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A new starting point for the history of the central Atlantic ArchiMer
Sahabi, Mohamed; Aslanian, Daniel; Olivet, Jean-louis.
A new starting point for the history of the central Atlantic. The first oceanic crust in the central Atlantic is usually thought to have a Middle Jurassic age. The new interpretation of the two key parameters, the African homologue of the East Coast Magnetic Anomaly and the situation of the Triassic salt basin of Morocco and Novia Scotia, shows that this age was underestimated by about 20 Ma. In our kinematic reconstruction, the first oceanic crust begins at the Late Sinemurian. This difference in age is crucial for the evolution of those margins and we discuss here its consequences.
Tipo: Text Palavras-chave: Cinématique; Bassin à évaporites; Anomalie magnétique; Atlantique central; Cinematic; Salt basin; Magnetic anomaly; Central Atlantic.
Ano: 2004 URL: http://archimer.ifremer.fr/doc/2004/publication-437.pdf
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A new starting point for the South and Equatorial Atlantic Ocean ArchiMer
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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A two-step process for the reflooding of the Mediterranean after the Messinian Salinity Crisis ArchiMer
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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An alternative early opening scenario for the Central Atlantic Ocean ArchiMer
Labails, Cinthia; Olivet, Jean-louis; Aslanian, Daniel; Roest, Walter.
The opening of the Central Atlantic Ocean basin that separated North America from northwest Africa is well documented and assumed to have started during the Late Jurassic. However, the early evolution and the initial breakup history of Pangaea are still debated: most of the existing models are based on one or multiple ridge jumps at the Middle Jurassic leaving the oldest crust on the American side, between the East Coast Magnetic Anomaly (ECMA) and the Blake Spur Magnetic Anomaly (BSMA). According to these hypotheses, the BSMA represents the limit of the initial basin and the footprint subsequent to the ridge jump. Consequently, the evolution of the northwest African margin is widely different from the northeast American margin. However, this setting is in...
Tipo: Text Palavras-chave: Central Atlantic Ocean; Mesozoic reversals; Volcanism; Fracture zones; Spreading asymmetry; Plate reconstructions.
Ano: 2010 URL: http://archimer.ifremer.fr/doc/00014/12533/17926.pdf
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Asymmetry of the mantle structure beneath the Mid-Atlantic Ridge ArchiMer
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
Ano: 1992 URL: http://archimer.ifremer.fr/doc/00288/39941/38487.pdf
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Axial incision: The key to understand submarine canyon evolution (in the western Gulf of Lion) ArchiMer
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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Chemical systematics of an intermediate spreading ridge: The Pacific-Antarctic Ridge between 56 degrees S and 66 degrees S ArchiMer
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
Ano: 2000 URL: https://archimer.ifremer.fr/doc/00000/10578/9396.pdf
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Comment on 'A new scheme for the opening of the South Atlantic Ocean and the dissection of an Aptian salt basin' by Trond H. Torsvik, Sonia Rousse, Cinthia Labails and Mark A. Smethurst ArchiMer
Aslanian, Daniel; Moulin, Maryline.
P>Torsvik et al. recently presented a revised model for the opening of the South Atlantic Ocean. According to these authors, this new plate tectonic model is internally consistent and consistent with globally balanced plate motion solutions and takes into account realistic intraplate deformation. However, this model shows a number of kinematic and geological problems that we underline here, together with some comparisons with the new kinematic model recently proposed by Moulin et al.
Tipo: Text Palavras-chave: Plate motions; Continental margins: divergent; Africa; Atlantic Ocean; South America.
Ano: 2010 URL: http://archimer.ifremer.fr/doc/00014/12504/9878.pdf
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Corrigendum to "A new starting point for the South and Equatorial Atlantic Ocean" ArchiMer
Moulin, Maryline; Aslanian, Daniel.
