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Òîì 33, 1, 2014 |
| Y.D Zakharov, A.S. Biakov, M. Horacek.
Global correlation of the basal Triassic beds (in the light
of the first carbon-isotopic evidence on the
Permian-Triassic boundary in Siberia) 3 A.N. Didenko, À.I. Khanchuk, À.I. Tikhomirova, I.P. Voinova. The eastern segment of the Kiselevka-Manoma terrane (northern Sikhote-Alin): paleomagnetism and geodynamic implications 20 À.V. Grebennikov, V.K. Popov. Petrogeochemical aspects of the Late Cretaceous and Paleogene ignimbrite volcanism of East Sikhote-Alin 41 G.A. Valuy, E.Yu. Moskalenko. Evolution of Nd-Sr ratios through formation of the Cretaceous-Paleogene granitoids of Primorye 58 G.M. Vovna, M.A. Mishkin, A.M. Lennikov, R.A. Oktyabrsky, V.F. Polin, Z.G. Badredinov, T.A. Yasnygina. Geochemistry and original nature of metamorphic rocks of the Batomgskaya granite-greenstone area (Aldan Shield) 66 T.K. Pinegina, A.I. Kozhurin, V.V. Ponomareva. Active tectonics and geomorphology of the Kamchatka Bay coast, Kamchatka 75 A.V. Romanova, M.V. Cherepanova, S.A. Gorbarenko. Planktonic foraminifera as paleoenvironmental proxies of Upper Quaternary sedimentation in the Okhotsk Sea 89 I.U. Rasskazov, N.I. Grehnev, T.N. Alexandrova. Anthropogenic deposits inside dumps of ore-dressing and processing enterprises of the Far East region 102 Chronicles Î.V. Chudaev, G.À. Chelnokov. The 14th International Symposium "Interaction water-rock", 9–14 June, 2013, Avigon, France 115 À.N. Didenko, Yu.F. Manilov. Tectonics, deep structure and minerageny of East Asia: The VIIIth Academician Yu.A. Kosygin Readings 118 Notes fot Contributors 122 Y.D Zakharov, A.S. Biakov, M. Horacek Global correlation of the basal Triassic beds (in the light of the first carbon-isotopic evidence on the Permian-Triassic boundary in north-east Asia) The paper is devoted to global correlation of the marine Permian-Triassic boundary sequences. Partly published and original data on δ13Corg è δ13Ccarb values on the Suol section (Setorym River, South Verkhoyansk area) were used in this investigation. Six carbon-isotope intervals have been determined in the section, which are easily recognized in carbon-isotope curves from the basic sections of Eurasia and North America, including paleontologically well characterised sections of Central Iran, Kashmir, and South China. This permits to assume the P-T boundary position in the Suol section closed to the minimum carbon-isotope interval IV. In the light of the new data the upper part of the Changhsingian stage of the Upper Permian in Siberia is offered to be considered in the extent of Otoceras concavum range zone, but the Induan lower substage of the Lower Triassic – in the volume of the Tompophiceras pascoei and Wordieoceras decipiens zones. On the basis of a new interpretation, the Otoceras concavum zone in the Verkhoyansk area corresponds most likely to the late Changhsingian Hypophiceras triviale zone in Greenland. The carbon-isotope intervals II, III, IV and V, recognised in the P-T boundary beds of the Verkhoyansk area and traced in some basic sections of Eurasia, reflect apparently some intensification of volcanic activityó at the beginning of late Chanhsingian and the first massive eruptive phases of the Siberian Traps at the end of the Changhsingian and the beginning of the Induan. New data are evidences of possible survival of ammonoid Otoceratoidea on the specific level after the Late Permian mass-extinction of organisms. Key words: Upper Permian, Lower Triassic, molluscs, carbon isotopes, South Verkhoyansk area, NE Asia, global correlation. A.N. Didenko, À.I. Khanchuk, À.I. Tikhomirova, I.P. Voinova The eastern segment of the Kiselevka-Manoma terrane (northern Sikhote-Alin): paleomagnetism and geodynamic implications The following conclusions have been made based on the results of the comprehensive geologic-geophysical research on lower Cretaceous volcanosedimentary rocks of the Kiselevka block of the Kiselevka-Manoma tectonostratigraphic terrane: 1) the composition of volcanogenic rocks and the lithology of sediments of the Kiselevka block are indicative of their formation in the within-plate oceanic setting; petrological and geochemical characteristics of the studied volcanic rocks are similar to those of volcanic rocks of the Hawaiian hot spot; 2) the characteristic component of the natural remanent magnetisation of the volcanosedimentary rock complex of the Kiselvka block was isolated, which yielded a positive fold test and is similarly aged as the rocks. According to the direction of the characteristic component the paleolatitude at which