Том 31, 5, 2012 |
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A.I. Khanchuk, I.Yu. Rasskazov, T.N. Alexandrova, V.S. Komarova.
Natural and technological typomorphic associations of minor elements in
carbonaceous rocks of the Kimkansky ore manifestation of
precious metals, Far East 3 A.S. Biakov. New zonal scheme of the Permian deposits of Northeast Asia from bivalved mollusks Paper 1.Zonal sequence 13 А.М. Petrishchevsky, Yu. P. Yushmanov. Metallogeny of deep structures of the Earth Crust in Southern Sikhote-Alin (evidence from gravity data) 41 A.V. Maslov, V.N. Podkovyrov, E.Z. Gareev. To the evaluation of paleogeodynamic settings of formation of Lower and Middle Riphean sedimentary sequences of the Uchuro-Maya region and Bashkir meganticlinorium 55 A.G. Vladimirov, P.A. Balykin, Phan Lyu Anh, N.N. Kruk, Ngo Thi Phuong, A.V. Travin, Tran Trong Hoa, I.Yu. Annikova, M.L. Kuybida, E.V. Borodina, I.V. Karmysheva, Buy An Nien. The Khao Que-Tam Tao gabbro-granite massif (Northern Vietnam) – petrological indicator of the Emeishan Plume 69 B.V. Levin, Chun Un Kim, V.N. Solovjev. Seismic hazard estimate and results of detailed seismic zoning for the cities of Sakhalin Island 93 Г.Н. Копылова, С.В. Болдина. О механизме гидрогеодинамического предвестника Кроноцкого землетрясения 5 декабря 1997 г., MW = 7.8 104 И.С. Литвиненко. Золотоносность ледового комплекса пород в южной части Анюйской впадины (Западная Чукотка) 115 A.I. Khanchuk, I.Yu. Rasskazov, T.N. Alexandrova, V.S. Komarova Natural and technological typomorphic associations of minor elements in carbonaceous rocks of the Kimkansky ore manifestation of precious metals, Far East The paper presents the results of mineralogical-technological examination of carbonaceous rocks of the Kimkansky ore manifestation of precious metals. On the basis of these results new typomorphic natural and technological minor element associations were revealed using mathematical statistical criteria. Keywords: carbonaceous rocks, enrichment, minor elements, flotation, statistical criteria. A.S. Biakov New zonal scheme of the Permian deposits of Northeast Asia from bivalved mollusks. Paper 1. Zonal sequence Extensive new evidence have been obtained in the recent decade for a number of reference sections for the Permian Northern, Western and Southern Verkhoyanie, Balygychansky Block, and Omolon Massif along with some adjacent regions which allowed substantial detailing zonal scheme of the Permian deposits of Northeast Asia from bivalve mollusks. In the renewed scheme there are 24 fractional biostratones within zones, subzones, and beds with fauna. Zonal assemblages of bivalved mollusks have been considerably specified and added, and the age of the zones was improved and justified. Stratigraphic range of the bivalve taxons identified is given in the accompanying table. Keywords: Permian, bivalved mollusks, zones, subzones, beds with fauna, Northeast Asia. А.М. Petrishchevsky, Yu. P. Yushmanov Metallogeny of deep structures of the Earth crust in Southern Sikhote-Alin (evidence from gravity data) Spatial relations between ore deposits of the Sikhote-Alin and deep dense inhomogeneities of the Earth crust up to depth of 30 km have been examined. Discrete correlation of ore areas and regions with anomalies of normalized density of equivalent spherical sources of gravity anomalies at depths of 1-2, 4-5, 10-12 and 24 km presumably caused by magmatic bodies with different composition of initial magmas, is revealed. The depth of magmatic bodies with intermediate to basic matter composition, and a vertical range of their correlation with ore regions depend on their structural position, and it decreases southeastward. Deep ranges of magmatic bodies of granitic and mixed composition are correlated with metallogenic specialization of the corresponding ore-magmatic systems. Tin-ore systems are characterized by a smaller range (5-10 km) of relations with dense inhomogeneities, whereas tin-tungsten-gold ones are marked by a wider range (20-25 km). Tin-lead-zinc systems occupy an intermediate position (12-20 km). Ore-controlling role of the boundaries between structural-formational complexes of the Earth crust and central type structures in the distribution of the deep sources of ore mineralization is shown. Keywords: gravity modeling, Earth crust deep structures, metallogeny, Sikhote Alin. A.V. Maslov, V.N. Podkovyrov, E.Z. Gareev To the evaluation of paleogeodynamic settings of formation of Lower and Middle Riphean sedimentary sequences of the Uchuro-Maya region and Bashkir meganticlinorium Examples of Lower and Middle Riphean (Mesoproterozoic) deposits of the Uchuro-Maya region (Far East) and Bashkir meganticlinorium (Southern Urals) illustrate the possibility of using a series of widely known normalized discrimination diagrams (K2O/Na2O–SiO2/Al2O3, SiO2–K2O/Na2O, (Fe2O3*+MgO)–TiO2, F1–F2, Th–La–Sc, Sc–Th–Zr/10 and Sc/Cr–La/Y) for determining the paleogeodynamic settings of the formation of the sedimentary strata. It is shown that only some of them may be used with one or other degree of reliablity to reconstruct settings of the formation of platform sedimentary sequences composed of both sandstones and fine-grained clastics. Keywords: Riphean, lithogeochemistry, paleogeodynamic reconstructions, Uchuro-Maya region, Bashkir meganticlinorium. A.G. Vladimirov, P.A. Balykin, Phan Lyu Anh, N.N. Kruk, Ngo Thi Phuong, A.V. Travin, Tran Trong Hoa, I.Yu. Annikova, M.L. Kuybida, E.V. Borodina, I.V. Karmysheva, Buy An Nien The Khao Que-Tam Tao gabbro-granite massif (Northern Vietnam) – petrological indicator of the Emeishan plume New data obtained for the Khao Que-Tam