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| Muller, R; Sdrolias, M; Gaina, C; Roest, Walter. |
| We present four companion digital models of the age, age uncertainty, spreading rates, and spreading asymmetries of the world's ocean basins as geographic and Mercator grids with 2 arc min resolution. The grids include data from all the major ocean basins as well as detailed reconstructions of back-arc basins. The age, spreading rate, and asymmetry at each grid node are determined by linear interpolation between adjacent seafloor isochrons in the direction of spreading. Ages for ocean floor between the oldest identified magnetic anomalies and continental crust are interpolated by geological estimates of the ages of passive continental margin segments. The age uncertainties for grid cells coinciding with marine magnetic anomaly identifications, observed or... |
| Tipo: Text |
Palavras-chave: Seafloor spreading; Geodynamic; Plate kinematic; Ocean floor; Digital isochrons. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3900.pdf |
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| D'Acremont, E; Leroy, S; Beslier, Mo; Bellahsen, N; Fournier, M; Robin, C; Maia, M; Gente, P. |
| The Gulf of Aden is a young and narrow oceanic basin formed in Oligo-Miocene time between the rifted margins of the Arabian and Somalian plates. Its mean orientation, N75 degrees E, strikes obliquely (50 degrees) to the N25 degrees E opening direction. The western conjugate margins are masked by Oligo-Miocene lavas from the Afar Plume. This paper concerns the eastern margins, where the 19-35 Ma breakup structures are well exposed onshore and within the sediment-starved marine shelf. Those passive margins, about 200 km distant, are non-volcanic. Offshore, during the Encens-Sheba cruise we gathered swath bathymetry, single-channel seismic reflection, gravity and magnetism data, in order to compare the structure of the two conjugate margins and to reconstruct... |
| Tipo: Text |
Palavras-chave: Continental margins; Gulf of Aden; Ocean-continent transition; Plate divergence; Rifted margin; Seafloor spreading. |
| Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/00230/34079/32539.pdf |
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| D'Acremont, Elia; Leroy, Sylvie; Maia, Marcia; Patriat, Philippe; Beslier, Marie-odile; Bellahsen, Nicolas; Fournier, Marc; Gente, Pascal. |
| Magnetic and gravity data gathered during the Encens-Sheba cruise (2000 June) in the eastern Gulf of Aden provide insights on the structural evolution of segmentation from rifted margins to incipient seafloor spreading. In this study, we document the conjugate margins asymmetry, confirm the location of the ocean-continent transition (OCT) previously proposed by seismic data, and describe its deep structure and segmentation. In the OCT, gravity models indicate highly thinned crust while magnetic data indicate presence of non-oceanic high-amplitude magnetic anomalies where syn-rift sediments are not observed. Thus, the OCT could be made of ultra-stretched continental crust intruded by magmatic bodies. However, locally in the north, the nature of the OCT... |
| Tipo: Text |
Palavras-chave: Gulf of Aden; Kinematic evolution; Ocean-continent transition; Passive continental margin; Seafloor spreading; Segmentation. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00234/34561/33314.pdf |
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| Amon Kothias, J.B.; Guiral, D.; Sankaré, Y.; Kaba, N.; Etien, N.. |
| Des cartographies par survol aérien ont été réalisées de décembre 1986 à septembre 1989pour décrire l'évolution saisonnière des macrophytes colonisant les eaux de surface du secteur oriental de la lagune Ebrié. Le couvert végétal de ce secteur lagunaire et des lagunes qui lui sont associées est essentiellement constitué de Eichhornia crassipes (jacinthe d'eau). Son expansion saisonnière est favorisée par la dessalure des eaux lagunaires due aux précipitations. Sa migration dans le milieu lagunaire est assurée par la crue du fleuve Comoé. L'ouverture du grau de Bassam a entraîné son élimination temporaire de la zone estuarienne nouvellement crée. |
| Tipo: Journal Contribution |
Palavras-chave: Seafloor spreading; Cartography. |
| Ano: 1991 |
URL: http://hdl.handle.net/1834/5163 |
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