rocks formed (18 ± 5° N) was determined as well as coordinates of the Kiselevka block paleomagnetic pole (Plat = 18.6°, Plong = 222.4°, dp = 5.2, dm = 9.1°); 3) newly obtained and published data allowed kinematic reconstructions to be made under which the Kiselevka block: 1 – in the Valanginian-Albian was northwesterly moving on the Izanagi plate at 15-20 cm/year having covered a distance over 5,000 km to the Eurasia margin (the Korean peninsula); 2 – in the Albian-Campanian was northerly moving as a fragment of the Kiselevka-Manoma accretionary prism along the Eurasia transform margin at 4-5 cm/year to its present-day position where it had become part of the continental plate Key words: paleomagnetism, geochemistry, geodynamics, Kiselevka-Manoma terrane, Sikhote-Alin. A.V. Grebennikov, V.K. Popov Petrogeochemical aspects of the Late Cretaceous and Paleogene ignimbrite volcanism of East Sikhote-Alin Features of chemical and minor-element composition of the Late Cretaceous and Early Paleogene ignimbrite complexes in the Eastern Sikhote-Alin are discussed. Linear structure of the East Sikhote-Alin volcanic belt is predominantly composed of the Turonian-Campanian volcanic formations of the Primorsky complex represented by crystal-rich rhyolitic, rhyodacitic and dacitic S-type plateau-ignimbrites which are the results of fissure (areal) eruptions of acid magmas. The Maastrichtian–Paleocene volcanic rocks are space-independent from the volcanic belt; they fill isolated volcanic caldera and depression structures. That period is characterized by bimodal volcanism. The Samarginsky, Dorofeevsky and Severyansky volcanic complexes are made up of lavas and pyroclastic rocks of basalt-andesite-dacite composition, the Levosobolevsky and Siyanovsky complexes consist of rhyolitic and dacitic tuffs and ignimbrites. Petrogeochemically, persilicic igneous rocks of that period are still close to the S-type plateau-ignimbrites of the Primorsky complex. The Paleocene-Early Eocene silicic extrusive rocks of the Bogopolsky complex present both S- and A-type dacitic and rhyolitic tuffs and ignimbrites in collapse caldera. The eruption of ferrous A-type hyaloignimbrites occurred at the terminated stages of the Bogopolsky complex volcanism. Magmatic rocks of the period have clearly defined mineralogical and geochemical features of the interaction between crustal magmas and the enriched material of the upper mantle. Revealed differences in mineralogical and geochemical composition of ignimbrite complexes are explained as indicators of changes in geodynamic regime of the Asia active continental margin at the Mesozoic-Cenozoic boundary. Key words: plateau-ignimbrites, hyaloignimbrites, S- and A-type granitoids, geotectonic settings of volcanism manifestations, Sikhote-Alin. G.A.
Valuy, E.Yu. Moskalenko
Evolution of Nd-Sr ratios through formation of the Cretaceous-Paleogene granitoids of Primorye Nd and Sr isotopes were first studied in the Late Cretaceous-Paleogene magnetite granitoids of the Primorskaya series (Oprichnensky, Dal’negorsky, Brinerovsky, Vladimirsky, Ol’ginsky, and Valentinovsky massifs of the East-Sikhote-Alin volcano-plutonic belt, in the Early Cretaceous ilmenite granitoids of the Tatibinskaya series of the Central-Sikhote-Alin plutonic belt – Uspensky and Livadiisky massifs, as well in the Eocene alkaline granites of Orlov Cape. It was established that the granitoids of the ESAPB eastern part are characterized by lower negative and even positive values of εNd and by lower initial ratios of 87Sr/86Sr (0.704-0.706) as a whole in comparison with the granitoids of the belt western part (Dal’negorsk adamellites and Nikolaevsk gabbro) and the Early Cretaceous Uspensk granitoids of the CSAPB (0.706–0.707 and εNd = -3.14 to -3.29) whose isotopic characteristics testifies to more ancient model ages and a greater degree of contamination of the initial melts through their formation. We have revealed a synchronous increase of 87Rb/86Sr and 87Sr/86Sr from early basic to late acid phases and from near-contact to central parts within a single massif, whereas in the rock-autolith pairs the 87Rb/86Sr ratio decreases and 87Sr/86Sr ratio increases. As a whole, the obtained Sm-Nd and Rb-Sr isotope characteristics of the Cretaceous-Paleogene granitoids of Primorye point to the fact that they originated from the melts derived from the rocks with the mantle parameters and short-term crustal history, which have not undergone recycling, that characterizes the granite formation in the continent-ocean transition zone. Key words: Nd, Sr isotopes, granitoids, Cretaceous, Paleogene, Primorye. G.M.
