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The Main Types of Paleogene Sedimentary Rocks and Conditions of their Formation on the Guyots of the Magellan Seamounts (Pacific Ocean) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2021-02-25 S. P. Pletnev
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
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The First U–Pb SHRIMP Dating of Zircons from Capitanian (Middle Permian) Deposits of the Omolon Massif (Northeast Russia) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2021-02-25 I. V. Brynko, G. O. Polzunenkov, A. S. Biakov, I. L. Vedernikov
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
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The First Evidence for Late Devonian Granitoid Magmatism in the Northeastern Flank of the South Mongolia–Khingan Orogenic Belt Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2021-02-25 Y. V. Smirnov, A. A. Sorokin, N. M. Kudryashov
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
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Lower Silurian Terrigenous Rocks of the Laoeling–Grodekovo Terrane, Southern Primorye: Composition and Formation Settings Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2021-02-25 A. I. Malinovsky, V. V. Golozubov
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
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The Mineral Composition of Sediments as an Indicator of the Supply Sources and Features of the Distribution of Clastic Material in the Sea of Okhotsk Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2021-02-25 N. A. Nikolaeva, A. N. Derkachev, I. V. Utkin
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
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The Iorokhan Complex of Minor Intrusions in the Eastern Part of the Bureya Massif: Geology, Age, and Gold Mineralization Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2021-02-25 E. V. Nigai, V. A. Guryanov, S. N. Dobkin, M. V. Arkhipov
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
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Integrated Geological–Geophysical, Gas-Geochemical and Oceanographic Research in the Sea of Japan and the Tatar Strait during the 85th Cruise of the R/V Akademik M. A. Lavrentyev Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-12-10 M. G. Valitov, N. S. Lee, A. V. Yatsuk, Z. N. Proshkina, A. L. Ponomareva, V. V. Kalinchuk, S. P. Pletnev, E. N. Marina, A. I. Obzhirov, R. B. Shakirov, D. A. Shvalov, M. A. Bovsun
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
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The Crust and Upper Mantle Structure of the Southern Sikhote Alin from Magnetotelluric Sounding and Density Modeling Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-12-10 V. B. Kaplun, M. Yu. Nosyrev
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
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Methane Flows and Gas Hydrates in the Transition Zone Between the Western Slope of the Kuril Basin and Offshore from Sakhalin Island Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-12-10 A. I. Obzhirov, Yu. A. Telegin, R. B. Shakirov, A. S. Salomatin, A. N. Derkachev, N. S. Syrbu, N. S. Li, A. L. Ponomareva, A. I. Es’kova
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
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The Ore and Petroleum Regions of the South Okhotsk Province and Deep Geodynamics Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-12-10 V. G. Khomich, N. G. Boriskina
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
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The Role of the Pyroxenite Mantle in the Magma Genesis of the Oligocene Basalts from the Northern Part of East Sikhote Alin Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-12-10 A. Yu. Martynov, Yu. A. Martynov, A. I. Malinovskii
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
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The Fractal Geometry of the River Network and Neotectonics of South Sikhote-Alin Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-12-10 V. S. Zakharov, D. A. Simonov, G. Z. Gilmanova, A. N. Didenko
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
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A Seismostratigraphic Model of the Aldan–Maya Sedimentary Basin of the Southeastern Siberian Platform Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-12-10 E. P. Razvozzhaeva
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
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The Geochemistry of the Mineral Waters and Hydrogenic Sediments of the Antonovsky Hydrosulfuric Mineral Spring, Sakhalin Island Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-12-10 G. A. Chelnokov, I. V. Bragin, N. A. Kharitonova, K. Yu. Bushkareva, V. Yu. Lavrushin, R. V. Zharkov, B. I. Chelnokova, A. A. Karabtsov
