Volume 29, 6, 2010 |
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I.V. Buchko, A.A. Sorokin. First evidence of noble metal geochemistry of rocks of the gabbro-anorthosite massifs, Kalar group 3 E.G. Konnikov, V.M. Chubarov, V.A. Poletaev, P.G. Bukhtiyarov. New data on the structure and geochemistry of the Dukuk gabbro-norite-cortlandite massif of Kamchatka 13 V.I. Rozhdestvina, A.P. Sorokin. The first finds of native palladium, platinum, gold and silver in the brown coals of the Yerkovetskoye deposit (Upper Priamurye) 26 Yu.F. Manilov. Features of the deep structure of the Argun-Mamynskiy massif’s south-eastern part (from geophysical evidence) 39 A.V. Kudymov. Cenozoic stress fields in the Kiselevka fault area, Lower Priamurye 49 V.S. Markevich, E.V. Bugdaeva, Yu.L. Bolotsky. Palynoflora of Gilchin and Dimskoe dinosaur localities (Zeya-Bureya Basin, Russian Far East) 57 V.V. Kulakov, L.M. Kondratyeva, Ye.M. Golubeva. Geologic and biogeochemical prerequisites of Fe and Mn increased content in the Amur River water 66 V.P. Semakin, A.V. Kochergin. Neotectonics of the Deryugin Basin Region (Sea of Okhotsk) (A.N. Derkachev, I.V. Utkin. Discussion) 77 L.B. Khershberg, A.A. Ryazantsev , Ye.V. Mikhailik, O.V. Chudaev. Development of stratigraphic base for 1:200 000-scale geologic survey of shelf areas of the Russian Far East seas 90 E.V. Sasorova , M.Yu. Andreeva. Deep distribution of the hypocenters of earthquakes of Kuril Region 107 Brief Communications S.V. Zyabrev, M.V. Matrynyuk, Ye.K. Shevelev. The age of limestone from the south-western fragment of the Kiselevka-Manominskiy accretionary complex, Russian Far East (based on radiolarians) 116 A.S. Astakhov, A.A. Bosin, A.N. Kolesnik, D.A. Korshunov, K. Crane, Ye.A. Logvina. Geologic investigations in the Chukchi Sea and the adjacent regions of the Arctic Ocean, RUSALCA-2009 expeditions 119 Chronicles V.G. Bykov, A.N. Didenko, T.V. Merkulova. The problems of seismicity and present-day geodynamics of the Far East and East Siberia 126 Jubilees V.G. Gonevchuk (to the 70-th anniversary) 133 Index of papers published in 2010 134 AI.V. Buchko, A.A. Sorokin First evidence of noble metal geochemistry of rocks of the gabbro-anorthosite massifs, Kalar group The paper characterizes geochemical features of noble metal impregnated sulfide and titanium-magnetite mineralization in the Kalar rocks of autonomous-type gabbro-anorthosite massifs. The investigations suggest at least two stages of formation of this mineralization. The first stage is related to gabbro-anorthosites proper, and it may be promising with respect to low-sulfide platinum-metal and also platinum-bearing titanium-magnetite mineralization, whereas the second type is linked to ultrabasite bodies, which are associated with copper-nickel or chromite mineralization with accompanying platinoids. The low-sulfide horizons in gabbro-anorthorthosites and copper-nickel mineralization in dunites-pyroxenites are characterized by Pd predominance over Pt, and chromite-bearing rocks and titanium-magnetite ores are noted for Pt predominance over Pd. Key words: geochemistry, noble metals, mineralization, gabbro-anorthosite massifs, Stanovoy superterrane. E.G. Konnikov, V.M. Chubarov, V.A. Poletaev, P.G. Bukhtiyarov New data on the structure and geochemistry of the Dukuk gabbro-norite-cortlandite massif of Kamchatka The Dukuk intrusive massif is considered petrotypical for the gabbro-norite-cortlandite complex of Kamchatka. This paper offers new ideas concerning the Dukuk massif’s inner structure and relations between mafic and ultramafic rocks within it, and also the results of investigation of trace element distribution in the massif shedding light on the origin of the initial melt of the norite-cortlandite complex and on the prospects of detection of commercial sulfide mineralization in it. Besides, new evidence of U-Pb age determination of the Dukut intrusion is presented allowing us to specify the time of formation of both the intrusion and the complex as a whole. Key words: layered intrusions, geochemistry, nickel content, absolute age, Kamchatka. V.I. Rozhdestvina, A.P. Sorokin The first finds of native palladium, platinum, gold and silver in the brown coals of the Yerkovetskoye deposit (Upper Priamurye) Minerals of the native elements Pd, Pt, Au, Ag and Au-Ag solid solutions, and also Pb, Zn, Cu, Bi, Fe, Cr, Ni, W, Al, their intermetallides, and a number of other ore minerals have