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| Gernigon, Laurent; Lucazeau, Francis; Brigaud, Frederic; Ringenbach, Jean-claude; Planke, Sverre; Le Gall, Bernard. |
| High P-wave velocities (7.1-7.8 km/s) lower crustal bodies (LCBs) imaged along volcanic margins are commonly interpreted as plume and break-up-related thick mafic underplating. This interpretation is partly challenged in this paper based on new seismic observations and modelling of the outer Voring Basin (Norway). An exceptional strong amplitude reflection, the T Reflection, is particularly well defined below the North Gjallar Ridge (NGR) between 7 and 8 s TWT. The T Reflection is located near the volcanic lava flows emplaced during the NE Atlantic breakup (similar to 55-54 Ma ago) and coincides with the top of the LCB, forming a mid-crustal dome. Based on structural and temporal relationships, we show that the dome clearly influences the structural... |
| Tipo: Text |
Palavras-chave: Mantle plume; Norwegian margin; Underplating; Breakup; Modelling; Rifting; Volcanic margins. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1042.pdf |
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| Charvis, P; Recq, M; Operto, S; Brefort, D. |
| Seismic refraction profiles were carried out in 1983 and 1987 throughout the Kerguelen Isles (southern Indian Ocean, Terres Australes and Antarctiques Francaises, TAAF) and thereafter at sea on the Kerguelen-Heard Plateau during the MD66/KeOBS cruise in 1991. These profiles substantiate the existence of oceanic-type crust beneath the Kerguelen-Heard Plateau stretching from 46 degrees S to 55 degrees S, including the archipelago. Seismic velocities within both structures are in the range of those encountered in 'standard' oceanic crust. However, the Kerguelen Isles and the Kerguelen-Heard Plateau differ strikingly in their velocity-depth structure. Unlike the Kerguelen Isles, the thickening of the crust below the Kerguelen-Heard Plateau is caused by a 17 km... |
| Tipo: Text |
Palavras-chave: Hotspot; Kerguelen; Lower crust; Oceanic islands; Oceanic plateau; Underplating. |
| Ano: 1995 |
URL: https://archimer.ifremer.fr/doc/00297/40791/39809.pdf |
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