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
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The Geochemical Features of Ores and Host Rocks of the Malo-Taryn Orogenic Gold Deposit (Verkhoyansk–Kolyma Folded Area, Northeast Russia) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-10-08 L. I. Polufuntikova, V. Y. Fridovsky, N. A. Goryachev
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
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The Middle Paleocene–Early Eocene (60.5–53.0 Ma) Magmatic Stage in the Southern Russian Far East Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-10-08 A. V. Grebennikov, S. A. Kasatkin, D. G. Fedoseev, A. I. Khanchuk
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
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The Features of the Deep Velocity Structure of the Trans-Baikal Section of the Central Asian Fold Belt from the Seismological and DSS Data (Alignment of the 1-SB Reference Profile) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-10-08 V. M. Solovyev, A. S. Salnikov, V. S. Seleznev, V. V. Chechelnitsky, A. V. Liseikin, N. A. Galeva
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
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The Origin and Mechanism of Formation of Hydrocarbon Deposits of the Vietnamese Shelf Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-10-08 M. G. Leonov, V. Yu. Kerimov, R. N. Mustaev, Vu Nam Hai
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
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Rational Use of the Elemental Potential of the Pavlovsk Deposit Coal (Primorye) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-10-08 A. V. Podgaetskii
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
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Volcanic Rocks in the Udyl’ Segment of the Kiselevka–Manoma Accretionary Terrane (Sikhote-Alin): Petrogeochemistry, Formation Conditions, and Tectonic Setting Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-10-08 I. P. Voinova, A. N. Didenko, A. V. Kudymov, A. Yu. Peskov, M. V. Arkhipov
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
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The Specific Features of the Geodynamic Settings in the Southeastern Part of the Magellan Seamounts, Pacific Ocean Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-10-08 S. I. Petukhov, V. M. Anokhin, M. E. Melnikov, T. E Sedysheva
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
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New Findings and Stratigraphic Distribution of Foraminifera from Permian–Triassic Boundary Deposits in the Southern Verkhoyansk Region Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-10-08 A. V. Yadrenkin, A. S. Biakov, R. V. Kutygin, A. V. Kopylova
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
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Particle-Size Analysis of Modern Bottom Sediments by the Laser Diffraction and Sieve Methods Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-08-07 V. M. Shulkin; A. Yu. Strukov
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
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The Crust and Upper Mantle Structure of the Southern Sikhote Alin from Magnetotelluric Sounding Data along the Abrazheevka–Valentin Profile Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-08-07 V. B. Kaplun; A. K. Bronnikov
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
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The Geology and Thermochronology of Cretaceous Magmatism of Southeastern Vietnam Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-08-07 A. G. Vladimirov; L. A. Phan; A. V. Travin; E. I. Mikheev; N. G. Murzintsev; I. Yu. Annikova
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
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Earthquake Migration and Hidden Faults in the Priamurye Region Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-08-07 V. G. Bykov; T. V. Merkulova
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
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Minerals in Manganese Deposits of Belyaevsky Volcano, the Sea of Japan Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-08-07 Yu. G. Volokhin; P. E. Mikhailik; E. V. Mikhailik
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
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Gold–Palladium–Platinum Mineralization of Paleocene Explosive Structures, the Taukha Terrane, Sikhote-Alin Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-08-07 E. V. Perevoznikova; V. T. Kazachenko
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