been detected in the coals of the Yerkovetskoye brown coal deposit. The structural organization of the noble metal grains, and also of most other minerals found in brown coals suggests their authigenic paragenesis. The arrival of noble metals in the brown coals is possible in an ionic form from surface and underground waters as mineral particles transported by wind from goldfields. Key words: platinum, palladium, gold, silver, brown coals, diagenesis. Yu.F. Manilov Features of the deep structure of the Argun-Mamynskiy massif’s south-eastern part (from geophysical evidence) Comprehensive interpretation of the geologic-geophysical information resulted in the geologic-structural map of the SE Argun-Mamynskiy massif overlain by Mesozoic-Cenozoic sedimentary deposits. The boundaries of the main elements of the study territory have been outlined; and systems of rupture dislocations with a ring structure at their junction have been distinguished. The distinguished structure has a complex block pattern of the Earth’s crust. The presence of different-age magmatic assemblages within it makes it possible to identify this structure as a volcanic-plutonic dome structure. The relation of the dome with the deep inhomogeneities of the lithosphere has been defined, and its metallogenic zoning has been recognized. Key words: geologic-geophysical analysis, geologic-structural map, intrusive-domal structure, metallogenic zoning, Argun-Mamynskiy massif. A.V. Kudymov Cenozoic stress fields in the Kiselevka fault area, Lower Priamurye The study of sliding tectonic surfaces and striae, and also of strike-slip echelons of quartz streaks in the Kiselevka fault zone helped reconstruction of four groups of stress fields of a wide age range – from Paleocene to Recent. Meridional compression and latitudinal extension of the earliest stress field conditioned left-lateral displacement along the Kiselevka fault. The fault activation in that period was accompanied with final-phase magmatite formation in the East Sikhote-Alin volcano-plutonic belt. The subsequent stress field, the other way, of sublatitudinal compression and submeridional extension, changed the fault kinematics to right-lateral strike-slip. The origin and development of the Udyl intermountain depression is linked to these deformations. Upthrow deformations complicated the structure of the Udyl depression, and normal fault deformations resulted in the formation of the depression of Lake Udyl proper and bays along the Amur River left bank. Key words: stress fields, sliding surfaces and striae, Cenozoic, Kiselevka fault, Kiselevka terrane, Lake Udyl, Lower Priamurye. V.S. Markevich, E.V. Bugdaeva, Yu.L. Bolotsky Palynoflora of Gilchin and Dimskoe dinosaur localities (Zeya-Bureya Basin, Russian Far East) The palynological assemblages from the Gilchin and Dimskoye dinosaur localities of the Zeya-Bureya Basin were studied. The first assemblage is characterized by the high content of pteridophytes spores is characteristic of the first assemblage, further in the decrease abundance - by tricolpate pollen, bisaccate pollen of Pinaceae, Ginkgocycadophytus, pollen of Òaxodiaceae, Ñupressaceae and Òaxaceae (ÒÑÒ), Ulmoideipites è «unica»-type pollen. The palynological assemblage from theDimskoye locality is dominated by pteridophytes spores, next in abundance - by platanaceous and ulmaceous pollen, common to riparian plant communities. The share of bisaccate pollen is important, TCT pollen and Ginkgocycadophytus is insignificant. Triporate and "unica"-type pollen is minor. The bone-bearing burials of the Gilchin and Dimskoye dinosaur localities formed under conditions of vast swampy alluvial valleys covered by ferns and taxodialeans. Platanaceous and ulmaceous pollen can confirm existence of valley river light forests. Also Ulmaceae pollen can evidence in favor of the abruptly changed environment conditions, perhaps, inconstant water supply. A small number of bisaccate pollen may be conditioned by a far distance to the slope frame of the basin. Key words: palynology, stratigraphy, Late Cretaceous, Maastrichtian, Tsagayan Formation, dinosaurs, Zeya-Bureya basin. V.V. Kulakov, L.M. Kondratyeva, Ye.M. Golubeva Geologic and biogeochemical prerequisites of Fe and Mn increased content in the Amur River water The paper examines the role of natural and anthropogenic factors in the seasonal dynamics of Fe and Mn in the Amur River water. The contribution of biogeochemical