Structure and composition of the sedimentary cover in the Knipovich Rift valley and Molloy Deep (Norwegian-Greenland basin)
Autor: | S. I. Stupin, E. P. Radionova, G. N. Aleksandrova, A. A. Peive, V. N. Efimov, S. Yu. Sokolov, N. P. Chamov, V. V. Kostyleva, M. E. Bylinskaya |
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Rok vydání: | 2010 |
Předmět: | |
Zdroj: | Lithology and Mineral Resources. 45:532-554 |
ISSN: | 1608-3229 0024-4902 |
Popis: | The multidisciplinary approach is used to analyze the structure of the sedimentary cover in the northern Knipovich Rift valley, Molloy Fracture Zone and synonymous basin, Svyatogor and Hovgard rises, Gorynych Hills, Litvin and Pogrebitskii seamounts, and western slope of the Spitsbergen Archipelago studied in Cruise 24 of the R/V Akademik Nikolaj Strakhov. Materials of the bathymetric survey with multibeam echo sounder, as well as continuous seismic and vertical acoustic profiling, revealed two main (NNW- and NNE-trending) systems of fractures in the neotectonic structure of the region. It was established that a system of NNE-oriented fractures, linear zones of the dominant development of keyboard deformations included, is consistent with the strike of magnetic anomalies reconstructed for this region. Tectonic aspects of the Knipovich Rift and prospects of its further development are considered. Based on the wave field pattern of continuous seismic profiling (CSP) records, four seismocomplexes indicating contrasting sedimentation settings and intense tectonic processes at different formation stages of the northern Norwegian-Greenland Sea are conditionally defined in the sedimentary cover of the study region. It was established the Molloy Fracture Zone is responsible for a system of horizontal reflectors of acoustically transparent structureless light spots (“blankings”) in the upper well-stratified part of the sedimentary section, which are characteristic of areas with ascending pore fluids. The micropaleontological study (palynomorphs of higher plants, dinocysts, planktonic foraminifers, and diatoms) revealed the presence of Miocene assemblages in sediments. Benthic foraminifers include late Paleocene-middle Eocene assemblages. The composition of rock-forming components demonstrates a directed succession of mineral-terrigenous associations from the feldspar-quartz type to mesomictic quartz-graywacke type. |
Databáze: | OpenAIRE |
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