Volume 27, 1, 2008 |
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I.N. Tikhonov, N.F. Vasilenko, D.E. Zolotukhin, T.N. Ivelskaya, A.A. Poplavsky, A.S. Prytkov, A.I. Spirin. Simushir earthquakes and tsunami of November 15, 2006 and January 13, 2007 3 V. S. Rozhdestvenskiy. Active rifting in the Japan and Okhotsk Seas, and tectonic evolution of the Central Sakhalin fracture zone in Cenozoic 17 Ye.E. Tyukova, S.V. Voroshin. Sulfur isotope composition of sulfides from the ores and host rocks of the Upper Kolyma region (Magadan area) 29 V. G. Gonevchuk, G.A.Gonevchuk. Composition and genesis of the intrusive association of the Magloy magmatic area (Central Priamurye) 44 I.M. Derbeko, A.A. Sorokin, S.G. Agafonenko. Geochemical peculiarities of acid magmatism in the north-western part of the Khingan-Okhotsk volcano-plutonic belt (Aezop and Jam-Alin zones) 60 A.I. Miroshnichenko, A.P. Sorokin, V.A. San’kov, A.V. Lukhnev, S.V. Ashurkov, A.T. Sorokina, N.I. Panfilov, M.A. Serov, S.I Sherman. Space geodesy in the issues of geodynamics: present-day movements in the Zeya-Bureya Basin 71 I.V. Tibilov. Geologic-and-petrographic evidence for the autochthonous nature of the Late Mesozoic small intrusions of Chukotka 80 G.F. Ufimtsev. Under-ice mountains 97 V.V. Kulakov, L.M. Kondratyeva. Biochemical aspects of underground water purification in Priamurye 109 Reviews V.G. Khomich. Gold and silver metallogeny of the Okhotsk-Chukotka volcanogenic belt 119 Jubilees Pavel G. Korostelev. 80th birth anniversary 127 I.N. Tikhonov, N.F. Vasilenko, D.E. Zolotukhin, T.N. Ivelskaya, A.A. Poplavsky, A.S. Prytkov, A.I. Spirin Simushir earthquakes and tsunami of November 15, 2006 and January 13, 2007 The earthquakes and tsunami on November 15, 2006 and January 13, 2007 near Simushir Island are described. Long-term and short-term precursor phenomena are discussed. Joint analysis of seismological and geodetic data provided reliable interpretation of mechanisms of seismic foci. The actions of the tsunami prevention personnel are analyzed. Extensive evidence of tsunami occurrence at different sites of the Pacific Ocean is described. The numerical modeling of tsunami of November 15, 2006 is carried out using the coseismic vertical displacement of the ocean bottom estimated from GPS data. The actual and model data about maximal tsunami run-up are compared. V. S. Rozhdestvenskiy Active rifting in the Japan and Okhotsk Seas, and tectonic evolution of the Central Sakhalin fracture zone in the Cenozoic Using the structural analysis of large-scale geologic maps of separate regions and geologic-geophysical maps of Sakhalin and the adjacent seas, we discuss the tectonic evolution of the Central Sakhalin fracture zone which was conditioned by crustal block movements during the opening of rift basins. The reorientation of horizontal compression forces from diagonal (northwest–southeast) to sublatitudinal resulted in the transformation of meridional dextral strike-slip faults into reversed faults in the Late Miocene. These facts do not allows us to consider Sakhalin faults as a zone of recent right-lateral shear between the Eurasian and Okhotsk Sea plates. Ye.E. Tyukova, S.V. Voroshin Sulfur isotope composition of sulfides from the ores and host rocks of the Upper Kolyma region (Magadan area) Results of more than 200 sulfur isotope analyses of sulfides from various host rocks (terrigenous and intrusive), wallrock alterations and lode deposits of the Upper Kolyma region are presented. Sulfur isotopes in accessory pyrite of the metatubidites change from -23.1 to +5.7‰ d34S. The pyrite and arsenopyrite isotope composition of gold quartz mineralization falls into an interval of -10,6 to -0.4‰ 34S with the average values close to d34S of pyrite from metatubidites (-4,4). In intrusive rocks the values of d34S in pyrite change from -3,8 to + 2.6‰, the average value being +0,7‰, which differs essentially from the values of 34S in arsenopyrite of postmagmatic gold – rare metal mineralization (-7.9 to -2.7‰; with the average value -5.2‰ d34S). The comparison of d34S of accessory sulfides of the host rocks with 34S sulfides at the gold deposits suggests participation of sulfur, mobilized from the terrigenous strata, in the hydrothermal process. The results achieved are conformable with the metamorphogenic model of genesis for the gold-quartz deposits of the Upper Kolyma region. V. G. Gonevchuk, G.A.Gonevchuk Composition and genesis of the intrusive association of the Magloy magmatic area (Central Priamurye) Results of new geochemical and isotope-geochronological research into the intrusive association are given for one of the largest and comparatively poorly investigated zone of Cretaceous (Aptian-Cenomanian) magmatism of the Sikhote-Alin accretionary fold system. The petrological interpretation of the available and earlier data is made on the basis of conceptions of the block (terrane) structure of the region and different geodynamic nature of magmatic complexes. It is shown that "transitive" characteristics of the investigated