Volume 30, 1, 2011 |
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A.A. Stepashko. Deep roots of seismotectonics of the Far East: Priamurye and Primorye zones 3 A.T. Sorokina, A.P. Sorokin, M.A. Serov, A.A. Popov. Fault-block structures of the eastern margin of the Amur lithosphere plate, their seismicity and fluid regime 16 V.P. Simanenko, S.V. Rasskazov, T.A. Yasnygina, L.F. Simanenko, A.A. Chashchin. Cretaceous complexes of the frontal zone of the Moneron-Samarga island arc: geochemical evidence of basalts from the deep hole on Moneron Island (Sea of Japan) 30 B.I. Pavlyutkin, I.Yu. Chekryzhov, T.I. Petrenko. Voznovskaya suite as an image of the Early Oligocene stage in the geologic history of the East Sikhote-Alin 52 V.G. Khomich, N.G. Boriskina. Fundamental geologic-genetic types of native gold deposits of the Transbaikal region and the Russia Far East (Discussion by L.V. Eirish) 70 A.A. Lotina. Gold-bismuth-telluric mineralization at the Bolotistoye placer field (North-Western Sikhote-Alin) 97 N.A. Kharitonova, G.A. Chelnokov, Ye.A. Vakh, V.A. Goryachev. Geochemistry of Nizhniye Luzhki carbonaceous mineral deposit (Primorye) 108 Chronicles A.S. Astakhov, K.I. Aksentov, O.V. Belous, T.A. Gulenko, A.J. Zhukovin, V.N.Karnaukh, O.S. Yanovskaya. Geological and geoecological research in the Sea of Japan in Cruise 45 of the R/V “Professor Gagarinskiy” (October–November 2009) 119 Jubilees Gel'man Mikhail L. (80th birth anniversary) 125 Memorial dates Yuriy Alexandrovich Kosygin (100th birth anniversary) 126 Obituary Bespalov Valentin Ya. (1941–2010) 129 A.A. Stepashko Deep roots of seismotectonics of the Far East: Priamurye and Primorye zones The role of the lateral structure of lithosphere mantle in seismotectonics and seismicity of the southern part of the Russian Far East has been investigated. The epicenter position of all major crust earthquakes of Sakhalin with Ì 6.0, and of Priamurye and Primorye with Ì 5.0 is determined by the boundaries of the Anyui block of highly ferruginous mantle which lies in the base of the Sikhote-Alin area. Three cycles of large earthquakes are recognized in the region: end of the XIX – beginning of the XX century, mid-XX century, and end of the XX – beginning of the XXI century. In the Priamurye seismic zone the epicenters of large earthquakes in each cycle migrate from SW to NE along the Tan-Lu fault megasystem at a rate of 30–50° km per annum. The specific features of sesimicity of the region are explained by a repeated arrival of deformation waves from the west which propagate in the upper part of the mantle and cause activation of the deep structure of the region. The detailed analysis of the earthquakes with Ì 4.0 of the Sikhote-Alin area during 1973–2009 confirmed clockwise tectonic rotation of the mantle block. Characteristics of the Primorye zone of deep-focus seismicity at the Russia–China boundary are stated. 13 earthquakes with Ì 6.0 have been registered in the zone at a depth of 300–500 km since 1973, which is at least twice as many as compared with the number of large deep-focus earthquakes elsewhere in the Sea of Japan – Sea of Okhotsk transition zone. The unique genesis of the Primorye seismic zone is related to additional compression in the seismofocal area caused by creeping of the Anyui mantle block onto the subduction zone during its rotation. Geodynamic implications of seismotectonic analysis are examined, and the necessity of division of the Amur plate into three geodynamically independent lithosphere blocks is substantiated. Key words: mantle structure, seismic cycles, earthquake migration, deep-focus seismicity, tectonic extrusion, Russian Far East. A.T. Sorokina, A.P. Sorokin, M.A. Serov, A.A. Popov Fault-block structures of the eastern margin of the Amur lithosphere plate, their seismicity and fluid regime The results of the many years’ studies of neotectonic processes and the related events such as degassing of the Earth’s interior, fluid discharge, and high seismicity within the boundary territory of the Upper and Middle Amur in the zone of interaction of the Amur and the Okhotsk lithosphere plate are summarized. Blocks are distinguished and their geodynamic features, their relations with seismic events are considered, and also the period of their activity and tranquility are established. Based on heliometric and atmochemical investigations within the Zeya-Bureya basin, the zones of higher permeability are recognized. The results of the many years’ observations of fluid dynamics at the Konstantinovka mineral water deposit are offered, and the relation of water-dissolved helium variations and the change of the deformed state of the blocks that are at a distance of 220 km from the station of regime observations are stated. Key words: neotectonics, seismicity, degassing, helium, fluid regime, Amur lithosphere plate, Zeya-Bureya basin, fault-block structures. V.P. Simanenko, S.V. Rasskazov, T.A. Yasnygina, L.F. Simanenko, A.A. Chashchin Cretaceous complexes of the frontal zone of the Moneron-Samarga island arc: geochemical evidence of basalts from the deep hole on Moneron Island (Sea of Japan Variations of petrogenic oxides and microelements determined by the ICP-MS method have been studied in the Cretaceous rocks outstripped by a deep hole on Moneron Island in the depth interval 1253-4011 m. The volcanogenic section holds two complexes: Early Cretaceous and Late Cretaceous. The rocks of the Early Cretaceous complex occur below 1500 m. Chemically, they belong to low-potassium island arc tholeiites, and microelement distribution suggests