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Registros recuperados: 53 | |
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Moulin, Maryline; Aslanian, Daniel; Unternehr, Patrick. |
The opening of the Equatorial and South Atlantic Oceans is still a matter of debate, particularly as concerns the locations of the intraplate deformation. We propose here a critical review of the kinematic models published since Bullard et al., 1965, based on a series of constraints: new interpretation of the magnetic anomalies, seafloor isochrons, flow lines, fracture zones, continental and oceanic homologous structures and radiometric dating of igneous rocks. All of these models present numerous unexplained misfits (gaps, overlaps and misalignments). We present here a new evolution of the Equatorial and South Atlantic Ocean from the tightest reconstruction to Chron C34. This new model confirms the hypothesis of a northward propagation of the South... |
Tipo: Text |
Palavras-chave: Initial kinematic reconstruction; South and Equatorial Atlantic Oceans; Intraplate deformation; Magnetic anomalies. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00000/11160/7883.pdf |
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Bache, Francois; Popescu, Speranta-maria; Rabineau, Marina; Gorini, Christian; Suc, Jean-pierre; Clauzon, Georges; Olivet, Jean-louis; Rubino, Jean-loup; Melinte-dobrinescu, Mihaela Carmen; Estrada, Ferran; Londeix, Laurent; Armijo, Rolando; Meyer, Bertrand; Jolivet, Laurent; Jouannic, Gwenael; Leroux, Estelle; Aslanian, Daniel; Dos Reis, Antonio Tadeu; Mocochain, Ludovic; Dumurdzanov, Nikola; Zagorchev, Ivan; Lesic, Vesna; Tomic, Dragana; Cagatay, M. Namik; Brun, Jean_pierre; Sokoutis, Dimitrios; Csato, Istvan; Ucarkus, Gulsen; Cakir, Ziyadin. |
The Messinian Salinity Crisis is well known to have resulted from a significant drop of the Mediterranean sea level. Considering both onshore and offshore observations, the subsequent reflooding is generally thought to have been very sudden. We present here offshore seismic evidence from the Gulf of Lions and re-visited onshore data from Italy and Turkey that lead to a new concept of a two-step reflooding of the Mediterranean Basin after the Messinian Salinity Crisis. The refilling was first moderate and relatively slow accompanied by transgressive ravinement, and later on very rapid, preserving the subaerial Messinian Erosional Surface. The amplitude of these two successive rises of sea level has been estimated at =500 similar to m for the first rise and... |
Tipo: Text |
Palavras-chave: Paleo environmental changes; Miocene pliocene boundary; Section marche province; Earliest zanclean age; Desiccated deep basin; Di tetto formations; Northern apennines; Southern France; Decic basin; Depositional environments. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00076/18774/16490.pdf |
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Goslin, J; Aslanian, Daniel. |
Altimetry data from repetitive orbits of the GEOSAT satellite are interpreted together with sea-floor depths over the Mid-Atlantic Ridge, South of Iceland and South of the Azores. Geoid / Topography ratios indicate a strong asymmetry of the upper mantle structure in oceanic areas created since 35 My, extending several hundreds kilometers from Iceland to the Azores. A model including interaction between the MAR and two layers of mantle convection seems adequate to produce the observed asymmetry. |
Tipo: Text |
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Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00288/39941/38487.pdf |
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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 |
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Vlastelic, Ivan; Dosso, Laure; Bougault, Henri; Aslanian, Daniel; Geli, Louis; Etoubleau, Joel; Bohn, Marcel; Joron, Jl; Bollinger, C. |
Axial bathymetry, major/trace elements, and isotopes suggest:that the Pacific-Antarctic Ridge (PAR) between 56 degrees S and 66 degrees S is devoid of any hotspot influence. PAR (56-66 degrees 5) samples have in-average lower Sr-87/Sr-86 and Nd-143/Nd-144 and higher Pb-206/(204)pb than northern Pacific midocean ridge basalts (MORB), and also than MORE from the other oceans. The high variability of Pb isotopic ratios (compared to Sr and Nd) can be due to either a;general high mu (HIMU) (high U/Pb) affinity of the southern Pacific upper mantle or to a mantle event first recorded in time by Pb isotopes. Compiling the results of this study with those from the PAR between 53 degrees S and 57 degrees S gives a continuous view of mantle characteristics from south... |
Tipo: Text |
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Ano: 2000 |
URL: https://archimer.ifremer.fr/doc/00000/10578/9396.pdf |
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Evain, Mikael; Schnurle, Philippe; Lepretre, Angelique; Verrier, Fanny; Watremez, Louise; Thompson, Joseph Offei; De Clarens, Philippe; Aslanian, Daniel; Moulin, Maryline. |