intrusive rocks in geochemical and geodynamic classifications can be explained by the magmatism model of the transform continental margin. The influence of the terrane composition and the change of the geodynamic regime in the region, which falls on the time of formation of the study area (114-90 Ma), are considered as additional complicating factors. I.M. Derbeko, A.A. Sorokin, S.G. Agafonenko Geochemical peculiarities of acid magmatism in the north-western part of the Khingan-Okhotsk volcano-plutonic belt (Aezop and Jam-Alin zones) The paper studies the structure of the Aezop – Yam-Alin area and the composition of its acid volcanic and intrusive rocks. Data on their age are also given. The general geochemical peculiarity of the acid formations is their moderate enrichment in such elements as Rb = 84-268 ppm, Ba = 240-881 ppm, K = 21300-44400 ppm, Th = 10.5-17.9 ppm, and REE. At the same time, they are depleted in Nb = 5-12 ppm, Ta = 0.5-1.2 ppm, and Sr – up to 70 ppm. Age datings have been obtained for granites of the Aezop complex by the U-Pb method (94.8±2.2 Ma) and Rb-Sr method (95.22±0.69 Ma), which corresponds to the Cenomanian. A.I. Miroshnichenko, A.P. Sorokin, V.A. San’kov, A.V. Lukhnev, S.V. Ashurkov, A.T. Sorokina, N.I. Panfilov, M.A. Serov, S.I Sherman Space geodesy in the issues of geodynamics: present-day movements in the Zeya-Bureya Basin The Amur-Zeya geodynamic test ground was set up in 2000 to study present intracontinental deformations of the Earth’s crust. The velocity calculations in the period from 2000 to 2003 describe three large-scale levels of movements. The general level is characterized by the vectors of movement of IGS sites in the eastern part of Asia, including the BLAG (Blagoveshensk) site. The south-eastern movement of the IRKT (Irkutsk) site of the stable Siberian platform is an indicator of deformations in the north-eastern part of the Amur plate. Measurement data on the regional sublatitudinal profile Blagoveshensk – Sutara intersecting the Lower Zeya Basin demonstrate the Badzhal-Bureya-Lesser Khingan block displacement to the south-west of the North China block. The dynamic effect of the convergent boundary of the Amur and the Okhotsk Sea plate is assumed to extend inland covering also the Zeya-Bureya Basin area. The measurements on the local geodynamic test site relate the deformations of buildings and constructions of Konstantinovka Village to the mobility of basement faults in the southern part of the Lower Zeya Basin. Aseismic deformations are determined by slow horizontal tectonic movements in the junction zone of NNE structures of the Lower Zeya Basin and sublatitudinal faults of the Hailar-Xunhei belt. I.V. Tibilov Geologic-and-petrographic evidence for the autochthonous nature of the Late Mesozoic small intrusions of Chukotka The autochthonous nature of Late Mesozoic small intrusions in Chukotka is shown. The geologic and petrographic evidence is offered on the metasomatic (magmatometamorphic-metasomatic) genesis of small intrusions with relation to the old Chukotka relief formation. G.F. Ufimtsev Under-ice mountains The morphological structure of mountains is described, which was formed in conditions of extensive continental and mountain glaciation. They feature a general multiply convex profile with alternation of dome-shaped peaks and steps, valley-shaped lows and microrelief of sheep foreheads and ice-dressed rocks, with nunataks, among which isolated peaks are distinguished as high cones or prisms. Under-ice mountains are represented by a step-like morphological landscape with glaciated steps and leveling planes. An assumption is made that the step structure of the morphological landscape of under-ice mountains can be the result of sequential foliation of ice caps in respect to the rate of their movement and appearance of ice jet flows with the general dominance of areal displacement of ice masses. This makes under-ice mountains morphologically similar to middle-height relief and lowland of the moderate humid belt of the northern hemisphere, on whose slopes mass ground displacements are predominant. V.V. Kulakov, L.M. Kondratyeva Biochemical aspects of underground water purification in Priamurye In connection with the use of underground water with elevated Fe and Mn concentrations for domestic consumption in Piamurye, comprehensive hydrogeochemical and microbiological investigations were undertaken in the 1990s-2000 at underground water intakes, exploratory hydrogeologic and production holes, and at specially set up trial technological underground water in-aquifer purifiers. Work was conducted to access a possibility and efficiency of removal of these components from water directly in the aquifer. The base for underground water purification of Fe and Mn directly in natural conditions is the theory of biological and hydrogeochemical processes in the lithosphere based on creation of anthropogenic biogeochemical barriers and interaction of natural and oxygen-saturated underground waters in the system “water – rock” of the aquifer. |