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

Integrated geological and mineralogical–geochemical study of the ores of the Sredne-Golgotay gold–bismuth deposit using high-precision analytical techniques allowed new data reflecting the typical features and nature of the Au–Bi–Te mineralization. The ores of the Sredne-Golgotay deposit were formed at different stages of gold-forming process and comprise widespread minerals of the Bi–Te–S and Pb–Bi–Sb–S

AbstractNew data are obtained on the age of the epithermal gold-silver mineralization of the Kubaka deposit (Omolon Massif, Northeast Russia). Our geological observations in the open-pit mine of the Zokol zone of the deposit allow us to conclude that the mineralization formed between the eruptions of Upper Devonian ore-hosting volcanites of the Kedon series (zircon U-Pb age ~ 370 ± 2.5 Ma, SHRIMP)

AbstractDitrital zircon U-Pb and Lu-Hf isotopic data are reported for metaterrigenous deposits of Dzhagdy Terrane in the Mongol–Okhotsk Fold Belt. The youngest zircon populations in metasedimentary rocks of the Dzheskogon and Nekter formations is concluded to be of the Middle–Late Triassic and Early Jurassic Age, suggesting that the formations are Early Mesozoic and not Carboniferous, as was previously

AbstractA review of the biostratigraphic division of the Upper Carnian substage of the Boreal paleobiogeographic Realm by ammonoids is presented. The history of identifying the yakutensis ammonoid zone of the Upper Carnian in Northeastern Russia and the evolution of the views on its volume and paleontological characteristics are considered. The systematic composition and stratigraphic distribution

AbstractThe Sikhote-Alin Orogen in the southeast of Russia is a collage of geological terranes of various age and tectonic origin, which formed along the East Asian continental margin as a result of the Jurassic–Early Cretaceous subduction of the Pacific oceanic plates. The Jurassic Samarka accretionary complex (AC) and the Early Cretaceous Zhuravlevka turbidite basin in the southern part of the orogen

AbstractNumerous phosphorite occurrences are located among the Riphean–Early Cambrian rocks of the Khingan Group (Lessr Khingan, JAO). They are associated spatially and genetically with uranium, iron, and manganese ore occurrences. The phosphorites of the Gremuchy occurrence are enriched in rare-earth elements (REE) and yttrium (up to 813.58 g/t), uranium (up to 52.23 g/t), and gold (up to 17.03 g/t)

AbstractThe first paleomagnetic and petrochemical data on the Lower Cretaceous sedimentary rocks of the Komsomolsk Series from the Zhuravlevka–Amurian turbidite paleobasin are presented. The rocks are collected in coastal outcrops of Sakhalin Bay (54.09° N, 140.05° E). The studies reveal that (1) the petrochemical characteristics of the sedimentary rocks of the Gorinskaya and Pionerskaya formations

AbstractThe quantitative processing of gravimetric data is performed and the 3D density model is calculated for the southern part of the Russian margin of Eurasian continent. Based on the density model, new patterns of disjunctive tectonics at different depth levels are revealed and the position of the region at the global tectonic level is shown. It is established that the transition zone is an integrated

AbstractThe geodynamic setting of the Agnie–Afanas’evskaya auriferous rotational structure, genetically related to a transtensional left-lateral duplex zone which was formed against the background of the regional roughly north–south lateral contraction (transpression), is discussed. Regional dislocations are accompanied by local dislocations caused by internal stresses, which account for the details

AbstractThe paper reports the results of 40Ar/39Ar geochronological studies of the muscovite–quartz–albite metasomatites of the ore bodies and host rocks of the Albyn deposit located in the Selemdzha–Kerbi structural zone of the eastern part of the Mongol–Okhotsk Fold Belt. To a first approximation, the age of the hydrothermal ore process responsible for the formation of the Albyn deposit can be estimated

AbstractBased on the data of relief analysis, the gravity and magnetic anomaly axes, earthquake foci sequences, and Vp/Vs ratio values, tectonic fracturing of the lithosphere is studied and tectonic submeridionally and sublatitudinally oriented fracturing zones are distinguished in the Priamurye region. Separate segments of extended submeridional and sublatitudional fracturing zones are evidenced from

AbstractThe analysis of features of the geological structure of the Adycha gold placer region shows that flat structures of the early collision stage control the setting of the ore fields. The ores are similar to host rocks in the main components, lithofile trace elements, and REEs. The features of the trace-element pattern and indicative ratios agree with the suggested metamorphic origin of the main

