Òîì 32, 2, 2013 |
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A.P. Sorokin, Yu.F. Malyshev, V.B. Kaplun, A.T Sorokina, T.V. Artemenko. Main features of the evolution and deep structure of the Zeya-Bureya and Songliao sedimentary basins 3 V.M. Grannik, A.V. Litvinova, E.S. Rudnitskaya, A.Kh. Kim. Cenozoic sedimentary basins of the Okhotsk Sea region: peculiarities of their structure and formation 20 V.I. Isaev. Interpretation of highly accurate gravitation prospecting information by using mathematical programming 29 P.L. Nevolin, V.P. Utkin, A.N. Mitrokhin, S.A. Kasatkin. Role of the latitudinal compression in structural formation of the Paleozoic intrusions of South Primorye (Far East) 44 T.A. Emelyanova, E.P. Lelikov. Volcanism as an indicator of deep mechanism of the Japan and Okhotsk seas formation 63 S.M. Saprygin. Faults and seismicity of Sakhalin 73 V.G. Prokudin. Some aspects of the time cross-section interpretation from the reflection seismic data in the Okhotsk Sea 78 A.I. Obzhirov. Gas component increase during seismo-tectonics and the role of gas in earthquake origination (Okhotsk Sea) 86 L.B. Khershberg, E.V. Mikhailik, V.S. Pushkar, B.I. Vachaev. Structure, material composition of the Ilistaya series, the South Primorye shelf, and its potential exploration 90 V.I. Gvozdev, D.G. Fedoseev. Skarns of the Kordon tungsten deposit (Primorsky Territory) 100 I.G. Borisova. The role of landscape-geochemical researches in the system of mountain and ecological monitoring (exemplified from the Berezitovy mineral deposit, Amur Region) 112 A.P. Sorokin, Yu.F. Malyshev, V.B. Kaplun, A.T Sorokina, T.V. Artemenko Main features of the evolution and deep structure of the Zeya-Bureya and Songliao sedimentary basins (East Asia) The features of the evolution and deep structure of the Songliao and Zeya-Bureya basins are examined. The basin formation covered three stages including the riftogenic, platform and neotectonic ones. During the first stage (Middle Jurassic – Early Cretaceous), a uniform near-meridional riftogenic system was formed, whereas at the second stage (Late Cretaceous), oil source deep lacustrine sediments enriched in organic remains originated, whose maximum thickness attaining to 1100 m was determined for the Songliao basin. At the neotectonic stage, significant distinctions occurred in the basin development associated with the formation of transverse-latitudinal structures. The latter separated the basins and changed the hydrological regime resulting in cessation of the surface water discharge from the Zeya-Bureya basin to the Songliao basin. The differences in the deep structure of the basins are also strongly pronounced. High heat flow values more than 70 mW/m2 are typical of the Songliao basin, and its mantle heat flow component is higher than the crustal one, as compared to the Zeya-Bureya basin (below 50 mW/m2). In comparison with the Songliao basin, the crustal thickness in the Zeya-Bureya basin varies from 38 to 42 km and 29–34 km, accordingly, while the lithosphere thickness reaches 110–140 km and 50–75 km, respectively. The southern part of the Zeya-Bureya basin, which is close to the Songliao basin by its electrical resistivity values, is the only exception. The above indications are rather significant for estimating prospects for oil and gas content in the riftogenic zones. It has been established that in order to evaluate the prospects for oil and gas content of the sedimentary basins or their segments it is necessary to take into account the following two factors: 1) the influence of the lithospheric plates and the associated collision processes, and 2) anomalies of the deep structure of the lithosphere (high heat flow values, reduced thickness of the crust and the lithosphere). In this connection, the oil and gas content of the structures located mainly in the southern areas of the Zeya-Bureya basin, particularly, the Lermontovka, Dmitrievka, Mikhailovka, Ekaterinoslavka and Arkhara troughs, have been estimated by the authors as promising. Key words: Zeya-Bureya Basin, Songliao Basin, riftogenic, platform and neotectonic stages, crust, lithosphere, heat flow, conductivity, oil and gas content. V.M. Grannik, A.V. Litvinova, E.S.Rudnitskaya, A.Kh.Kim Cenozoic sedimentary basins of the Okhotsk Sea region: peculiarities of their structure and formation The peculiarities of the structure and formation of the Cenozoic sedimentary basins of the Okhotsk Sea region are exemplified from the North Sakhalin, Deryugin, Pogranichny, Yuzhno-Sakhalinsk, and West Kamchatka sedimentary basins. It was established that the formation of the basins and dislocations of deposits were connected with the development of the North Okhotsk, Tan-Lu-Okhotsk, Hokkaido-Sakhalin, and Okhotsk Sea–West Kamchatka pull-apart systems. Rift genesis repeatedly occurred under the influence of the deep-sea processes and large-scale interaction of lithospheric plates. Asthenospheric diapirs that controlled the rift genesis, magmatism, and thermal regime are considered the main reason of