Deep seismic acquisitions and a new kinematic study recently highlighted the presence of continental crust in both the southern Mozambique's Coastal Plain (MCP) and further offshore in the North Natal Valley (NNV). Such findings falsify previous geodynamic scenarios based on the kinematic overlap between Antarctica and Africa plates, thus profoundly impacting our understanding East-Gondwana break-up. Using an updated position of Antarctica with respect to Africa this study reconsider the formation mechanism of East-African margins and most specifically of the Limpopo margin (LM). Coincident wide-angle and multi-channel seismic data acquired within the PAMELA project are processed to image the sedimentary and deep crustal structure along a profile that runs... |
Tipo: Text |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00678/79004/81397.pdf |
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Klingelhoefer, Frauke; Labails, Cinthia; Cosquer, Emmanuel; Rouzo, Stephane; Geli, Louis; Aslanian, Daniel; Olivet, Jean-louis; Sahabi, M.; Nouze, Herve; Unternehr, P.. |
A total 1500 km of seismic reflection and wide-angle profiles were acquired off the southern Moroccan margin during the DAKHLA cruise, a joint project of Ifremer, the Universities of Brest, El Jadida and Lisbon and Total. The shots along two profiles parallel to the margin and two profiles perpendicular to the margin were also recorded by ocean bottom seismometers (OBS). The profiles perpendicular to the margin were additionally extended on land using 14 stations on the northern profile and 11 stations on the southern profile. Modelling of the reflection and wide-angle seismic data reveals a 10 km deep sedimentary basin including two high velocity carbonate layers. Lateral crustal thinning is observed from a 27 km thick crystalline continental crust to a 7... |
Tipo: Text |
Palavras-chave: Ocean continent transition; Keyword wide angle seismic; Southern Moroccan margin. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6410.pdf |
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Klingelhoefer, Frauke; Biari, Youssef; Sahabi, Mohamed; Aslanian, Daniel; Schnabel, Michael; Matias, Luis; Benabdellouahed, Massinissa; Funck, Thomas; Gutscher, Marc-andre; Reichert, Christian; Austin, James A.. |
Deep seismic data represent a key to understand the geometry and mechanism of continental rifting. The passive continental margin of NW-Africa is one of the oldest on earth, formed during the Upper Triassic–Lower Liassic rifting of the central Atlantic Ocean over 200 Ma. We present new and existing wide-angle and reflection seismic data from four study regions along the margin located in the south offshore DAKHLA, on the central continental margin offshore Safi, in the northern Moroccan salt basin, and in the Gulf of Cadiz. The thickness of unthinned continental crust decreases from 36 km in the North to about 27 km in the South. Crustal thinning takes place over a region of 150 km in the north and only 70 km in the south. The North Moroccan Basin is... |
Tipo: Text |
Palavras-chave: Moroccan continental margin; Wide-angle seismic; Passive margins; Deep structure; Plate reconstruction. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00316/42685/42058.pdf |
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Moulin, Maryline; Klingelhoefer, Frauke; Afilhado, Alexandra; Aslanian, Daniel; Schnurle, Philippe; Nouze, Herve; Rabineau, Marina; Beslier, Marie-odile; Feld, Aurelie. |
The conjugate margins system of the Gulf of Lion and West Sardinia (GLWS) represents a unique natural laboratory for addressing fundamental questions about rifting due to its landlocked situation, its youth, its thick sedimentary layers, including prominent palaeo-marker such as the MSC event, and the amount of available data and multidisciplinary studies. The main goals of the SARDINIA experiment, were to (i) investigate the deep structure of the entire system within the two conjugate margins: the Gulf of Lion and West Sardinia, (ii) characterize the nature of the crust, and (iii) define the geometry of the basin and provide important constrains on its genesis. This paper presents the results of P-wave velocity modelling on three coincident near-vertical... |
Tipo: Text |
Palavras-chave: Marge continentale passive; Structure crustale; Réfraction; Golfe du Lion; Croûte océanique; Domaine transitionnel; Continental passive margin; Crustal structure; Wide-angle seismic; Gulf of Lion; Oceanic crust; Transitional domain. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00283/39422/38269.pdf |
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Biari, Youssef; Klingelhoefer, Frauke; Sahabi, Mohamed; Aslanian, Daniel; Schnurle, Philippe; Berglar, K.; Moulin, Maryline; Mehdi, K.; Graindorge, D.; Evain, Mikael; Benabdellouahed, Massinissa; Reichert, C.. |