AbstractMagnetotelluric soundings (MTS) are carried out in a broad frequency range from 104 to 10–3 Hz at a total of fifty-five sounding sites spaced about 5 km apart along the profile Dal’nerechensk–Roshchino–Plastun across the strike of the Sikhote Alin Orogenic Belt (SAOB). Based on the results of data interpretation, the crust and upper mantle geoelectric section is constructed down to a depth

AbstractThe evolution of the hydrothermal system forming the Bazov gold-ore deposit is traced by the data on the composition and properties of the fluid inclusions within the veined quartz. The gold-bearing quartz veins were formed under a moderate decrease of temperature from 290 to 230°C and considerable decrease of pressure from 0.75 to 0.25 kbar. The pressure drop was accompanied by the volume

AbstractThe clay minerals in the Upper Pleistocene sediments from DSDP Hole 478 (a drilled depth of 464 m) located in the central area of the Guaymas Basin, Gulf of California, are studied. The composition of the clay minerals and their quantitative proportions in natural mixtures are determined by modeling of X-ray diffraction patterns for oriented specimens of finely dispersed particles. The terrigenous

AbstractBased on a compilation of the vast literature, we typify the peculiar mantle-derived adakitic volcanic rocks in the Sea of Okhotsk, Kamchatka, and Bering Sea regions. The low-silica (LSA) and high-silica (HSA) types are distinguished in each region. The prevailing adakite type corresponds to the bimodal basalt–andesite series in the Kamchatka region and the basanite–dacite series in the Bering

AbstractThe typical rocks composing the base of the sedimentary cover of the guyots on the Magellan Seamounts are described. The upper part of the volcanic basement of the guyots is overlain by Aptian deposits of shallow reef ecosystems represented by terrigenous (beach) and organic-chemical (coral, shell-and-detritus, and oolitic) carbonate rocks. These deposits encircle the western part of the Fedorov

AbstractThe results of measurements of the electrical properties of rocks and induced polarization surveying are analyzed for three gold-ore deposits including the Bamskoe, Berezitovoe, and Pokrovka in the Upper Priamurye region. The spatial correlation is shown between mineralization zones and contrasting resistivity boundaries mapped within the gold-ore fields. The assumption is validated that the

The article presents the results of comprehensive geological and geochemical study of the sedimentary rocks of the Upper Paleozoic Shazagaitui and Zhipkhoshi formations filling the upper part of the Chiron Basin, as well as U–Pb geochronological and Lu–Hf isotopic studies of zircons from these formations. The geochemical features of the terrigenous rocks of the Shazagaitui and Zhipkhoshi formations

AbstractThe Zorin and Chingandzha floras significantly differ in their systematic composition, but they are buried at the same stratigraphic level. On this basis, they are considered to be of the same age and are assigned to the Turonian–Coniacian period. The revealed features of the lithological composition of the plant-bearing deposits, their sequence, and the composition of the overlaying volcanic

AbstractIn southeastern Khabarovsk krai, in the basin of the Tumnin River, the foraminifera complex containing the characteristic species Ammosiphonia beresoviensis (Bulatova), represented by exclusively agglutinated shells, is revealed for the first time in sections of Albian deposits. In terms of composition and structure, the complex is closest to the associations widespread in the Albian in the

AbstractIn recent years, the satellite altimeter technology allows to enhance the marine investigation in any area. Up to now, many scientific studies have attempted to improve the accuracy and resolution of altimeter-derived gravity anomalies and have produced a gravity grid with interval of 1' × 1' for most the oceans all over the world. However, this gravity anomalies are not very high accuracy

AbstractThe paper presents new geological, petrological, and geochemical data on the dunite–clinopyroxenite–gabbro massifs of the Tamanvayam area. The time of formation of the intrusions is specified using U–Pb zircon dating. The Machevna Massif is mainly composed of gabbroids and clinopyroxenites, which are related by gradual facies transitions and intruded by amphibole gabbro, leucogabbro, and monzogabbro

The Transbaikal sector of the Mongol–Okhotsk orogenic belt displays a well-consistent geochemical and metallogenic zoning. The axial zone of the belt, which is controlled by the Mongol–Okhotsk suture zone from the north, is composed of reduced ilmenite-series rocks. Tin, tungsten, and rare-metal deposits and occurrences previously distinguished by S.S. Smirnov as a rare-metal belt are confined to the