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Granitoids of the Khara Complex in the Eastern Bureya Continental Massif of the Central Asian Orogenic Belt: Age and Geodynamic Settings of Formation Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-07-01 V. A. Guryanov; S. A. Amelin; Yu. Yu. Yurchenko; E. V. Nigai; V. N. Arapov; M. V. Arkhipov
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
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Redox conditions and related geochemical and metallogenic zonation of magmatic rocks of the Sikhote Alin Orogenic Belt Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-07-01 L. F. Mishin; E. A. Konovalova; Yu. V. Taltykin; V. O. Krutikova; S. N. Dobkin; Yu. Yu. Yurchenko; A. V. Shtareva
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
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On the Possibility of Age Correlation of the Geological Complexes in the area of the Kuril Island Arc System from Seismoacoustic Parameters Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-07-01 E. P. Terekhov; T. A. Kharchenko
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
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Dike Complexes of the Gromadnen–Vurguveem Ophiolite Massif, West Chukotka: Composition and Geodynamic Setting Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-07-01 A. V. Ganelin; S. D. Sokolov
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
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Ages and Sources of Sedimentary Rocks of the Lan Terrane in the Mongol-Okhotsk Fold Belt: Results of Zircon U-Pb and Lu-Hf Isotope Studies Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-07-01 V. A. Zaika; A. A. Sorokin
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
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Island-Arc Ophiolites of the Hahajima Seamount (Bonin Trench, Philippine Sea) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-07-01 A. N. Golich; S. V. Vysotskiy
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
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The Earth’s Crust Density Inhomogeneities and Stresses in the Central Kuriles Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-04-08 R. G. Kulinich; E. B. Osipova; M. G. Valitov
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
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Reconstruction of Late Holocene Extreme Hydrological Events of the Valentin Bay Coast, the Sea of Japan Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-04-08 N. G. Razjigaeva; L. A. Ganzey; Yu. Nishimura; T. A. Grebennikova; D. Sugawara; Y. Takashimizu; I. I. Lebedev; A. O. Gorbunov; Kh. A. Arslanov; F. E. Maksimov; A. Yu. Petrov
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
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Gas Flows in the Sea of Okhotsk Resulting from Cretaceous-Cenozoic Tectonomagmatic Activity Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-04-08 A. I. Obzhirov; T. A. Emelyanova; Yu. A. Telegin; R. B. Shakirov
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
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Geochemistry and Magnetism of Peat Deposits in the Khor–Kiya Interfluve, Sikhote–Alin (Preliminary Results) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-04-08 A. Yu. Peskov; V. O. Krutikova; E. N. Zakharchenko; V. V. Chakov; M. A. Klimin; A. S. Karetnikov; A. N. Didenko
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
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New Data on the Crust and Upper Mantle Structure of the Southeast China Obtained from Statistical Processing Results of Gravity Anomalies Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-04-08 A. M. Petrishchevsky
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
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Triassic Stage in the Evolution of Mesozoic Sedimentogenesis of the Mongol–Okhotsk Fold Belt Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-04-08 G. L. Kirillova
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
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Petrology of Nickeliferous Mafic–Ultramafic Bodies of the Southeastern Aldan-Stanovoy Shield Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-04-08 V. S. Prikhodko; L. L. Petukhova; V. A. Guryanov; V. M. Chubarov
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
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Isotopic Age of Native Platinum from Andesitic Fluidolites of the Poperechnoye Deposit (Malyi Khingan, Russia) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-03-16 A. I. Khanchuk; A. G. Mochalov; I. Yu. Rasskazov; O. V. Yakubovich; N. V. Berdnikov; V. G. Nevstruyev
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.
