|
|
|
| Registros recuperados: 50 | |
|
| |
|
| |
|
|
| Moulin, Maryline; Aslanian, Daniel; Olivet, Jean-louis; Contrucci, Isabelle; Matias, Luis; Geli, Louis; Klingelhoefer, Frauke; Nouze, Herve; Rehault, Jean Pierre; Unternehr, Patrick. |
| Deep penetration multichannel reflection and Ocean Bottom Seismometer wide-angle seismic data from the CongoAngola margin were collected in 2000 during the ZaïAngo cruise. These data help constrain the deep structure of the continental margin, the geometry of the pre-salt sediment layers and the geometry of the Aptian salt layer. Dating the deposition of the salt relative to the chronology of the margin formation is an issue of fundamental importance for reconstructing the evolution of the margin and for the understanding of the crustal thinning processes. The data show that the crust thins abruptly, from a 3040 km thickness to less than 10 km, over a lateral distance of less than 50 km. The transitional domain is a 180-km-wide basin. The pre-salt sediment... |
| Tipo: Text |
Palavras-chave: Deep seismic reflection and refraction; Sub salt imaging; Transitional domain; Crustal structure; Non volcanic passive continental margin. |
| Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/2005/publication-349.pdf |
| |
|
| |
|
| |
|
|
| Olivet, Jean-louis; Auzende, Jean-marie; Mascle, Jean; Monti, S.; Pastouret, Léo; Pautot, Guy. |
| Recent data on the western Mediterranean basin (Joides cruise, Montadert et al., 1970, Auzende et al., 1971, Le Borgne et al., 1971) and its connection with the evolution of the Atlantic area (Le Pichon et al., 1970, Talwani et al., 1971, Le Pichon et al. in writing) lead us, like other authors (Dubourdieu, 1962, Stanley and Mutti, 1968, Ryan, 1969 amongst others) to admit the theory of an opening of the Algero-provencal basin during the Cenozoic era. A series of arguments drove us to formulate the hypothesis of an Oligocene age (in process). This work is in line with this perspective. [...] |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1971 |
URL: http://archimer.ifremer.fr/doc/1971/publication-4907.pdf |
| |
|
|
| Bache, Francois; Gorini, C; Olivet, Jean-louis; Rabineau, Marina; Aslanian, Daniel; Baztan, Juan; Moulin, Maryline. |
| The Messinian erosional surface that can be observed on the Mediterranean margins is a good marker of the relative lowering of the sea level which happened during the Messinian salinity crisis. The estimate of the volume of Miocene sediments on the Gulf of Lion platform gives a minimum eroded volume of 5 300 Km . The eroded layer reaches one kilometre in numerous places (Figures 2 and 3). This volume demonstrates the erosion of the continental shelf in the Gulf of Lion and does not include the eroded volumes in the Rhone valley, the surroundings of the Gulf of Lion and on the slope. Thus, this minimum eroded volume is logically transferred towards the basin. |
| Tipo: Text |
|
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-4680.pdf |
| |
|
|
| Baztan, Juan; Berne, Serge; Olivet, Jean-louis; Rabineau, Marina; Aslanian, Daniel; Gaudin, Mathieu; Rehault, Jean Pierre; Canals, M. |
| A detailed morphological analysis of the outer shelf and continental slope of the Western Gulf of Lion is presented, based on swath bathymetry data together with sub-bottom profiles and high resolution seismic reflection profiles. These data reveal two main erosive features, of very different dimensions: the axial incision and the canyon's major valley. The height of axial incisions' flanks with respect to the canyon deepest point (the thalweg) ranges from 40 to 150 m. It creates a small axial erosive path within the canyon's major valley, which is typically bounded by flanks of more than 700 m in height. We interpret the axial incision observed in the sea floor as the imprint of turbidity currents that eroded the floor of canyons during phases of... |
| Tipo: Text |
Palavras-chave: Submarine canyon; Axial incision; Gulf of Lion. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-353.pdf |
| |
|
|
| Auzende, Jean-marie; Bonnin, Jean; Olivet, Jean-louis. |