their formation in a suprasubduction mantle wedge under the influence of water fluids, which arrived first from the subducting sediments and oceanic plate during dehydration of the subducted sedimentary rocks and oceanic basalts; and at the final stages, mainly from basalts of the oceanic plate. The Early Cretaceous basalts from the hole belong to the frontal part of the Moneron-Samarga island-arc system. The volcanic rocks of the Late Cretaceous complex occur above 1500 m. They are also a subsubduction geodynamic type in the structure of the East Sikhote-Alin marginal-continental volcanic belt that formed after accretion of the Moneron-Samarga island-arc system to the Asian continent. The island-arc section of the Moneron hole holds dikes of andesite basalts, which geochemically are comparable with the Early-Middle Miocene volcanic rocks of SW Sakhalin. Key words: Cretaceous, Cenozoic, volcanic rocks, basalts, diabases, microelements, Sea of Japan. B.I. Pavlyutkin, I.Yu. Chekryzhov, T.I. Petrenko Voznovskaya suite as an image of the Early Oligocene stage in the geologic history of the East Sikhote-Alin New evidence is offered of the Voznovskaya suite, one of the key Tertiary stratons of the East Sikhote-Alin. The analysis of the corresponding macro- and microflora allowed a conclusion on the invalidity of the decision (Resheniya…, 1994 (Decisions…, 1994)) to transpose the suite to the Miocene stratigraphic level. Its Early Oligocene age has been justified. It is shown that the rocks making up the suite formed in conditions of a subpond lake. The paper gives the ecological characteristics of the Voznovskaya taphoflora, testifying to its mountain ecotype and, as a result, to the antiquity of the Sikhote-Alin mountain system. Correlation of the Voznovskaya suite with other similar-age stratons of the region has been accomplished. Key words: stratigraphy, Early Oligocene, Voznovskaya suite, fossil florae, Sikhote-Alin. V.G. Khomich, N.G. Boriskina Fundamental geologic-genetic types of native gold deposits of the Transbaikal region and the Russian Far East In the territory of the Transbaikal region and the Russian Far East, tens of gold deposits of different genetic classes (endogenous and exogenous), groups, and types have been recognized and evaluated to a various degree. They occur within cratons, orogenic belts and magmatic arcs. The formation of precious metal mineralization of the region is conditioned by different type ore-genetic systems, which generated magmatogenic-hydrothermal, metamorphogenic-hydrothermal, hydrothermal-sedimentary-metamorphogenic and hydrogenic deposits. The integration of geologic-genetic and commercial types of gold deposits is the basis of such conceptions of metallogenic analysis as ore formation, and ore-formation and geologic-commercial types of mineralization. Lately, the researchers of gold deposits, particularly large ones, have come to a conclusion of their polygenic and polychromic character, which is supported by a rather long, up to hundreds of million years, time interval of conjugate development of processes of ore formation, sedimentation, metamorphism, and magmatism of different geodynamic nature. Key words: gold, deposits, new types of mineralization, Transbaikal region, Far East. Anna Al. Lotina Gold-bismuth-telluric mineralization at the Bolotistoye placer field (North-Western Sikhote-Alin) The results of investigation of bismuth-telluric mineralization at the Bolotistoye gold-bearing ore occurrence (the Khor River basin, Khabarovsk Territory) are offered. Extracted and studied minerals are tellurobismuthite (Bi2Te3), tetradymite (Bi2Te2S), tsumoite (BiTe), protojoseite (Bi2Te4S), and native bismuth. Major elements of admixture of these minerals are lead and selenium. Two mineral associations are distinguished: 1 – early quartz-arsenide-sulphide related to bismuth-telluric minerals associated with Eocene gabbro-diorite, diabase and quartz diorites; 2 – late quartz-tourmaline-gold-tetradymite-tellurobismuthite association superposed on the Eocene dacite bodies, dikes of medium and acidic composition and Cretaceous sedimentary beds, which became the major source for commercial gold placers. It is assumed that there are two types of mineralization of hypabyssal level. Key words: gold, bismuth, tellur, mineralization, Sikhote-Alin.N N.A. Kharitonova, G.A. Chelnokov, Ye.A. Vakh, V.A. Goryachev Geochemistry of Nizhniye Luzhki carbonaceous mineral deposit (Primorye) Integrated investigation of the Nizhniye Luzhki spa (Sikhote-Alin, Primorye) made it possible to recognize the main factors controlling the gas-geochemical feature of this spa. It is shown that the spa is located in the complicated geologic and hydrogeologic conditions and spreads over a small area controlled by the inflow of carbon dioxide into water. It is indicated that the waters are of a meteoric origin, and the alimentation of the mineral water aquifer is mainly controlled by the bedrock filtration parameters, and the mineral water circulation period exceeds 50 years. The chemical composition of the waters depends on the rate and degree of water-bedrock-carbon dioxide interaction. The calculations of minerals saturation indexes indicate that the spa is at an early stage of calcium saturation and are undersaturated with both carbonates and alumosilicates. Ca, Mg, Na and Fe are most mobile elements in these geochemical conditions, which testified to the low degree of the water-bearing rocks weathering. Key words: hydrogeology, mineralization, water-rock interaction, geochemistry, Primorye. |