riftogenesis. Key words: sedimentary basin, seismic complex, seismic horizon, regional stratigraphical horizon, suite, rock, fold, fault, riftogenesis, dislocations, the Okhotsk Sea region. V.I. Isaev Interpretation of highly accurate gravitation prospecting information by using mathematical programming Non-linear (exponential) regularities of rock density changes with depth of coeval sedimentary complexes are proposed. A series of task solutions of direct and inverse problems of detailed and high-accuracy gravitation prospecting has been fulfilled which are typical for petroleum geology with or no consideration for the density gradient. It was concluded that there do not appear to be sufficient reasons for an increase in accuracy of gravimetric survey more than ±0.20 if the possibilities to create and record petrodensity relations (Z) are absent. Oil-and-gas-bearing complexes of the local objects were characterized in terms of lateral variability of their lithophysical features. Algorithms of mathematical programming and methods of 3D geodensity modeling of objects investigated by seismic prospecting were suggested. Inverse linear problems of high-accuracy gravitation prospecting were solved on the universal in complexity quasi-real model that enabled the authors to evaluate the possibilities of detection and delineation of unconsolidated (highly porous) lithofacies. Within the framework of the accepted model 3D task of high-accuracy gravitation prospecting was solved on the Verkhnenysh gas condensate deposit on Sakhalin. Key words: gravitation prospecting, oil-and-gas-bearing complex, 3D modeling, mathematical programming, Sakhalin Island. P.L. Nevolin, V.P. Utkin, A.N. Mitrokhin, S.A. Kasatkin Role of the latitudinal compression in structural formation of the Paleozoic intrusions of South Primorye (Far East) Specific features of the geologic location and structure of the Anna, Gaidamak, Dunay, Tinkan, and Tafuinsky gabbroid and granitic intrusions have been analyzed from structural and geodynamic positions. At present these intrusions are regarded as elements of the basite Sergeevka terrane formerly known as the Sergeevka metagabbroid uplift (or massif), while their outcrops taken together trace the Tafuin anticlinorium of ENE-trending formed in Mesozoic time as a part of a long-living Sergeevka structure in conjugation and synchroneity with the Petrovêà depression which joins it from the north. Hence it follows that the intrusions together with the Cretaceous massifs occurring among the Petrovka depression’s Mesozoic sediments are suggested as a result of the tectono-magmatic impulses which transformed the basite substratum. And the impulses are distributed within the Proterozoic-to Early Paleozoic, Late Paleozoic, and Mesozoic geodynamic periods, each of which is characterized by its lateral compression direction. The most intense was Late Paleozoic sublatitudinal lateral compression. Owing to this, the developing intrusions have acquired near-meridional oblongness in their morphology and the near-meridional dominant in the structural elements, namely: layering, striation, taxitic structure, cleavage foliation. This was predetermined by cleaving and thrusting (in the form of counter-dipping thrusts) of the same direction. At the same time shear-type pseudo-folds are manifested being regarded as derivatives of squeezing and crumpling. Key words: structural pattern, geodynamic periods, anisostatic stress field, axial compression, streakiness, layering, cleavage, pseudo-fold structures, intrusive massifs, South Primorye. T.A. Emelyanova, E.P. Lelikov
Volcanism as an indicator of deep mechanism of the Japan and Okhotsk seas formation The results of geochemical research of the Late Oligocene-Early Miocene volcanic rocks following the formation of the deep-sea basins of the Japan and Okhotsk seas are presented. These rocks have primary mantle genesis and they are the production of a single mantle source – spinel peridotite. These rocks developed as a result of partial melting of the protuberances (secondary plumes) located on the leading part of the main mantle plume. This plume rose near to the continental crust in the area of the Japan (Central) Basin where marginal marine basaltoids bearing HIMU (IOB) chemical features have been established. and the oceanic crust had being disclosed in the Japan Basin. At the earlier riftogenic stages (Late Oligocene-Early Miocene) and at the final stage (Pliocene-Pleistocene) continental lithosphere (upper mantle and crust) had taken part in magma genesis in the areas of the Kuril Basin and Vityaz Ridge. Key words: marginal seas, deep-water basins, volcanism,geochemistry, mantle sources, mantle plumes, Pacific Plate, Japan Sea, Okhotsk Sea. S.M. Saprygin
