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Òîì 33, 5, 2014 |
| P.E. Mikhailik, E.V. Mikhailik, N.V. Zarubina,
N.N. Barinov, V.T. S’edin, E.P. Lelikov.
Matter composition and REE distribution in ferromanganese
crusts of submarine Belyaev and Medvedev mounds from the Sea
of Japan 3 I.A. Tararin, Z.G. Badredinov, V.M. Chubarov. Geochemistry of metabasites of the Kolpakov Series as reflection of the sialic nature of the Sredinnyi crystalline massif basement of Kamchatka 17 O.S. Urman, O.S. Dzyuba, G.L. Kirillova, B.N. Shurygin. Buchia faunas and biostratigraphy of the Jurassic–Cretaceous boundary deposits in the Komsomolsk section (Russian Far East) 34 S.V. Rasskazov, T.A. Yasnygina, I.S. Chuvashova. Mantle sources of the Cenozoic volcanic rocks of East Asia: Derivatives of slabs, sublithospheric convection and lithosphere 47 V.V. Kulakov. Geological-structural and hydrothermal conditions for the formation of groundwater in Priamurye 66 V.V. Ratkin, V.I. Gvozdev, O.A. Karas’. Boron-polymetallic metallogeny of the northern and northeastern Sino-Korean craton 80 Kudymov À.V., P.A. Koltun, G.A. Zlobin. Structure forming processes in the north-eastern zone of the Kolumbinsky fault (the Northern Sikhote-Alin) 91 A.A. Golieva, L.A. Matyushkina, G.V. Kharitonova, V.S. Komarova. Phytoliths in meadow soils of the Middle Amur Lowland 101 P.E. Mikhailik, E.V. Mikhailik, N.V. Zarubina, N.N. Barinov, V.T. S’edin, E.P. Lelikov Matter composition and REE distribution in ferromanganese crusts of submarine Belyaev and Medvedev mounds from the Sea of Japan The paper presents the results of an integrated study of ferromanganese crusts of submarine Belyaev (Central sag) and Medvedev (Honshu sag) mounds from the Sea of Japan. The study of the mineral composition by powder diffractometry and optical and electron microscopy has evidenced that the samples are composed of todorokite, birnessite, and pyrolusite along with the minerals characteristic for hydrothermal ferromanganese deposits of the World Ocean. The composition of the ferromanganese crusts from the Sea of Japan was determined by ICP-MS and ICP-OES methods. The contents of Mn, Fe, Co, Cu, Ni and other trace and macroelements infer their hydrothermal origin. Geochemistry of rare earths and yttrium is paid a special attention because of their sensitive response to the changes of physical and chemical conditions of the environment, and thus their distribution in various rocks differs. The results obtained on the matter composition of the ferromanganese crusts form the Sea of Japan and their correlation with World Ocean deposits of different types indicate the endogenic origin of the studied crusts. However, data on REE and Y distribution testify to a significant mixture of hydrogenic matter participating in the growth of the ferromanganese crusts of submarine Belyaev and Medvedev volcanoes. Key words: ferromanganese crusts, mineralogy, geochemistry, REE, submarine volcanoes, Sea of Japan. I.A. Tararin, Z.G. Badredinov, V.M. Chubarov Geochemistry of metabasites of the Kolpakov Series as reflection of the sialic nature of the Sredinnyi crystalline massif basement of Kamchatka Metabasites (amphibolites, garnet amphibolites, and basic crystalline schists) compose numerous schists (often intensively boudinaged) from the first to 50-100 m thick in plagiogneisses and migmatites of the Kolpakov Series. Chemically, they are reconstructed as basalts and picrites undergone metamorphism isofacial with enclosing them apoterrigenous rocks under conditions of kyanite-sillimanite subfacies of amphibolite facies (t = 620º–650° C; Ps = 5.9–6.9 kbar). Metabasites are dominated by amphibolites and basic schists spread throughout the section of the Kolpakov Series, whereas the garnet amphibolites are more typical of the upper part of the series where they associate with amphibolites, basic schists, plagiogneisses, and quartzites. Metaultrabasites (plagioclase-free amphibolites) are found much more rarely as small boudins about first meters in size. According to U-Pb-SHRIMP dating of zircons the protolith age corresponds to the latest Early Cretaceous-Late Cretaceous (90–100 Ma) and is analogous to the that of the poorly metamorphosed terrigenous deposits of the Kikhchiksky Series of the Sredinnyi Massif that allows us to consider the terrigenous rocks of these series as isofacial sedimentary deposits. The same age (Early and Late Cretaceous boundary) is assumed for the protoliths of metabasites that occur as