Volume 29, 1, 2010 |
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D.V. Kovalenko, O.O. Stavrova, N.V. Tsukanov. Isotopic and geochemical features of the Late Cretaceous and Cenozoic flysch complexes of Kamchatka and southern Koryakia 3 S.V. Rasskazov, T.A. Yasnygina, N.N. Fefelov, Ye.V. Saranina. Geochemical evolution of Middle-Late Cenozoic magmatism in the northern part of the Rio-Grande rift, western USA 15 V.Ye. Kirillov. Experience in classification of ore-bearing metasomatic and hydrothermal rocks, eastern part of the Aldan-Stanovoy shield 44 N.V. Miroshnichenko, Ye.V. Perevoznikova. The intermetallic compound Ni3Au, and solid solutions of gold and nickel in the metalliferous sediments of the Triassic chert formation of the Sikhote-Alin 60 T.V. Volodkova, V.Ya. Podgorny. Geologic-geophysical characteristics of hot spots of Priamurye 67 N.A. Kharitonova, G.A. Chelnokov, Ye.A. Vakh, A.A. Karabtsov, N.N. Zykin. Geochemistry of carbonated mineral waters of the Fadeevskiy occurrence (Primorye) 83 O.F. Lukhneva, F.L. Zuev, V.K. Balkhanov. Construction of the maps of the inhomogeneities of topography on the basis of fractal dimension (as exemplified by the Baikal region) 97 Discussion I.V. Kemkin, A.N. Filippov. A response to S.V. Zyabrev's critical paper "Biostratigraphy of the Far East accretionary complexes (critical review of several papers)" 103 Jubilees Valentin G. Moiseenko (80th birth anniversary) 107 Ruslan G. Kulinich (75th birth anniversary) 108 D.V. Kovalenko, O.O. Stavrova, N.V. Tsukanov Isotopic and geochemical features of the Late Cretaceous and Cenozoic flysch complexes of Kamchatka and southern Koryakia Isotopic and geochemical investigations of Late Cretaceous - Cenozoic flysch thicknesses of Kamchatka and Koryakia show that the thicknesses resulted from at least two sources – depleted and enriched. The enriched source is, evidently, the ancient upper continental crust. The suprasubduction and oceanic complexes can be the depleted source. The enriched rocks predominate in pre-collision flysch thicknesses; and the depleted rocks, in post-collision flysch thicknesses. S.V. Rasskazov, T.A. Yasnygina, N.N. Fefelov, E.V. Saranina Geochemical evolution of Middle-Late Cenozoic magmatism in the northern part of the Rio-Grande rift, western USA Geochemical studies of the Middle-Late Cenozoic succession of volcanic rocks from the northern part of the Rio-Grande rift were conducted. The initial activation of the rift structure was coeval to voluminous eruptions of lava and pyroclastic material of mainly intermediate and acid composition on the San Juan volcanic field 35-27 million years ago. The composition of the subsequent volcanic products that accompanied rifting was dominated by basic and intermediate lavas. It is shown that basanites and alkali basalts of the territory had geochemical characteristics of sub-lithospteric and above-slab sources. The processes of rifting-caused thinning of the lithosphere are expressed by geochemical parameters reflecting interaction between liquids from the sub-lithospheric mantle and rocks from different levels of both the lithospheric mantle and the lower crust. In the 35-18 Ma interval, melts of different-depth sub-lithospheric and lithospheric sources erupted simultaneously in the northern part of the rift but afterwards, in the past 15 Ma, products of interaction between sub-lithospheric and lithospheric material dominated, although sub-lithospheric magmatic liquids erupted in the northern structural termination of the rift, within the Yampa volcanic field, at about 10 Ma. V.Ye. Kirillov Experience in classification of ore-bearing metasomatic and hydrothermal rocks, eastern part of the Aldan-Stanovoy shield This work systemizes the available fund and literature information, and also the author’s results of investigation of ore-bearing metasomatites in the eastern part of the Aldan-Stanovoy shield. It also typifies metasomatites based on the formation they belong to. Data on the age, structure location, mineral composition features, metallogenic specialization, and