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Petrography and Geochemistry of Cenozoic Sandstones in the Dunhua Basin, Northeast China: Implications for Provenance, Source Weathering, and Tectonic Setting Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-03-16 Fei Hu; Zhaojun Liu; Qingtao Meng; Jinjun Xu
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
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Tectonic Implications: Zircon age of Sedimentary Rocks from Khabarovsk, Samarka, and Zhuravlevka-Amur Terranes in the Northern Sikhote-Alin Orogenic Belt Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-03-16 A. N. Didenko; Sh. Otoh; A. V. Kudymov; A. Yu. Peskov; M. V. Arkhipov; Yu. Miyake; M. Nagata
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
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Geochemistry and Genesis of Hydrocarbon Gases of the Chaun Depression and Ayon Sedimentary Basin of the East Siberian Sea Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-03-16 A. I. Gresov; A. V. Yatsuk
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
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Mineral Evolution during Formation of Gold–Rare-Metal Ores in the Sredne-Golgotay Deposit (Eastern Transbaikalia) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-03-16 V. I. Gvozdev; A. A. Grebennikova; A. S. Vakh; N. A. Goryachev; D. G. Fedoseev
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
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The Age of the Kubaka Epithermal Gold-Silver Deposit (Omolon Massif, Northeast Russia): Geological and Isotopic-Geochronological Constrains (U-Pb and 40 Ar/ 39 Ar Methods) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-03-16 V. V. Akinin; A. N. Glukhov; G. O. Polzunenkov; A. V. Alshevsky; D. I. Alexeev
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)
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Age and Sources of Dzhagdy Terrane Metasedimentary Rocks in the Mongol–Okhotsk Fold Belt: Detrital Zircon U–Pb and Lu–Hf Isotopic Data Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-03-16 V. A. Zaika; A. A. Sorokin
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
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A New Ammonoid Zone of the Upper Carnian Substage in Northeastern Russia Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-02-18 A. G. Konstantinov
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
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Accretion of the Anuy Zone, Tectonic Zonation, and Evolution of the Samarka Accretionary Complex: Details of Evolutionary Scenario of the Sikhote-Alin Segment of the East Asian Continental Margin Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-02-18 S. V. Zyabrev; E. K. Shevelev
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
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Rare-Earth Elements and Noble Metals in Phosphorites of the Gremuchy Occurrence, Lesser Khingan, Far East of Russia Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-02-18 A. A. Cherepanov; N. V. Berdnikov; A. V. Shtareva
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)
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Paleomagnetism and Petrochemistry of Sandstones from the Gorinskaya and Pionerskaya Formations, Zhuravlevka–Amurian Terrane (Northern Sikhote Alin) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-02-18 A. Yu. Peskov; A. N. Didenko; A. V. Kudymov; A. S. Karetnikov; M. V. Arkhipov
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
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Structure of the Lithosphere in the Zone of the Continent–Ocean Transition in the Southern Part of the Russian Far East: Evidence from the Density Modeling Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-02-18 E. G. Ivolga; Yu. F. Manilov
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
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The Rotational Tectonics of the Agnie–Afanas’evskii Ore Cluster in the Lower Amur Region Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-02-18 Yu. P. Yushmanov
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
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40 Ar/ 39 Ar Age of Gold Ore Metasomatites of the Albyn Deposit, Mongol–Okhotsk Fold Belt Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-02-18 A. Yu. Kadashnikova; A. A. Sorokin; A. V. Ponomarchuk; A. V. Travin; V. A. Ponomarchuk; A. I. Dementienko; L. V. Eirish
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
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Tectonic Fracturing of the Lithosphere of the Priamurye Region by Submeridional and Sublatitudinal Faults (from Geophysical Data and Relief Analysis) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2020-02-18 T. V. Merkulova; G. Z. Gil’manova; S. A. Tusikova
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
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Orogenic Gold Mineralization of the Adycha Ore Region (East Yakutia, Russia): Geological Setting and Geochemical Features of Gold–Quartz Ores Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2019-10-03 V. V. Aristov; O. B. Ryzhov; A. A. Volfson; N. V. Sidorova; A. V. Kurmayev
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
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The Crust and Upper Mantle Structure of the Southern Sikhote Alin along the Profile Dal’nerechensk–Roshchino–Plastun from Magnetotelluric Sounding Data Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2019-10-03 V. B. Kaplun; A. K. Bronnikov
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
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Physicochemical Conditions of Quartz Formation at the Bazov Gold-Ore Deposit (East Yakutia, Russia) Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2019-10-03 V. Y. Fridovsky; S. G. Kryazhev; N. A. Goryachev
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
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Clay Minerals in Sediments from the Central Part of the Guaymas Basin, the Gulf of California, Hole 478 Russ. J. of Pac. Geol. (IF 0.375) Pub Date : 2019-10-03 V. B. Kurnosov; B. A. Sakharov; A. R. Geptner; Yu. I. Konovalov; E. O. Goncharov
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
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