interbeds among the metaterrigenous deposits of the Kolpakov Series. The period of 90–100 Ma coincides with the beginning of the development of the Okhotsk-Chukotka volcanogenic marginal-continental belt in East Asia. It is shown that the Kolpakov Series metabasites possess the geochemical features of tholeiitic basalts of different geodynamic regimes and comprise both typically island-arc (low-titanium) and typically oceanic (moderate- and high-titanium) tholeiites associated with ultrabasic volcanites – picrites. Similar specificity of the basic rock chemistry characterizes the marginal-continental zones of extension (pull-apart basins) located on the crust of sialic type was caused by the interrelations between mantle melts and continental crust rocks. It is obvious that similar geodynamic conditions of basite magmatism existed for the Sredinnyi Range of Kamchatka. Ascent of the mantle matter beneath the extension zone of the sedimentary basin continental crust and crossing it by faults arisen simultaneously with the formation of the Okhotsk-Chukotka volcanogenic belt were the beginning of the basite volcanism manifestation in the sedimentary basin. They provided the intensive fluid effect and temperature increase in the crust with subsequent granitization and metamorphism of volcanogenic-terrigenous deposits and finally the development of the modern structure of the Sredinnyi crystalline massif. Intensive basite volcanism and initiated by it granitoid magmatism of the Late Cretaceous time in Kamchatka was, probably, caused by the ascent of mantle plumages bearing the hydrogen fluids. Key words: Kolpakov Series, metabasites, mineralogy, geochemistry, geodynamics, Sredinnyi crystalline massif, Kamchatka. O.S. Urman, O.S. Dzyuba, G.L. Kirillova, B.N. Shurygin Buchia faunas and biostratigraphy of the Jurassic–Cretaceous boundary deposits in the Komsomolsk section (Russian Far East) Representatives of the genus Buchia (Bivalvia, Buchiidae) are abundant in distribution in the Upper Volgian–Lower Valanginian sediments of Northern Sikhote-Alin (Russian Far East). The authors studied them in the key section on the Amur River right bank opposite the city of Komsomolsk. Based on the analysis of the stratigraphic range of the Buchia assemblages, the sequence of beds with Buchia was identified, which can be well correlated with the successions of Buchia zones in many Arctic regions. Here from the bottom Buchia terebratuloides beds, B. unschensis–B. terebratuloides beds, B. volgensis beds, and B. inflata–B. keyserlingi beds have been established. The Berriasian ammonite Pseudosubplanites? sp. of the Tethyan affinity has been recorded in the B. unschensis–B. terebratuloides beds. The presence of a large synclinal fold here has been supported by paleontological evidences. Age ranges for local lithostratigraphic units are defined more precisely. Key words: bivalves, Upper Jurassic, Lower Cretaceous, biostratigraphy, Far East. S.V.
Rasskazov, T.A. Yasnygina, I.S. Chuvashova
Mantle sources of the Cenozoic volcanic rocks of East Asia: Derivatives of slabs, sublithospheric convection and lithosphere A spatial-temporal analysis of the trace elements and Sr isotopic composition ratios was made for volcanic rocks of the Middle-Late Cenozoic continental margin of East Asia. Heterogeneity of sublithospheric mantle was characterized with establishing active sources of supraslab parts of the mantle, Southern and Northern sublithospheric convective subdomains of the Trans-Baikalian low-rate domain at the deep-sea level of 410-200 km. The supply of the isotope homogenous material of convective subdomains was replaced in space and time by the supply of the material of mixed composition. Highly isotope-depleted material was supplied from the mantle areas above the Kula-Izanagi and Pacific slabs ~43.5, 23-17 and < 15 Ma ago, moderately isotope-depleted material – from Northern and Southern convective subdomains ~ 37, 31-23, ~ 16 Ma ago and 1912 Ma ago, respectively. Similar convective but less deep isotope-enriched material was observed in mixed material from the Southern convective subdomain in NE Japan arc in the range of 30 to 9 Ma ago, and in the central Heilongjiang Province, NE China, in the mixtures with isotope-enriched material of the lithosphere < 9.6 Ma ago. Lithospheric melts were erupted at the boundaries of abrupt changes in the dynamics of the sublithospheric convective subdomains. Key words: Cenozoic, basalts, trace elements, Sr isotopes, East Asia.