genesis of the ore-bearing formations is given, and patterns of their spatial distribution are considered. N.V. Miroshnichenko, Ye.V. Perevoznikova The intermetallic compound Ni3Au, and solid solutions of gold and nickel in the metalliferous sediments of theTriassic chert formation of the Sikhote-Alin The intermetallic compound Ni3Au and the solid solutions of Au and Ni – native nickel Au and Au-bearing native Ni were found in the contact metamorphosed metalliferous sediments of the Triassic chert formation of the Sikhote-Alin. The metalliferous rocks are characterized by high content of Au, Ag, and PGE and by presence of diverse minerals of precious metals. Nickel gold (Au0.91-0.88Ni0.09-0.12) is found in the form of grains and crystals measuring 3-4 mkm in gold-bearing cherts with hematite (“itabirites”) and in the altered siliceous rocks of the Dal’nerechenskiy district (Gornaya River upper reaches). Together with it, the so-called “copper Au”, admixture-free native Au (Au1.00), and solid solutions of Au and Ag (Au0.86-0.84Ag0.14-0.16), and Au, Ag, and Pb (Au0.78Ag0.19Pb0.03) occur. Au-bearing Ni is found in metamorphosed mudstone (“ilmenite-biotite-feldspar”) and in “itabirites” of the Shirokopadninskaya area in the Olginsky district. In the metamorphosed mudstone, Au content in some grains (about 10-15 mkm in diameter) of this mineral varies from 6.09 (Ni0.98Au0.02) to 11.30 mass % (Ni0.96Au0.04). Grains of Au-bearing Ni (Co0.001-0.00Au0.02-0.17Ni0..98-0.83) in “itabirites” are also heterogeneous in composition and contain fine impregnations of the Ni3Au intermetallic compound (based on the analysis – Ni2.99Au1.01). T.V. Volodkova, V.Ya. Podgorny Geologic-geophysical characteristics of hot spots of Priamurye Models of dead and present-day hot spots of Priamurye have been constructed based on seismogravitational modeling and large-scale aerogeophysical survey along with other geologic-geophysical materials. Mechanisms of the change of the deep structure of the hot spots and Maya-Selemdzha plume in the course of evolution are considered , and also some features of the related ore districts are examined. N.A. Kharitonova, G.A. Chelnokov, Ye.A. Vakh, A.A. Karabtsov, N.N. Zykin Geochemistry of carbonated mineral waters of the Fadeevskiy occurrence (Primorye) A geochemical study was made of water-bearing rocks, underground and surface waters, and also attendant gasses of the Fadeevskiy occurrence of carbonated waters (Sikhote-Alin, Primorye). It has been established that the chemical composition of mineral waters formed in the zone of active water exchange on a limited area of the discharge zone, where the rocks of mainly K-Na composition give birth to hydrocarbonate calcium waters with mineralization up to 1.0 g/l. The calculated indices of saturation show that the mineral waters are at the initial stage of Ca saturation and are undersaturated with both carbonates and aluminum silicates. Major factors governing water mineralization are the presence in the water of excess carbon dioxide and circulation time. The study of the oxygen and hydrogen isotope ratios in water indicates an atmospheric genesis of the water component (d2H = -117; d18O = -15.4 ‰), and the values of the CO2 carbon isotope suggest the mantle nature of carbon dioxide (d13Ñ = -9.9). O.F. Lukhneva, F.L. Zuev, V.K. Balkhanov Construction of the maps of the inhomogeneities of topography on the basis of fractal dimension (as exemplified by the Baikal region The paper attempts to derive new scientific information on principle by mathematical processing of the digital model of the Baikal region relief by the methods of fractal analysis. The system of rose-profiling is offered, which allowed recognition of fractal dimension for the separate sections of relief. The maps of distribution of fractal dimension of topography were generated, and the map of asymmetry of relief of the study region was developed. The offered methodical approach involving fractal analysis made it possible to have maps of zoning of the territory based on the fractal feature. |