Tipo: Text
Ano: 2010 URL: http://archimer.ifremer.fr/doc/00021/13247/11524.pdf
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Crustal structure of the SW-Moroccan margin from wide-angle and reflection seismic data (the DAKHLA experiment) Part A: Wide-angle seismic models ArchiMer
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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Crustal structure variations along the NW-African continental margin: a comparison of new and existing models from wide-angle and reflection seismic data ArchiMer
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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Deep crustal structure across a young passive margin from wide-angle and reflection seismic data (The SARDINIA Experiment) - I. Gulf of Lion's margin ArchiMer
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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Deep Crustal Structure of the North-West African Margin from Combined Wide-angle and Reflection Seismic Data (MIRROR Seismic Survey) ArchiMer
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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Deep crustal structure of the Tuamotu plateau and Tahiti (French Polynesia) based on seismic refraction data - art. no. 1656 ArchiMer
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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Deep structure of the Santos Basin-São Paulo Plateau System, SE Brazil ArchiMer
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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Deep-penetration heat flow probes raise questions about interpretations from shorter probes ArchiMer
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
Ano: 2001 URL: http://archimer.ifremer.fr/doc/00288/39943/38491.pdf
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Evolution of rifted continental margins: The case of the Gulf of Lions (Western Mediterranean Basin) ArchiMer
Bache, Francois; Olivet, Jean-louis; Gorini, Christian; Aslanian, Daniel; Labails, Cinthia; Rabineau, Marina.
The formation of rifted continental margins has long been explained by numerous physical models. However, field observations are still lacking to validate or constrain these models. This study presents major new observations on the broad continental margin of the Gulf of Lions, based on a large amount of varied data. Two contrasting regions characterize the thinned continental crust of this margin. One of these regions corresponds to a narrow rift zone (40–50 km wide) that was highly thinned and stretched during rifting. In contrast with this domain, a large part of the margin subsided slowly during rifting and then rapidly after rifting. The thinning of this domain cannot be explained by stretching of the upper crust. We can thus recognize a zonation of...
Tipo: Text Palavras-chave: Subsidence; Passive margins; Back-arc; Rifting; Erosion; Stretching; Thinning; Western Mediterranean; Gulf of Lions.
Ano: 2010 URL: http://archimer.ifremer.fr/doc/00001/11230/7736.pdf
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Geological constraints on the evolution of the Angolan margin based on reflection and refraction seismic data (ZaïAngo project) ArchiMer
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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High resolution evolution of terrigenous sediment yields in the Provence Basin during the last 6 Ma: relation with climate and tectonics ArchiMer
Leroux, Estelle; Rabineau, Marina; Aslanian, Daniel; Gorini, Christian; Molliex, Stephane; Bache, Francois; Robin, Cecile; Droz, Laurence; Moulin, Maryline; Poort, Jeffrey; Rubino, Jean-loup; Suc, Jean-pierre.
Basin-wide correlation of Messinian units and Plio-Quaternary chronostratigraphic markers (5.3 Ma, 2.6 Ma, 0.9 Ma and 0.45 Ma), the mapping of total sediment thickness and the determination of overall sedimentary volumes enabled us to provide a high-resolution quantitative history of sediment volumes for the last 6 Ma along the Gulf of Lions margin. The results point to (i) a dramatic increase in terrigenous sediment input during the Messinian Salinity Crisis. This increased sedimentation reflects enhanced regional fluvial erosion related to the dramatic fall of Mediterranean base-level. Stronger weathering due to a regional wetter climate probably also increased erosional fluxes. (ii) A sediment input three times higher during the Plio-Quaternary compared...
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Ano: 2017 URL: http://archimer.ifremer.fr/doc/00310/42087/41520.pdf
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Hotspotting called into question ArchiMer
Aslanian, Daniel; Geli, Louis; Olivet, Jean-louis.
Tipo: Text
Ano: 1998 URL: https://archimer.ifremer.fr/doc/00446/55769/59653.pdf
Registros recuperados: 49
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