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Òîì 33, 2, 2014 |
| V.G. Nevstruev, N.V. Berdnikov, V.P. Nechaev.
Geochemical characteristics of PGE-bearing
carbonaceous units from the Eastern Bureya
Massif 3 S.V. Tochilina, L.N. Vasilenko. New data on the stratigraphy of the Japan Trench island slope 15 Min Gao, Jiu Chuanwei , Ping Liwang. Correlation of Cambrian chronostratigraphic division in Shandong 13 Kononets S. N., S’edin V. T., Kharchenko T. A., Valitov M. G., Izosov L. A. Types and physical properties of igneous rocks of the Popov Island (Peter the Great Bay, Sea of Japan) 39 A.V. Aseeva, S.V. Vysotskiy, A.A. Karabtsov, I.A. Alexandrov, I.S. Chyvashova. Transformation of garnet megacrysts captured by alkali mafic magma 53 A.Yu. Polets, T.K. Zlobin. Estimation of the stress state of the earth’s crust and the upper mantle in the area of the Southern Kuril Islands 64 A.F. Makhinova, A.N. Makhinov, V.A. Kuptsova, Liu Shuguang, V.V. Ermoshin. Landscape-geochemical zoning of the Amur River basin (Russian Territory) 76 A.G. Boldeskul, V.V. Shamov, B.I. Gartsman, N.K. Kozhevnikova. Main ions in water of different genetic types in a small river basin: case experimental studies in Central Sikhote-Alin 90 E.A. Elbakidze. The extent of the Japan Sea Holocene ingression in Southern Primorye from the diatom analysis data 102 V.V. Sattarova, N.V. Zarubin, M.G. Blokhin, A.A. Maryash. Rare-earth elements in the surface sediments from the Deryugin basin (Okhotsk Sea) 109 V.G. Nevstruev, N.V. Berdnikov, V.P. Nechaev Geochemical characteristics of PGE-bearing carbonaceous units from the Eastern Bureya Massif Geochemical characteristics of Au- and PGE-bearing carbonaceous shales from the Sutyr and Kimkan units, the eastern Bureya massif (Russian Far East) are discussed. Major-element composition of the shales are similar to common shales of the upper Earth’s crust (NASC) differing from them by lower concentrations of Fe, Mn, Mg, P, Ca, and REE. They show similarity with modern sediments deposited under influence of continental and volcanic arc debris, as well as supersubduction volcanism and marine waters in combination indicating either a deep sea trench adjacent to an active continental margin or a central marginal sea. The iron-rich sedimentary rocks of the Kimkan unit including the Kimkan ores are characterized by a positive Eu anomaly evidently reflecting their accumulation in a rift basin. Superimposed hydrothermal alteration of the Sutyr rocks including sericitization, sulfide impregnation and quartz veinlets were accompanied by outflow of silica and inflow of potassium, light and middle REE forming a distinct negative Eu anomaly. The Kimkan deposits show depletion of alkaline elements more sufficient for K in the metalliferous sediments comparative to common shales. Carbon isotopic composition of the Sutyr shales corresponds to that of the organic matter ( δ13CVPDB from -20.7 to -23.7 ‰). The Kimkan shales are characterized by a heavier isotopic composition (δ13CVPDB from -15.6 to -19.1 ‰) evidencing that its carbon is either partly derived from a deep source or resulted from decarbonatization in the presence of iron. Key words: geochemical characteristics, precious metal mineralization, gold, platinoids, carbonaceous shales, Au, platinoids, Sutyr and Kimkan units, Bureja Massif. S.V. Tochilina, L.N. Vasilenko New data on the stratigraphy of the Japan Trench island slope Results of the ecostratigraphic analysis using statistical data handling of radiolarian fauna from the sections of sites 434, 434A, 434B firstly allow us: (1) to identify the stratigraphic succession and some hiatuses in the hemipelagic sedimentation, and (2) to determine the age of basal layers of the sedimentary cover as an Oligocene-early Miocene boundary. The results obtained present new data on the age and environmental conditions of the formation of the sedimentary cover of the Japan Trench island slope. The "layers with radiolarians" correspond to previously determined zones. The boundaries of "layers with radiolarians" are marked by radiometric dates obtained on sections of the Japan Sea on transect: sites 436, 439 and 584. It enabled to reveal the cyclicity of the sedimentation process. Key words: Radiolaria, Miocene, Pliocene, Pleistocene, Japan Trench. Min Gao, Jiu Chuanwei , Ping Liwang Correlation of Cambrian chronostratigraphic subdivision in Shandong The aim of the paper is to solve many confused problems of the Cambrian chronostratigraphic subdivision in Shandong and determine the bottom boundaries of the