Faults and seismicity of Sakhalin Main faults of Sakhalin which differ in their behavior in the regional field of stresses are discussed for the first time. Locked, free, fault waveguides, and water-bearing faults have been distinguished. Such a description of faults stresses the difference of their seismic hazard and appears to be more suitable for seismic zoning. Key words: faults of Sakhalin; regional field of stresses; locked, free, fault waveguides and water-bearing faults; seismic zoning. V.G. Prokudin Some aspects of the time cross-section interpretation from the reflection seismic data in the Okhotsk Sea The study of the reflection seismic profiles in the Okhotsk Sea has revealed the presence of acoustic anomalies of two types – local (“gas chimney”) and areal (“turbid” substance). It was shown that acoustic anomalies on the continous seismic profiles are a good indicator of gas-bearing sediments with a partial gas filling. Numerous local anomalies recorded on the continental slope of Sakhalin are spatially related to zones of disjunctive dislocations. Simultaneous presence of both acoustic anomalies and bottom simulating reflector (BSR) in the upper part of the cross-section is a good diagnostic marker of gas hydrates. The seismic wavelet velocity dispersion is due to the acoustic anomaly generated in the lower part of the Kuril basin sediments. The velocity dispersion indicates the presence of thick gas-bearing sedimentary deposits of the structure. Key words: reflection method, time cross-section, acoustic anomaly, gas hydrates. A.I. Obzhirov Gas component increase during seismo-tectonics and the role of gas in earthquake origination (Okhotsk Sea) Since 1984 Laboratory of Gas Geochemistry POI FEB RAS has studied fluxes of methane bubbles from bottom sediments to water and partially from water to atmosphere in the eastern Sakhalin shelf and in the slope of the Okhotsk Sea. These investigations were thereafter carried out in many international expeditions. More than 500 bubbles of methane fluxes have been found and 15 gas hydrate areas associated with them have been discovered in the upper beds of the bottom sediments. From 1988 to 2011 the methane fluxes increased in abundance, and the concentration of methane in water and bottom sediments increased 1000–10000 times relative to the background. It is due to seismo-tectonic activation of the western Pacific region which resulted in the increase of a number of faults. Along the faults gas fluid flows migrated to the surface from the depths. On the one hand, the gas facilitates generation of gas hydrates in the upper beds of the bottom sediments and on the other gas expands fissures causing a sharp sliding of the crust blocks and providing origination of earthquakes and in some cases tsunami waves. It is confirmed by a series of the following earthquakes in the region: Neftegorsk (1995), Uglegorsk (2001), Hokkaido (2003), Nevelsk (2007), and Fukusima (2011). Key words: flux of methane, gas hydrates, faults, seismo-tectonic activity, earthquakes, Okhotsk Sea. L.B. Khershberg, E.V. Mikhailik, V.S. Pushkar, B.I. Vachaev Structure, material composition of the Ilistaya series, the South Primorye shelf, and its potential exploration The Ilistaya series has been initially revealed in the stratigraphic section of Quaternary shelf deposits during the geological survey on a scale of 1:200 000 and geological exploration carried out by the Pacific Marine Expedition (PTGA). It was found in some gulfs and bays along the South Primorye shelf (the Sea of Japan). The sections of the Ilistaya Series have been studied, and the composition, volume and quality of multicomponent raw materials (seashells and black mud) have been estimated. Explored reserves of these deposits can supply the Far Eastern region fowl-farms with nutritive additives. Key words: Ilistaya series, stratigraphy, reserves of multicomponent raw materials, Sea of Japan. V.I. Gvozdev, D.G. Fedoseev Skarns of the Kordon tungsten deposit (Primorsky Territory) Skarns of the Kordon tungsten deposit located in the Malinovy ore joint, Primorsky Territoryá were examined from cores of the boreholes. Mineral types of the skarns and near-skarn rocks have been defined, and a brief description and ore specialization are given. Typomorphic peculiarities of rock-forming skarns are correlated with reference objects of the region. The problems of skarn genesis are discussed. Key words: skarns, mineralogy, tungsten deposits, genesis, Primorsky Territory. I.G. Borisova The role of landscape-geochemical researches in the system of mountain and ecological monitoring (exemplified from the Berezitovy mineral deposit, Amur Region The importance of landscape-geochemical information for mountain and ecological monitoring is exemplified from the Berezitovy deposit, the Amur Region. Material composition of geosystems was investigated in the deposit territory. The migration processes in the rock – water – soil – plant system are characterized, which allow systematizing landscape-geochemical information and using it in the context of mountain and ecological monitoring. Key words: mountain and ecological monitoring, elementary geochemical landscape, geosystem, landscape and geochemical evidence, migration of chemical elements, migration coefficients, biogenic migration, water migration, Amur Region. |