The structure of the Moroccan and Nova Scotia conjugate rifted margins is of key importance for understanding the Mesozoic break-up and evolution of the northern central Atlantic Ocean basin. Seven combined multichannel reflection (MCS) and wide-angle seismic (OBS) data profiles were acquired along the Atlantic Moroccan margin between the latitudes of 31.5° and 33° N during the MIRROR seismic survey in 2011, in order to image the transition from continental to oceanic crust, to study the variation in crustal structure and to characterize the crust under the West African Coast Magnetic Anomaly (WACMA). The data were modeled using a forward modeling approach. The final models image crustal thinning from 36 km thickness below the continent to approximately 8... |
Tipo: Text |
Palavras-chave: Moroccan continental margin; Wide-angle seismic modeling; Deep crustal structure; Ocean continent transition. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00273/38401/36726.pdf |
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Patriat, Martin; Klingelhoefer, Frauke; Aslanian, Daniel; Contrucci, Isabelle; Gutscher, Marc-andré; Talandier, Jacques; Avedik, Felix; Francheteau, Jean; Weigel, Wilfried. |
[1] In French Polynesia, the young (< 5Ma) Society Islands appear to result from intraplate volcanism, while the old (>50 Ma) Tuamotu plateau was likely created at or near the ridge axis. The structure of the crust between those two archipelagoes is constrained by a 300 km long refraction seismic profile. Crustal and upper mantle arrivals recorded by 6 OBHs and 3 land stations were used to provide a 2D model of the crust. Results of our study, combined with that of Grevemeyer et al. [2001] show a slight flexure below the Tahiti apron, while a deep crustal root (21 km) underlies the Tuamotu plateau. These structures reflect the different modes of load emplacement and compensation mechanisms between these two volcanic edifices, consistent with an... |
Tipo: Text |
Palavras-chave: Volcanic Islands; Flexure; Hotspot; Refraction methods; French Polynesia. |
Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-621.pdf |
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Evain, Mikael; Afilhado, A.; Rigoti, C.; Loureiro, Afonso; Alves, D.; Klingelhoefer, Frauke; Schnurle, Philippe; Feld, Aurelie; Fuck, R.; Soares, J.; De Lima, M. Vinicius; Corela, C.; Matias, L.; Benabdellouahed, Massinissa; Baltzer, Agnes; Rabineau, Marina; Viana, A.; Moulin, Maryline; Aslanian, Daniel. |
The structure and nature of the crust underlying the Santos Basin-São Paulo Plateau System (SSPS), in the SE Brazilian margin, are discussed based on five wide-angle seismic profiles acquired during the Santos Basin (SanBa) experiment in 2011. Velocity models allow us to precisely divide the SSPS in six domains from unthinned continental crust (Domain CC) to normal oceanic crust (Domain OC). A seventh domain (Domain D), a triangular shape region in the SE of the SSPS, is discussed by Klingelhoefer et al. (2014). Beneath the continental shelf, a ~100 km wide necking zone (Domain N) is imaged where the continental crust thins abruptly from ~40 km to less than 15 km. Toward the ocean, most of the SSPS (Domains A and C) shows velocity ranges, velocity... |
Tipo: Text |
Palavras-chave: Santos Basin; SAo Paulo Plateau; Crustal structure; Wide-angle seismic. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00276/38715/37232.pdf |
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Géli, Louis; Turon, J.-l.; Aslanian, Daniel; Balut, Y.; Beuzart, Paul; Cochran, J.; Francheteau, J.; Harmegnies, Francois; Landuré, Jean-yves; Le Suavé, Raymond; Mazaud, A.; Michel, E.; Normand, Alain; Pichon, Jack; Vlastelic, Ivan. |
Tipo: Text |
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Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00288/39943/38491.pdf |
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Zhang, Yurui; Huck, Thierry; Lique, Camille; Donnadieu, Yannick; Ladant, Jean-baptiste; Rabineau, Marina; Aslanian, Daniel. |
The early Eocene (∼55 Ma) was the warmest period of the Cenozoic and was most likely characterized by extremely high atmospheric CO2 concentrations. Here, we analyze simulations of the early Eocene performed with the IPSL-CM5A2 Earth system model, set up with paleogeographic reconstructions of this period from the DeepMIP project and with different levels of atmospheric CO2. When compared with proxy-based reconstructions, the simulations reasonably capture both the reconstructed amplitude and pattern of early Eocene sea surface temperature. A comparison with simulations of modern conditions allows us to explore the changes in ocean circulation and the resulting ocean meridional heat transport. At a CO2 level of 840 ppm, the early Eocene simulation is... |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75529/76436.pdf |
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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 |
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Registros recuperados: 53 | |
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