Cambrian local stages. By analyzing domestic and foreign researches on the Cambrian, the delimitations of Shandong Cambrian stages are contrasted with the globe and South China’s update Cambrian chronostratigraphic subdivisions based on the trilobite fossils. The main problems of the Cambrian chronostratigraphic subdivision in Shandong are discussed by the biostratigraphic methods. Finally, the research shows that the subdivisions of the Canglangpuian, Longwangmiaoan, Maozhuangian, Hsuchuangian, and Fengshanian stages in Shandong cannot be correlated with the subdivisions of the International Stratigraphic Chart. The lower boundary of the Zhangxian stage in Shandong corresponds to that of the global Drumian stage, the bottom boundary of the Gushanian stage is in agreement with that of the Guzhangian stage within the globe, and the lower boundary of the Furongian series of the globe is slightly lower as compared with that of the Changshanian stage in Shandong. The layer of the Iapetognathus conodont first appeared at the Cambrian–Ordovician boundary. Key words: correlation, Cambrian, chronostratigraphic, subdivisions, trilobite, Shandong, the International Stratigraphic Chart, South China. S.N.
Kononets, V.T. S’edin, T.A. Kharchenko, M.G.
Valitov, L.A. Izosov
Types and physical properties of igneous rocks of the Popov Island (Peter the Great Bay, Sea of Japan) The paper presents the results of geological and petrophysical researches carried out on the Popov Island by the Pacific Oceanological Institute of Far Eastern Branch of Russian Academy of Science during 2003 - 2009. As a result, there were established 7 types of igneous rocks. Their density and magnetic susceptibility have been determined. It was established that the rock types are clearly differentiated with respect to their physical parameters. The identified relationship allows these physical properties to be used first of all for geological interpretation of gravity and hydromagnetic survey on the surrounding water area of the Peter the Great Bay and, secondly, as an additional indicator of igneous rocks typing on the other islands of the region. A similar complex of works in this area was carried out for the first time. The results obtained are essential for solving the problem of structural, substantial and genetic relationships of the terrestrial and marine structures at the junction zone between the Japan Sea Basin and adjacent continent. Key words: geological structure, igneous rocks, physical properties, density, magnetic susceptibility, Popov Island, Sea of Japan. A.V.
Aseeva, S.V. Vysotskiy, A.A. Karabtsov, I.A.
Alexandrov, I.S. Chuvashova
Transformation of garnet megacrysts captured by alkali mafic magma Results of research of symplectites from the Shavaryn-Tsaram (Hangaj plateau, Mongolia) and Bartoj (Dzhida basaltic field, Russia) alkali basaltic rocks are presented. The symplectite compositions and structures were studied, and physical and chemical parameters at which primary megacrysts were transformed into secondary mineral assemblages, were defined. It is established that both garnet megacrysts and garnet-pyroxene aggregates were formed at pressure of 10-13 kbar and temperature over 1300 ºC. Transformation of garnet into minerals of the secondary assemblage is considered as solid state water assisted resorption of garnet at a depth corresponding to pressure of 4-8 kbar and the temperature ranged from 1000 to 1300 ºC. Kelyphitic rims on the garnet megacrysts resulted from melting of the megacrysts on the contact with the hosting alkali basaltic rock. Key words: garnet, megacrysts, alkali basalts, symplectite, Transbaikalie, Mongolia. A.Yu. Polets, T.K. Zlobin Estimation of the stress state of the earth’s crust and the upper mantle in the area of the Southern Kuril Islands The catastrophic Shikotan earthquake 4(5).10.1994 occurred in the Pacific Ocean. Its focus was located 80 km east of the Shikotan Island. For estimation of the Earth’s crust stress state, the method of cataclastic analysis of the whole range of earthquake mechanisms was used. The fulfilled reconstruction of the parameters of the Earth’s crust stress state and upper mantle allowed the determination of the presence of extensive areas with a stable behavior of the stress tensor parameters typical for this area, and on the other hand, there were revealed some local areas with abnormally rapid changes in these parameters. Key words: The Southern Kuril Islands, Shikotan Island, earthquakes, the Earth’s crust, upper mantle, stress