Òîì 31, 3, 2012 |
| V.S. Vishnevskaya, N.I. Filatova. Marine
allochthonous Mesozoic deposits of Northeastern Asia and Northwestern
America: correlation of age levels and geodynamic conditionsof
accumulation 3 E.P. Terekhov, A.V. Mozherovsky, I.B. Tsoy, E.P. Lelikov, N.G. Vaschenkova, M.T. Gorovaya. Late Cretaceous and Cenozoic volcanogenic-sedimentary rocks of the submarine Vityaz Ridge (Island slope of the Kuril-Kamchatka trench) and its evolution 24 M.E. Melnikov, S.P. Pletnev, T.E. Sedysheva, T.A. Punina, V.D. Chudik. New data on the structure of the sedimentary cover of the Ita Mai Tai Guyot (the Magellan Mountains, the Pacific Ocean) 32 A.V. Kudymov, S.A. Medvedeva. The provenance of the Middle Jurassic-Lower Cretaceous deposits of Lower Priamurye 46 E.L. Shkolnik, E.A. Zhegallo. On the conditions of formation of some iron ores in the Uda-Shantar Basin, Far East Region 59 G.Yu. Pavlova, P.Ya. Tishchenko, N.D. Khodorenko, M.G. Shvetsova, S.G. Sagalaev. The major ion composition and carbonate equilibrium in the sediment pore water of the Razdolnaya River estuary (Amur Bay, the Sea of Japan) 69 G.V. Kharitonova, N.P.Chizhikova, A.S.Manucharov, N.S.Konovalova. Interaction of soluble salts with clay minerals 81 V.I. Roslikova, A.B. Gyninova. Transformation of solid phase of texture-differentiated soils of Middle Priamurye as a result of drainage meliorations, and diagnostic implication of Mn-Fe concretions in this process 93 V.S. Vishnevskaya, N.I. Filatova Marine allochthonous Mesozoic deposits of Northeastern Asia and Northwestern America: correlation of age levels and geodynamic conditionsof accumulation Correlation of discreted in area outcrops of Middle Mesozoic allochthonous deposits of Northeastern Asia and Western America includes some problems: stratigraphic division of the rocks based on the radiolarian method considering complicated overthrust nappe structure of the region; characteristics of facial composition of the deposits, and geodynamic conditions of their accumulation; determination of the degree of community of discrete outcrops of the Mesozoic allochthonous deposits pertaining to the above two aspects. The radiolarian analysis used extensively for the first time has shown that Middle Mesozoic marine rocks of some slices and scales of tectonostratigraphic sections in East Asia include 20 different-aged radiolarian assemblages in the span from the Norian to Hauterivian inclusively. The correlation of these assemblages has revealed a wide lateral development of the deposits, containing them, within the studied regions. The importance of the present paper is the following: (1) marine Middle Mesozoic deposits of Northeastern Asia have been first subdivided into stages and substages based on the radiolarian method which is in agreement with western North America; (2) large-scale development of stratigraphic units within Northeastern Asia has been confirmed by correlation in spite of discrecity of Mesozoic allochthonous outcrops; and (3) affiliation of the deposits to a wide range of geodynamic settings (different areas of the oceanic bottom, island arcs, forearc and marginal marine basins) has been revealed, and the different-typed rocks were also traced practically throughout the studied territory of East Asia. Key words: correlation of Mesozoic allochthons, radiolarian analysis, petrologo-lithological methods, Northeastern Asia, Northwestern America. E.P. Terekhov, A.V. Mozherovsky, I.B. Tsoy, E.P. Lelikov, N.G. Vaschenkova, M.T. Gorovaya Late Cretaceous and Cenozoic volcanogenic-sedimentary rocks of the submarine Vityaz Ridge (Island slope of the Kuril-Kamchatka trench) and its evolution Volcanogenic-sedimentary rocks of different ages (Late Cretaceous-Early Paleocene, Paleocene-Eocene (?), Oligocene-Early Miocene, and Pliocene-Pleistocene) forming the basement and sedimentary cover of the submarine Vityaz Ridge are described. Different material composition of the Upper Cretaceous sedimentary rocks of the Vityaz Ridge basement (“sialic”) and the Lesser Kuril Range (“mafic”) was determined. Mineral associations of the matrix reflecting smectite and corrensite stages of the Cenozoic rocks epigenesis are distinguished. The Late Cretaceous-Pleistocene geological evolution of the region is offered. Key words: volcanogenic-sedimentary rocks, Late Cretaceous, Cenozoic, authigenic minerals, diatoms, palynoflora, submarine Vityaz Ridge, Kuril-Kamchtka Trench. M.E. Melnikov, S.P. Pletnev, T.E. Sedysheva, T.A. Punina, V.D. Chudik New data on the structure of the sedimentary cover of the Ita-Mai-Tai Guyot (the Magellan Mountains, the Pacific Ocean) Expeditionary investigations carried out by SSC “Yuzhmorgeologiya” in 2003-2010 on board of R/V “Gelendzhik” within the eastern branch of the Magellan Mountains in the Pacific Ocean allowed to obtain new materials pertaining to the structure of the relief of the Ita-Mai-Tai Guyot and the rocks which constitute it from the Early Cretaceous to Pleistocene inclusive. The guyot has a complex irregular shape with angular contour and is