processes in Fe and Mn ion migration in the contact zones “water – river bed” and “underground waters – surface waters” is grounded. The causes of an anomalously high Mn concentration in the Amur River water at the beginning of 2005 freezing after the technogeneous accident in China are discussed. Key words: surface and underground waters, Fe, Mn, biogeochemical barrier, Amur River basin. V.P. Semakin, A.V. Kochergin Neotectonics of the Deryugin Basin Region (Sea of Okhotsk) A structural-neotectonic scheme and a scheme of basic neotectonic structural elements were compiled based on the sea bottom «summit» surface. The comparison of these schemes with paleogeographic schemes of lithophysical complexes of four time intervals (K2 –1-2, 3 – N11, N11-2 and N13 – N2) established that beginning from the end of the Late Cretaceous to the Late Pliocene there were either continental conditions or conditions of a relatively shallow sea in the most part of the territory, and only in the western part of the region there was forming a relatively deep-sea trough, whose axial line was located farther westward from the Deryugin neotectonic basin and the Staritsky trough. In the Late Pliocene shelf depths seemed to be in the territory of the deep-sea paleotrough (3 – N22 ) and the Deryugin basin when sedimentation continued. Paleogeography of the region from the late Pliocene to the Late Rissian (Tazovian) glaciation (6 isotopic-oxygen stages – 6 IOS) is not clarified. The most complete section of Quaternary deposits is outstripped by column LV 28-34-2, where 6 horizons were distinguished, of which Nos 1, 3 and 5 correspond to warm time intervals (IOS) and horizons 2, 4 and 6 correspond to cold time intervals. Sea depths in the periods of cold IOS (horizons 2, 4, 6) were shallower than in the warm IOS (horizons 1, 3, 5), which is related to uplifts and subsidences of sea bottom, respectively. During the Late Pleistocene-Holocene period (~ 17 000 years) the Deryugin basin was subsiding at an average rate of 8 cm/year; and the near-arch part of the Institute of Oceanology Rise, at a rate of 3 cm/year. Key words: summit surface, neotectonics, newest structural form, flexure, tectonic scarp, uplift, trough, Derygin Basin, Sea of Okhotsk. L.B. Khershberg, A.A. Ryazantsev, Ye.V. Mikhailik, O.V. Chudaev Development of stratigraphic base for 1:200 000-scale geologic survey of shelf areas of the Russian Far East seas For the first time the geological survey expedition of the Primorye Territorial Geologic Administration has mapped 7 regions (4 in the Sea of Japan, and 3 in the Sea of Okhotsk). Extensive actual material has been accumulated on these regions, which made it possible to construct reference sections of the geologic structure of sedimentary cover, and also to develop working stratigraphic charts of Quaternary deposits. The mapping of shelf regions is based on the lithostratigraphic principle of division of sections of Quaternary deposits, which makes it possible to distinguish in the sedimentary cover lithologically isolated units corresponding to certain stages of transgressive-regressive activity of the sea and stages of placer formation. Key words: geologic survey, shelf, Quaternary deposits, Sea of Japan, Sea of Okhotsk. Ye.V. Sasorova , M.Yu. Andreeva Deep distribution of the hypocenters of earthquakes of the Kuril region This work is aimed at a comparative analysis of earthquake distribution by depth and magnitude in the four study subregions of the Kuil Islands and numerical determination of the Hopt value for these subregions. The Hopt value is the depth boundary which divides seismic events in every study subregion into two non-overlapping subsets. The seismic events of the first subset are distributed non-uniformly during the year, while the distribution of seismic events of the second subset is uniform. The analysis shows that the boundary position between these two subsets depends on the character of hypocenter distribution over the depth and on the magnitude values. The optimal threshold value of the depth calculated by statistical method varies from 40 to 80 km for the Southern, Middle Kuriles and Hokkaido Island and from 60 to 100 km for the Northern Kuriles. A comparison was made of the statistical analysis results with the earthquake distribution over depth according to the basic Kuril catalog. Key words: earthquakes, depth, energy, magnitude, Kuril Islands, Hokkaido Island. |