Tao gabbro-granite pluton (Northern Vietnam) are discussed. It was established that this pluton was formed at the Permian-Triassic boundary (250.5±3.2 Ma, 40Ar/39Ar isotope age). Its morphology represents fracture hypabyssal intrusion. Picrobasaltic melt was intruded during the first stage, differentiation of which resulted in the formation of stratified peridotite-gabbro series and at the endocontacts in the final differentiates represented as quartz-bearing monzodiorite and granophyre. Deformation break has occurred on the axis of the Khao Que peridotite-gabbro massif, and the Tam Tao granodiorite melt was intruded at the second stage. Mathematical modeling using COMAGMAT program and geochemical estimation for the granite system allow the statement that magmatic melts are consequence of the independent differentiation, the end-products of which were quartz-bearing monzodiorite and granophyre on the one part, and aplite and pegmatite on the other part. Correlation of the composition of the Permian-Triassic magmatic associations in the Northern Vietnam (Nui Chua gabbro pluton, Khao Que-Tam Tao gabbro-granite and Pia Biok granite plutons) and in the Southeast China (platobasalts) allows these complexes to be viewed as a part of a single large igneous province originated from the Emeishan plume activity. Keywords: Southeastern Asia, Northern Vietnam, Emeishan plume, petrological indicators, gabbro-granite series, Ar/Ar isotope age, Permian-Triassic, mantle and crust sources, geodynamical model. B.V. Levin, Chun Un Kim, V.N. Solovjev Seismic hazard estimate and results of detailed seismic zoning for the cities of Sakhalin Island The paper briefly deals with the basics of probabilistic seismic hazard analysis (PSHA). Special attention is paid to identification and quantitative estimation of uncertainties associated with description of seismic sources and engineering models for prediction of strong motions Basic seismic models and results of implication of PSHA for detailed seismic zoning for the territories of the Sakhalin cities are offered. Keywords: seismicity, seismic hazard, logic tree, disaggregation, seismic zoning, Sakhalin Island. G.N. Kopylova, S.V. Boldina On the mechanism of a hydrogeodynamic precursor of the Kronotsky earthquake, December 5, 1997, MW= 7.8 Fall of water table with amplitudes 11 and 1 cm were registered in the wells UZ-5 and E-1, Kamchatka, within three weeks before the 5th December, 1997 Kronotsky earthquake, Mw=7.8. Such decreases of water level defined as hydrogeodynamic precursor of the earthquake, developed synchronously with horizontal displacements of the GPS-stations located at intervals up to the first hundreds km from the future seismic focus. The mechanism of the formation of the hydrogeodynamic Kronotsky earthquake precursor is discussed with application of the model of the elastic response of water level to the seismotectonic deformation of water-bearing rocks. It was shown that the fall of water table in both wells can be explained by undistorted response of pore pressure to a quasi-elastic volume deformation of the water-bearing rocks as a result of pre-seismic movements at the stage of the Kronotsky earthquake preparation. From the level meter observations in the areas of the wells, the estimated values of pre-seismic expansion of the water-bearing rocks are Dt = (0.6–0.8)×10-7 . Keywords: Kronotsky earthquake, well, water-bearing rock, water table, tidal sensitivity, deformation, seismic focus, precursor. I.S. Litvinenko Gold of the ice rock complex in the southern Anyui basin (Western Chukotka) The presence of gold in the sandy-loam, silty, and loamy rocks with abundant amount of ice in the southern part of the Anyui basin and river valleys on its margin were investigated with special enrichment equipment (spiral separator and sluice). The formations under consideration were formed under subaqueous conditions of shallow-water low-circulating water reservoirs. A total ice thickness attains to 70%. The size of the enclosed terrigenous material is reduced from basin rocks to its central parts (the river valleys are composed mainly of fine-sand and silt fractions, silt and pelitic fractions are observed in the outlying districts of the Anyui basin, and pelitic ones are marked in the central parts of the basin). It is characterized by a relatively high maturity and presence (in the Anyui basin) of the authigenic siderite in abundance (up to 69%). In the clayey fraction, apart from hydromica, montmorillonite, chlorite, kaolinite, and halloysite, fragments of diatoms have been identified. The participation in the formation of ice complex of the material of the Prepliocene crust of the chemical weathering with relicts of illuvial-remnant gold concentrations conditioned their gold placer. In the river valleys on the basin margin within ore fields they are in a varying degree auriferous the entire area and its whole thickness. The determined clastic gold contents are 0.6gr/m3. Average contents of the metal on the enriched areas are estimated as 0/2-0.3 gr/m3. Free gold averages 77.7% and is represented by fine (less than 0.5 mm) extractions. The bulk of the “related” gold is concentrated in a light fraction in the grains less than 0.1 mm. Gold content in excess of 43 % of samples above the content of the established clastic gold indicates the presence of considerable dust-like and fine-dispersed extractions in the formations. Directly in the Anyui basin in the ice rocks the clastic gold has not been revealed. Atomic-absorption analysis showed the gold content in them up to several tens of mg/m3. Key words: ice rocks, placer, gold, NE Russia. |