complicated by numerous relief mezoforms– spurs, terraces, volcanic cones and domes. A long-term history of the sedimentary cover formation has been recognized. The analysis of macro- and microfaunal organic remains in the sedimentary rocks enabled to distinguish transgressive phases in the development of the guyots (Albian–Cenomanian, Late Campanian–Maastrichtian and Late Paleocene–Early Eocene). The geological age of the oolite limestones disclosed by the borehole 202 DSDP, corresponds to Aptian-Albian. Based on the results obtained by the authors and the previous publications, the conditions of geological evolution of the Ita-Mai-Tai Guyot were compared with other guyots of the Magellan Mountains. Key words: Cretaceous, Cenozoic, organic remains, magmatic and sedimentary rocks, guyots, Pacific Ocean, Magellan Mountains. A.V. Kudymov, S.A. Medvedeva The provenance of the Middle Jurassic-Lower Cretaceous deposits of Lower Priamurye Studies on petrographical and chemical composition of the Middle Jurassic-Lower Cretaceous deposits of Lower Priamurye have revealed that granitoids played an important place in the provenance. Among the sedimentary rocks, intermediate intrusions and mafites, sedimentary, volcanic, metamorphic, and ophiolite (?) complexes are less common. Cross bedding orientation and casts of whirlpool pits in the Volginian-Valanginian turbidites corroborate the position of the provenance in the west and southwest. These are mostly continental granite-metamorphic blocks of the Jiamusi-Khanka-Bureya Massif. In addition, fragments of Upper Paleozoic-Lower Mesozoic continental active margin and island volcanic arc were crucial in the composition of the provenance. Key words: provenance, chemical composition, sandstones, Middle Jurassic-Lower Cretaceous, Lower Priamurye. E.L. Shkolnik, E.A. Zhegallo On the conditions of formation of some iron ores in the Uda-Shantar Basin, Far East The present paper describes the first results of SEM-study of some varieties of iron ores of the Far East Uda-Shantar Basin, the Far East Russia. The presence of various microbial remains mineralized by Fe and Mn compounds was identified in the ores. Key words: iron ores, SEM, Uda-Shantar Basin, Far East. G.Yu. Pavlova, P.Ya. Tishchenko, N.D. Khodorenko, M.G. Shvetsova, S.G. Sagalaev The major ion composition and carbonate equilibrium in the sediment pore water of the Razdolnaya River estuary (Amur Bay, the Sea of Japan) In February of 2010 complex investigations of river water and sediment pore water were conducted in the downstream of the Razdolnaya River. The major ion composition suggests that in winter season bottom waters and sediment pore waters in the downstream of the river are of the sea origin. Geographically, the estuary of the Razdolnaya River stretches upstream for a distance of more than 20 km. It has been established that the studied sediments are deoxidated silt sediments highly enriched in iron sulfide minerals (pyrite, hydrotroilite, monosulfide) evidence ing the sulfate reduction process in the studied sediments. Early diagenesis of organic matter accounts for sulfate ion reduction and alkalinity increase in the sediment pore water. Pore water of the sediments from deep bottom pits was highly alkaline that cannot be explained by sulfate reduction and methane genesis. It was supposed that chemical silicate weathering and bacterial mineralization of the organic acid salts may cause abundance of alkalinity in the studied sediment pore water. Key words: major ion composition, carbonate equilibrium, organic matter, pore water of anoxic sediments, marginal filter, estuary, Razdolnaya River, Amur Bay, the Sea of Japan. G.V. Kharitonova, N.P. Chizhikova, A.S. Manucharov, N.S. Konovalova Interaction of soluble salts with clay minerals The interaction of soluble salts NaCl, MgCl2, Ca(CH3COO)2, ZnCl2 and Pb(CH3COO)2 with clay minerals (kaolinite and smectite) was studied by the methods of optical and scanning electron microscopy. It was shown that the interaction of soluble salts with clay minerals leads to changes in the mineral particle organization and formation of clay-salt micro-aggregates. The intensity of the process of clay-salt micro-aggregate formation, their stability, as well as packing, shape and size of the particles depend on the nature of mineral and interacting salt characteristics. Key words: clay minerals, soluble salts, clay-salt micro-aggregates. V.I. Roslikova, A.B. Gyninova Transformation of solid phase of texture-differentiated soils of Middle Priamurye as a result of drainage meliorations, and diagnostic implication of Mn-Fe concretions in this process The paper present the results of long-standing examinations of texture-differentiated soils drained for a long time by closed tile drainage using complex of methods including micromorphological and concretion analysis methods. The diagnostic indications of soil transformation in different parts of the catena soils are defined. Key words: soil, catena, concretions, closed drainage, micromorphological structure. |