AbstractThe lithochemistry potential for comparison and correlation of terrigenous deposits and paleoreconstructions of facies sedimentation settings is studied on the example of the Komsomolsk section. The completed works and analysis of the first data on the contents of chemical components and values of lithochemical modules of the Upper Jurassic–Lower Cretaceous rocks making up the Komsomolsk section

AbstractThe East Sikhote Alin volcanic belt (~1500 km long) is commonly regarded as a tectonomagmatic structure formed in the Late Cretaceous in a subduction environment, which was followed by the destruction of the oceanic slab and active asthenospheric diapirism in the Cenozoic. However, the nature of the lateral zonality of the Late Cretaceous volcanic complexes, which is distinctly expressed in

AbstractGeological data and about 300 precision geochronological and geochemical determinations are analyzed to identify the Albian–Cenomanian continental-margin orogenic belt and simultaneous igneous province of Pacific Asia. The orogenic belt represents a newly formed region of continental lithosphere that resulted from the deformation of mainly Jurassic–Early Cretaceous epioceanic terranes. The

AbstractThe results of comprehensive (geological, geochemical, geochronological, and petro- and paleomagnetic) study of the Aptian–Albian rocks of the Kema Terrane and the northeastern Udyl segment of the Kiselevka–Manoma Terrane are presented. The obtained results suggest that the studied volcanogenic–terrigenous complexes of rocks formed in a suprasubduction zone at about the same time (early Albian

AbstractThe Itmurundy zone of the northern Balkhash area is a Pacific-type orogenic belt. It possesses a complex geological structure and hosts rocks of mantle, accretionary and post-orogenic associations. The volcanic and sedimentary rocks of the accretionary association belong to three suites: Itmurundy (O1-2), Kazyk (O2-3) and Tyuretai (O3-S1). The suites are separated by tectonic unconformities

AbstractThe article presents new geological, geochronological, mineralogical, geochemical, and isotopic data on the Early Cretaceous granitic rocks of the southern part of the Zhuravlevka Terrane (Sikhote-Alin). It is shown that four intrusive complexes containing significant amounts of granitic rocks were formed almost simultaneously in this area in the Early Cretaceous (about 100 Ma). These magmatic

AbstractThe results of prior studies are generalized and the author’s data on the geology, geochemistry, and isotope geochronology of the Early–Middle Devonian volcanic series of Western Gorny Altai and Rudny Altai that are related to two large volcanic systems, the Altai–Minusinsk and Altai–Salair, respectively, are presented. The studied basalts have convergent geochemical characteristics between

The results of the study of natural gas in Peter the Great Bay from 2009 to 2014 are reported. The data on the distribution of natural gas in the water and bottom sediments are obtained. High concentrations of gas in the bottom water and sediments are registered in some areas of the bay. The probable sources of methane and other natural gases are suggested.

Changes in mineralogical composition occurring in the course of preparation of drinking water in-situ are studied based on the data from the monitoring wells of the Tunguska groundwater intake. Intensive dissolution of feldspars, pyroxenes, siderite, and, to a lesser extent, quartz with the formation of secondary minerals (amorphous silica, clay minerals, and secondary siderite) occur in the aquifer

AbstractNew evidence of Eocene ingression in the area of the present-day Russian–Chinese border is provided. It was previously believed that Cenozoic grabens of the Tangcheng–Lujiang (Tan-Lu) Fault Zone, located in China and also traced in Russia, were filled predominantly by continental, rarely, lagoonal sediments. In 2015, drilling in the Huadian Basin (graben), which is part of the Tan-Lu system

The paper presents the results of geochemical and Sm–Nd isotope study of the metavolcanic rocks of the western part of the Tukuringra Terrane, one of the largest terranes of the Mongol–Okhotsk fold belt. It is shown that among the metavolcanics of the Teplokluchevskaya, Garmakan, and Algaja formations there are varieties similar to OIB and N-MORB, yet no rocks revealing features characteristic of the

This paper describes the conodont species found for the first time in Abrek Bay in the upper part of the Lower Triassic deposits, which are provisionally assigned through ammonoids to the Anasibirites nevolini zone. The study of the conodonts from these layers has made it possible to identify the assemblage composed of the species Concervatella concervativa (Müller), Ellisonia triassica Müller, Foliella

The by-products of the Far East Sn deposits related to Li–F granites include trace elements. The petrography and mineral composition of the Sn-bearing metasomatites of the Verkhneurmiysky ore cluster (VUOC) of the Amur region (feldspatites, greisens, zwitters, turmalinites, and chloritites) and the multistage complex rare-metal (RM) mineralization of the Sn occurrences in area of Li–F granites are