V.V. Kulakov
Geological-structural and hydrothermal conditions for the formation of groundwater in Priamurye The thermal spas distribution and conditions for their manifestation in Priamurye have been analyzed. The geological-structural model of unloading areas and geothermal depth circulation-influenced conditions of the formation of thermal groundwater were characterized by the example of the extensively investigated Annensky and Kuldur thermal spas. Key words: thermal groundwater, geological-structural features, formation conditions, Priamurye. V.V. Ratkin, V.I. Gvozdev, O.A. Karas’ Boron-polymetallic metallogeny of the northern and northeastern Sino-Korean craton On the basis of published data and original investigations it has been shown that for metallogenic belts of the north and northeastern Sino-Korean craton the combination of widely known Fe, Fe-Mn ores, Au-deposits and unique boron, lead-zinc world class deposits is typical. Here the ore-forming processes have been spatially inherited from Archean to Mesozoic times. The Archean metallogenic belts are related with protocontinental margin terranes îf the craton basement and include the banded iron formation (BIF) and volcanogenic Ñu-Zn massive sulfide deposits. The Proterozoic - Early Paleozoic metallogenic belts are the rift basins where volcanic and sedimentary rock assemblages covered the folded Archean ore-bearing basement. Proterozoic metallogenic belts contain Au in shear-zone and quartz-vein deposits, BIF and sedimentary Fe-Mn deposits, major sedimentary-metamorphic borate and magnesite deposits, tourmalinite-hosted Cu-W deposits, sedimentary exhalative Pb-Zn (SEDEX) deposits, and large polygenic REE-Fe-Nb deposits. The Riphean and Cambriam terrigenous carbonaceous strata are characterized by the presence of stratiform Pb-Zn and fluorite deposits. The Mesozoic metallogenic zones associated with volcano-plutonic complexes of intraplate series exhibit the same inheritance and coincide with the zones where the basement consists of Precambrian ore-bearing sequences. Au-deposits are typical for all metallogenic belts but their most part is connected with Mesozoic volcano-plutonic complexes. Key words: rift, metallogeny, deposits, iron, lead, zinc, boron, fluorite, gold, ñraton, Sino-Korean. A.V. Kudymov, P.A. Koltun, G.A. Zlobin Structure forming processes in the north-eastern zone of the Kolumbinsky fault (the Northern Sikhote-Alin) The dominant sinistral strike-slip movement along the Kolumbinsky fault was recognized through the reconstruction of stress fields as well as using the method of belts in distributing orientations of slickensides and dyke-hosting faults. This movement was triggered by the regional-scale SES-NWN-oriented compression. Migmatites of the Eastern Sikhote-Alin volcano-plutonic belt are considered as formations synchronous with the regional displacement. In line with V.P. Utkin, they are inferred to be of rifting strike-slip and pull-apart nature. Based on the structural and tectonic position of volcanic rocks and accompanying intrusions as well as other general geological data, several stages of dislocation are recognized in the postaccretionary history of the Kolumbinsky fault and the area under consideration. At the end of these stages, the predominant strike-slip motion along the fault and feathering it displacements were replaced by synchronous transpressional and normal faulting. Key words: stress fields, sinistral strike-slip movement, the Kolumbinsky fault, the Northen Sikhote-Alin, the Far East of Russia. A.A. Golieva, L.A. Matyushkina, G.V. Kharitonova, V.S. Komarova Phytoliths in meadow soils of the Middle Amur Lowland The study results of silic phytoliths in the meadow soils of the Middle Amur Lowland are analyzed. Phytoliths observed in the soil profile of the meadow andromeda are arranged based on their belonging to the following plant groups: dicotyledonous grasses, forest and meadow cereals, pine-needles, half-bog (reed, rush), and unspecified plants of dry-steppe flora. The analysis of their content, species diversity and correlation of forms made it possible to assess the specific features of formation of the meadow soils profile, the present and the former phytocenoses. Key words: phytoliths, soils, Far East of Russia. |