is a tectonically displaced block of the Earth’s crust composed of island-arc ophiolites. The basement of the ophiolite complex is made up of highly depleted mantle residue (dunites and harzburgites). Upward, they grade into cumulate lherzolites

AbstractThe gravity field stresses caused by density inhomogeneity of the Earth’s crust in the Central Kuriles area are calculated. The general spatial variation trend of the stress field and its local perturbations via structural and density differentiation of the Earth’s crust are revealed. We conclude that areas with gravitational instability exist within the crust. The hypocenters of the Simushir

The scale and age of extreme hydrological events that have been manifested over the past 2000 years on the coast of Valentin Bay is established based on stratigraphic study and radiocarbon dating of different facies deposits. The deposits of four major historical tsunamis (1993, 1983, 1644, and the 12th century) and a paleo-tsunami, which occurred between 1700–1800 cal yr BP . BP, were found. Sedimentation

AbstractA model of the geological evolution of the Sea of Okhotsk is presented based on data from radioisotope age determinations and the mineral and isotope-geochemical composition of Late Mesozoic–Cenozoic volcanic rocks. We discuss the probable interrelationship between gas geochemical manifestations of gas fluxes with anomalous methane concentrations and the formation of gas hydrates, along with

AbstractThis paper presents geochemical, microprobe, paleomagnetic, and rock magnetic data from peat accumulated over the past 10 000 years in the area between the Khor and Kiya rivers (Khabarovsk krai). A horizon ranging in thickness between 75 and 100 cm with elevated concentrations of Ni, Zn, Bi, and Se is identified as a result of comprehensive studies. Magnetite and carbon spherules, as well as

Based on statistical processing of gravity anomalies and tectonic interpretation of 3D distributions of density contrast in the crust and upper mantle of Southeast China, new features of rheological layering of the tectonosphere are revealed. Relations of near-surface geological structures with a deep tectonosphere structure in this region are defined. New data on deep relationship of lithospheric

The most studied sections of the Triassic sequences in the lithotectonic zones along the Mongol–Okhotsk fold system from Eastern Transbaikalia to the Sea of Okhotsk are described. Changes in the composition, thickness, and characteristic biota are traced. Transgressive and regressive evolution stages are defined. The presented modern ideas on the geology of this region can serve as a reliable basis

AbstractConsideration is given to the nature of mafic–ultramafic bodies in the southeastern part of the Aldan-Stanovoi Shield using the Kun-Manie ore field as an example. These bodies played an important role in the formation of the Kun-Manie sulfide copper–nickel deposit as conduits of sulfide-bearing magmas. A detailed mineralogical and geochemical study with interval sampling was carried out on

The 190Pt-4He age of isoferroplatinum from andesitic fluid-explosion breccias (fluidolites, a new type of platinum-bearing rock) of the Poperechnoye deposit (Malyi Khingan, Russia) was estimated as 125 ± 21 Ma. This age correlates well with peak magmatic activity in the eastern Central Asian orogenic belt caused by upwelling of slab-window asthenosphere in a transform continental margin setting.

AbstractPetrographic, mineralogical, and geochemical analyses were conducted on Cenozoic sandstones from the Dunhua Basin, which located in Dunhua-mishan fault zone of northeast China, to investigate the provenance of the sediments, as well as the weathering intensity and tectonic setting of the source region. Petrographic data indicate that average quartz-feldspar-lithic (Q-F-L) proportions in the

AbstractGeochronological dating was performed on the detrital zircons of 20 sedimentary rock samples from the Khabarovsk, Samarka, and Zhuravlevka–Amur terranes in the northern Sikhote-Alin Orogenic Belt to establish that (1) the isotopic 206Pb/238U ages of the youngest detrital zircon populations of two sedimentary rock samples from the Gorin (K1b) and Pioner (K1b-v) formations, as well as one sample

AbstractThe results of gas-geochemical studies of the Chaun Depression and the Ayon sedimentary basin of the East Siberian Sea are presented. The natural gas composition in rocks, gas manifestations, and bottom sediments is determined. The indicators of the molecular mass of hydrocarbon fractions and weight concentrations of individual hydrocarbons, in which ratios are of correlation-genetic significance