Vovna, M.A. Mishkin, A.M. Lennikov, R.A. Oktyabrsky,
V.F. Polin, Z.G. Badredinov, T.A. Yasnygina
Geochemistry and original nature of metamorphic rocks of the Batomgskaya granite-greenstone area (Aldan Shield) In the composition of the Early Proterozoic metamorphic complex of the Batomgskaya granite-greenstone area two petrochemical series of volcanites are distinguished among the magmatic protoliths: calc-alkali and comatiite-tholeiite series. Metavolcanites of the calc-alkali series are metabasalts, metaandesites, metadacites, and metarhyolites. The spectrum distribution of trace elements in acid metavolcanites demonstrates a similar topology with that of the Archean grey gneisses of the platform basement that may testify to a close petrological mechanism of their protolith formation. Comatiitic and tholeiitic basalts have been recognized among the metavolcanites of the comatiite-tholeiite series. Their chemistry agrees with the model of the fractionation of high-magnesium basalts in the interstitial chambers at low pressures. Nb, Y, Zr content in metatholeiites indicates that their original melts have a plume source. Key words: granite-greenstone area, geochemistry, metabasalts, metaandesites, metadacites, metarhyolites, Aldan Shield. T.K. Pinegina, A.I. Kozhurin, V.V. Ponomareva Active tectonics and geomorphology of the Kamchatka Bay coast, Kamchatka The Kamchatka Bay is the northernmost bay at the Pacific Kamchatka coast. It is located above the junction of the Kamchatka segment of the Pacific subduction zone and right-lateral Western Aleutian transform fault. Combination of the subduction and collision processes in this region results in the unique set of the tectonic agents that influence on its geological and geomorphological evolution. The Kamchatka River mouth area is located at the northern coast of the Kamchatka Bay. Modern Kamchatka river valley, its estuary, and 30 km long and up to 5 km wide marine accumulative terrace have been formed in this area during the Holocene. A vast area in the rear part of the terrace and in the Stolbovsky depression is now occupied by the peats formed over lacustrine, lagoon and fluvial deposits. These accumulative landforms preserve both the traces of tsunami and vertical coseismic deformations associated with the largest subduction-related earthquakes, and of reverse and strike-slip faulting associated with the collision. The data acquired show that recurrence interval of tsunami in the Kamchatka Bay averages around 300 years. It amounts to the first thousand years for individual collision-related faults, with M of fault-generated earthquakes reaching 7-7.5. For the entire area the recurrence interval of strong crustal earthquakes associated with motions along the faults may be the first few hundred years - an amount comparable with that for subduction earthquakes. Key words: subduction, arc-arc collision, active fault, tsunami, Holocene, Kamchatka River downstream area, marine terrace, Kamchatka Bay. A.V. Romanova, M.V. Cherepanova, S.A. Gorbarenko Planktonic foraminifera as paleoenvironmental proxies of Upper Quaternary sedimentation in the Okhotsk Sea Planktonic foraminifera were studied from Pleistocene-Holocene sediment core 936 in the Central Okhotsk Sea. Five complexes of planktonic foraminifera were determined corresponding to five marine isotope stages (MIS) that have been previously established for this core. The peculiar features of paleoassemblages formed under specific paleogeographic conditions were identified. A sharp increase in foraminifera abundance is observed in ‘warm” MIS 1. The main criterion for interglacial MIS 3 is fluctuation of Globigerina bulloides and Globigerina quinqueloba frequency. The highest abundances of Neogloboquadrina pachyderma sin are established for «cold» MIS 2 and MIS 4. Key words: planktonic foraminifera, Late Pleistocene, Holocene, the Okhotsk Sea. I.U. Rasskazov, N.I. Grehnev, T.N. Alexandrova Anthropogenic deposits inside dumps of ore-dressing and processing enterprises of the Far East region Economic and environmental aspects of mineral waste material of mining in the southern part of the Far Eastern region are given in the article. Reject concentrated in huge tailing dumps are considered like large complex anthropogenic deposits containing considerable reserves of copper, tin, arsenic, lead, zinc, rare and noble metals. It was shown that anthropogenic deposits are basic and long-term sources of chemical pollution of environment, especially ones of surface watercourses and industrial horizons of underground water. Key words: anthropogenic deposits, rare metals, mineral waste material, sour under-dump water, the Far East of Russia. |