| Based on the study of some seismic-reflection profiles, we demonstrate that the identified sedimentary units show a structural anomaly at the bottom of the North-African continental margin compared to the situation observed on the other margins of the western Mediterranean basin: all the deep Messinian and infra-Messinian deposits are subjected to a flexure when reaching the North-African margin; the created depression is filled by the plio-quaternary deposits. This observation, set back in the geodynamic context of the western Mediterranean, leads to the following interpretation: the North-African margin is a very active margin at a very early evolutional stage. The abnormal structure of the gravity field in the considered region confirms this... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1975 |
URL: http://archimer.ifremer.fr/doc/1975/publication-5473.pdf |
| |
|
|
| Bache, Francois; Olivet, Jean-louis; Gorini, Christian; Rabineau, Marina; Baztan, Juan; Aslanian, Daniel; Suc, Jean-pierre. |
| Though the late Miocene "Messinian Salinity Crisis" has been intensely researched along the circum-Mediterranean basins, few studies have focused on the central part of the Mediterranean Basin and, especially, the pre-salt deposits. To improve our knowledge of the Messinian events, it is imperative to better understand this domain. In this study, we provide a more complete understanding of this central domain in the Provence Basin. We were able to recognize: a) thick marine detrital series (up to 1000 m) derived from the Messinian subaerial erosion which is partly prolongated in the distal part by b) a thick unit of deep marine deposits (up to 800 m) prior to the evaporites; c) a thick presumed alternation of detritals and evaporites (1500 m) below the... |
| Tipo: Text |
Palavras-chave: Erosion; Detrital deposits; Miocene; Provence Basin; Mediterranean; Gulf of Lions; Salinity Crisis; Messinian. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6870.pdf |
| |
|
|
| Olivet, Jean-louis; Sichler, Bertrand; Thonon, Pierre; Le Pichon, Xavier; Martinais, Guy; Pautot, Guy. |
| The Gibbs fracture moves the central Rift of the Mid-Atlantic Ridge 370 km to the left at latitude 53O north. It is the only fracture located between Europe and America that can be compared to the large equatorial fractures mapped by B.C. Heezen and M. Tharp between Africa and America. Its morphology is a major element in the understanding of the structural framework of the northern Atlantic Ocean. The identification of its extension to the west was one of the proposed focuses for the first Noratlante expedition of the R.V. Jean-Charcot (conducted in August 1969 under the authority of the C.N.E.X.O.). J.T. Wilson (2) suggested, in his hypothesis of sea-bed spreading from the dorsal axis, that such fractures are "transforming faults" that are active only... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1970 |
URL: http://archimer.ifremer.fr/doc/1970/publication-4875.pdf |
| |
|
| |
|
|
| Olivet, Jean-louis; Le Pichon, Xavier; Laubier, Lucien. |
| The cold waters from the Norwegian Sea are the main source of the underflow system in the northern Atlantic Ocean (10) (pl. 1, fig. 1b). The role of these currents in the formation of large sediment ripples has been demonstrated in some recent studies [(2), (3)]. As in the southern Atlantic Ocean, the observations suggested that their influence had been of importance since the Eocene era (6). From a sedimentological point of view, it appears that the Gibbs fracture (4) represents a very important feature in this system; this structure both forms a deep opening through the Mid-Atlantic Ridge and a dam across the abyssal plain to the northeast of Newfoundland. This dam, which is still active today, though partly flooded, must have been continuous from the... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1970 |
URL: http://archimer.ifremer.fr/doc/1970/publication-4882.pdf |
| |
|
|
| Rabineau, Marina; Leroux, Estelle; Aslanian, Daniel; Bache, F.; Gorini, Christian; Moulin, Maryline; Molliex, Stephane; Droz, Laurence; Dos Reis, Antonio; Rubino, J. L.; Guillocheau, Francois; Olivet, Jean-louis. |
| Passive margins are characterised by an important tectonic and thermal subsidence, which favours a good preservation of sedimentary sequences. This sedimentation in turn enhances the subsidence because of loading effects. We present here a direct method based on sedimentary markers seen on seismic data, to evaluate total subsidence rates from the coast to the outer shelf and to the deep basin in the Gulf of Lion, from the beginning of massive salt deposition up to present day (the last circa 6 Ma) with minimal theoretical assumptions. On the shelf, the Pliocene-Quaternary subsidence shows a seaward tilt reaching a rate of 240 m/Ma (±15 m/Ma) at the shelf break (70 km from the present day coastline) (i.e. a total angle of rotation of 0.88° (0.16°/Ma)). We... |
