排序方式: 共有6条查询结果,搜索用时 15 毫秒
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Henning Lorenz David G. Gee Evgeny Korago Galina Kovaleva William C. McClelland Jane A. Gilotti Dirk Frei 《地学学报》2013,25(6):496-503
The Novaya Zemlya fold‐and‐thrust‐belt is the northern continuation of the late Palaeozoic Uralide Orogen. Little is known about its deeper structure and the basement history of the adjacent Barents and Kara shelves. Based on geological evidence and detrital zircon analysis of 28 samples from the northeastern and stratigraphically deepest part of the archipelago, we demonstrate that Cambro‐Ordovician turbidite‐dominated deposition was almost exclusively sourced from rocks consolidated during the Timanian orogeny (Timanian basement). A profound change in provenance occurred near the end of the Ordovician. Over 90% of the zircons from Silurian and about 80% from Devonian strata have ages characteristic of the Sveconorwegian Orogen, implying uplift of these rocks in the vicinity of Novaya Zemlya. The presence of Sveconorwegian and Grenvillian rocks in the high Arctic suggests revision of recent reconstructions of the Rodinia supercontinent, its break‐up and subsequent Caledonian orogeny. 相似文献
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N.L. Dobretsov V.A. Vernikovsky Yu.V. Karyakin E.A. Korago V.A. Simonov 《Russian Geology and Geophysics》2013,54(8):874-887
The patterns and history of Mesozoic–Cenozoic plume magmatism in the Arctic is considered in relation with suprasubduction volcanism and geodynamic events. The Mesozoic–Cenozoic magmatic history of the area includes seven stages, distinguished by correlation of ages and compositions of volcanics associated with mid-ocean rifting, plumes, and subduction; three of seven stages correspond to global events at 230–200 Ma, 130–120 Ma, and 40–30 Ma. The reported study supports the inferred inverse correlation between plate velocities and amount of subduction-related volcanism. The gained knowledge is used for paleotectonic reconstructions in the Arctic. 相似文献
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Korago E. A. Kovaleva G. N. Schekoldin R. A. Il’in V. F. Gusev E. A. Krylov A. A. Gorbunov D. A. 《Geotectonics》2022,56(2):123-156
Geotectonics - Our study considers the structure and tectonics of the Novaya Zemlya archipelago, located in the west Russian Arctic and part of the Eurasian Arctic: (i) the age of the Pre-Paleozoic... 相似文献
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N. M. Sushchevskaya E. A. Korago B. V. Belyatsky A. N. Sirotkin 《Geochemistry International》2009,47(10):966-978
Petrological and geochemical data obtained on Neogene magmatism restricted to a deep fault in Andree Land at Spitsbergen Island,
which was related to the overall restyling of the Arctic territory at 25–20 Ma, indicate that the derivation of the Neogene
magmas was significantly affected by the continental pyroxenite mantle. The Neogene basalts are noted for a radiogenic isotopic
composition of Pb (207Pb/204Pb= 15.5–15.55, 206Pb/204Pb = 18.4–18.6, 208Pb/204 Pb = 38.4–38.6) and Sr(87Sr/86Sr = 0.7038–0.7048) at low 143Nd/144Nd = 0.5129. Melts of this type are the extremely enriched end member of the isotopic mixing of a depleted and enriched sources
and determine a geochemical trend that passes through the compositions of alkaline magmas from Quaternary volcanoes at Spitsbergen
and weakly enriched tholeiites of the Knipovich Ridge, which started to develop simultaneously with the onset of Neogene magmatism
in the western part of Spitsbergen. The composition of the liquidus olivine (which is rich in NiO) indicates that melting
occurred in the olivine-free mantle. Our data thus testify that a significant role in the genesis of the Neogene magmas was
played by continental pyroxenite mantle. 相似文献
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