state. A.F. Makhinova, A.N. Makhinov, V.A. Kuptsova, Liu Shuguang, V.V. Ermoshin Landscape-geochemical zoning of the Amur River basin (Russian Territory) The landscape-geochemical characteristics of the Russian part of the Amur Basin under study are presented. The degree of correlation of geographic factors with mechanisms of the formation of soil geochemical systems is described. Spatial heterogeneity of concentrations of chemical elements in the background soils is viewed as a function of migration activity of elements of the iron group in the organo-mineral complexes. Importance of elements of the iron group is revealed in forming regional geochemical pattern. The conditions of substance migration are revealed. The formation of conjugated landscape-geochemical structures is briefly reviewed. New approaches and principles of landscape-geochemical zonation are proposed. The described aspects were applied to create the map “Landscape-Geochemical Zoning of the Amur Basin” (1:2 500 000). The map reflects landscape-geochemical structures, which determine conditions of substance migration and spatial heterogeneity of chemical element concentrations in the background soils. Key words: the Amur River basin, soils, soil geochemical fluxes, migration zone, landscape-geochemical zonation. A.G. Boldeskul, V.V. Shamov, B.I. Gartsman, N.K. Kozhevnikova Main ions in water of different genetic types in a small river basin: case experimental studies in Central Sikhote-Alin In this article, the results of detailed experimental investigation of main ions in waters within a small river basin are considered. The data were obtained on the base of comprehensive hydro-logical and geochemical monitoring of natural waters along semi-movable or expeditionary field studies during warm periods of 2011 and 2012. According to main ions, water samples were split onto seven genetic water classes as 1) cyclonic rain, 2) intermittent rain, 3) throughfall, 4) talus flow, 5) low-water streamflow (specific discharge is less 2.5 l/s•km2), 6) low flood streamflow (specific discharge is more 2.5 and less 16 l/s•km2), and 7) medium flood streamflow (specific discharge is more 16 and less 100 l/s•km2). Also, there were identified the four main groups of riverine dissolved macro-compounds that differ in terms of type of their dependence with flow rate. They are a) the compounds directly dependent with flow rate, b) the compounds inversely dependent with flow rate, c) the compounds independent evidently with flow rate, and d) the compounds that are charac-terized by complicated (fuzzy) dependence with flow rate. Keywords: natural water chemical composition, small river basin, Sikhote-Alin. E.A. Elbakidze The extent of the Japan Sea Holocene ingression in Southern Primorye from the diatom analysis data A complex rhythm system of paleoclimatic and related transgressive-regressive cycles of the Flandrean transgression in Holocene was determined from alteration of ecological structure of diatom communities from the sediments of the Razdol’naya River terrace, Souther Primorye, above the flood plain. The analysis of the subsequent replacements of the lagoon-marine diatom assemblages by lacustrine, alluvial and marsh ones leads one to establish the amplitudes of the Japan Sea fluctuations and degree to what ingression penetrated into the river valley. The maximum of the ingression penetration (up to 23 km from the sea-shore) along the river-valley corresponds to the Holocene climatic optimum when the sea level could be +3 m higher than the present one and influence the formation of the coast line. Key words: diatoms, the Japan Sea ingression, Holocene, Southern Primorye. V.V. Sattarova, N.V. Zarubin, M.G. Blokhin, A.A. Maryash Rare-earth elements in the surface sediments from the Deryugin basin (Okhotsk Sea) The content and distribution of the rare-earth elements (REE) in the surface sediments from the Deryugin Basin, Okhotsk Sea, was studied. The total REE content in the sediments makes 30.6-124.7 ppm. Minor predominance of the LREE over HREE and the presence of a small positive Eu anomaly (Eu/Eu* = 0.91-1.35) was established with the exception of the REE content for the samples located in the area of hydrothermal mountains. Its total REE content is significantly lower than in other samples and makes 9.6 ppm. The value of Eu/Eu* in this sample is 6.9. It is assumed that this anomaly may be related with the supply of gasohydrothermal fluids through the deep-seated fault. Key words: rare-earth elements, geochemistry of sediments, Deryugin Basin, Okhotsk Sea. |