| Tipo: Text |
Palavras-chave: Subsidence; Pliocene-quaternary; Messinian salinity crisis; Isostasy; Mediterranean Sea; Gulf of Lion. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00171/28176/32147.pdf |
| |
|
| |
|
|
| Ondreas, Helene; Aslanian, Daniel; Geli, Louis; Olivet, Jean-louis; Briais, Anne. |
| The spreading rate at the Pacific-Antarctic Ridge (PAR) increases rapidly from 54 mm/yr near Pitman Fracture Zone (FZ) up to 76 mm/yr near Udintsev FZ, resulting in three domains of axial morphology: an axial valley south of Pitman FZ, an axial high north of Saint Exupery FZ, and in between, the transitional domain extends over 650 km. It comprises sections of ridge with an axial valley or an axial high and generally displays a very low cross-sectional relief. It is also characterized by two propagating rifts. Two domains of different seafloor roughness appear south of Udintsev FZ: east of 157 degreesW these two domains are separated by a 1000-km V-shaped boundary. West of 157 degreesW, the boundary approximately coincides with Chron 3a or Chron 4. The... |
| Tipo: Text |
Palavras-chave: Spreading; Segmentation; Geomorphology; Seafloor; Ridge. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/2001/publication-438.pdf |
| |
|
| |
|
|
| Gutscher, Marc-andre; Olivet, Jean-louis; Aslanian, Daniel; Eissen, Jp; Maury, Rene. |
| Since flat subduction of the Nazca Plate beneath Peru was first recognized in the 1970s and 1980s a satisfactory explanation has eluded researchers. We present evidence that a lost oceanic plateau (Inca Plateau) has subducted beneath northern Peru and propose that the combined buoyancy of Inca Plateau and Nazca Ridge in southern Peru supports a 1500 km long segment of the downgoing slab and shuts off arc volcanism. This conclusion is based on an analysis of the seismicity of the subducting Nazca Plate, the structure and geochemistry of the Marquesas Plateau as well as tectonic reconstructions of the Pacific¿Farallon spreading center 34 to 43 Ma. These restore three sub¿parallel Pacific oceanic plateaus; the Austral, Tuamotu and Marquesas, to two Farallon... |
| Tipo: Text |
Palavras-chave: Nazca Plate; Subduction; Nazca Ridge; Peru; Reconstruction. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/1999/publication-360.pdf |
| |
|
|
| Rabineau, Marina; Berne, Serge; Aslanian, Daniel; Olivet, Jean-louis; Joseph, Philippe; Guillocheau, François; Bourillet, Jean-francois; Le Drezen, Eliane; Granjeon, Didier. |
| The wide continental shelf of the Gulf of Lion (up to 70 km) has been the object of numerous investigations since the early days of oceanography. Yet, the question of sequences duration, the mechanisms of deposition and factors implied remained unanswered. A study of a very dense grid of Very High Resolution (VHR) seismic reflection (Sparker) data associated with surficial cores both, collected by IFREMER between 1992 and 2001 on the outer shelf and upper slope offshore of Sète in the Languedoc region gives a new insight into these issues. Analysis of the 3D geometry of the sedimentary record reveals a basic depositional pattern consisting of a pair of horizontally juxtaposed and downlapping prisms. Prism PI with low angle clinoforms (<1°) lies on the... |
| Tipo: Text |
Palavras-chave: Stratigraphic modelling; Cores; High resolution seismic data; Glacioeustatism; Climatic cycles; Gulf of Lion; Western Mediterranean. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-368.pdf |
| |
|
|
| Feraud, Gilbert; Gastaud, Janine; Auzende, Jean-marie; Olivet, Jean-louis; Cornen, Guy. |
| Gorringe Bank is situated on the Europe-Africa plate boundary at the eastern end of the Azores-Gibraltar fracture zone. It has two summits. Gettysburg Bank to the southwest and Ormonde Bank to the northeast. We applied the 40Ar/39AR stepwise heating method to date six samples of the alkaline volcanic rocks. Two gabbros from the Ormonde Bank and a dolerite from the Gettysburg Bank. The results suggest that the alkaline volcanism lasted probably for less than 6 Ma(66-60 Ma). Although the nature of this volcanism precludes any subduction feature during its setting. the alkaline volcanism of Ormonde is probably linked to Upper Cretaceous/Eocene compressive tectonic events. The basement rocks of Gorringe Bank reveal disturbed 40Ar/39Ar age spectra. One... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/1981/publication-5365.pdf |
| |
| Registros recuperados: 50 | |
|
|
|
