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Registros recuperados: 12
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Acquisition of detrital magnetization in four turbidites 5
Tanty, Cyrielle; Valet, Jean-pierre; Carlut, Julie; Bassinot, Franck; Zaragosi, Sebastien.
Turbiditic events are mostly avoided in paleomagnetic studies and therefore their remanence and magnetic properties are poorly described. Turbidites are exempt of bioturbation and potentially provide pertinent information about depositional remanence. We studied four quaternary turbidites of different origins in marine sediment cores. Upward fining of both magnetic and sedimentary fractions indicates that coarser grains reached the bottom first. We observe a progressive shallowing of the magnetic inclinations between the upper and bottom layers of the turbidites that increases with the size of the events and obeys a simple linear scaling law. Measurements of magnetic anisotropy suggest that hydrodynamic conditions prevailing during deposition seem to be...
Tipo: Text Palavras-chave: Detrital remanence; Turbidite; Sediment; Rock magnetism; Magnetization.
Ano: 2016 URL: https://archimer.ifremer.fr/doc/00421/53226/54792.pdf
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Benthic foraminiferal response to sedimentary disturbance in the Capbreton canyon (Bay of Biscay, NE Atlantic) 5
Duros, Pauline; Silva Jacinto, Ricardo; Dennielou, Bernard; Schmidt, S.; Martinez Lamas, Ruth; Gautier, Emeric; Roubi, Angelique; Gayet, Nicolas.
Living (Rose Bengal stained) and dead benthic foraminifera were investigated at 6 deep-sea sites sampled in the Capbreton canyon area (Bay of Biscay, France). Three sites were located along the canyon axis at 301 m, 983 m and 1478 m and 3 stations were positioned on adjacent terraces at 251 m, 894 m and 1454 m. Sedimentary features indicate that frequent sedimentary disturbances of different magnitudes occur along the Capbreton canyon axis and adjacent terraces. Such environmental conditions cause the presence of very particular benthic environments. Along the 6 studied sites, different foraminiferal responses to various sedimentary patterns are observed revealing the complexity of this canyon environment. Some sites (Gitan 3 (canyon axis), Gitan 5 (canyon...
Tipo: Text Palavras-chave: Benthic foraminifera; Capbreton canyon; Habitat disturbance; Turbidite; Submarine canyon.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00360/47121/47052.pdf
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First evidence of a mid-Holocene earthquake-triggered megaturbidite south of the Chile Triple Junction 5
Piret, Loic; Bertrand, Sebastien; Kissel, Catherine; De Pol-holz, Ricardo; Tamayo Hernando, Alvaro; Van Daele, Maarten.
Megaturbidites have been the focus of many paleoseismic and paleoenvironmental studies because they can provide evidence for catastrophic and/or hazardous events with potentially major environmental implications. During a recent research cruise in Baker Fjord, Chile (47°54′S–74°30′W), a megaturbidite was described between the Northern and Southern Patagonian Icefields. Here, we aim to determine the depositional processes of the megaturbidite and identify its origin. Based on the turbidite's location, a possible origin was the early Holocene drainage of paleo-lake General Carrera, which was recently proposed in the literature as having produced a Glacial Lake Outburst Flood (GLOF) that drained through Baker Fjord. Due to the fjord's location in a subduction...
Tipo: Text Palavras-chave: Turbidite; Sediment provenance; Patagonia; Holocene; Earthquake.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00425/53700/54551.pdf
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Geological overview of the Angola-Congo margin, the Congo deep-sea fan and its submarine valleys 5
Savoye, Bruno; Babonneau, Nathalie; Dennielou, Bernard; Bez, Martine.
The Congo deep-sea fan is one of the largest fans in the world still affected by presently active turbidity currents. The present activity of deep-sea sedimentary processes is linked to the existence of a direct connection between the Congo River estuary and the Congo canyon head that allows relatively continuous sediment feeding of the deep-sea environment, in spite of a wide continental shelf (150 km). Because of this important activity in terms of sedimentary processes, the deep-sea environment of the Congo-Angola margin presents major interests concerning physical, chemical and biological studies near the seafloor. The main aim of this paper is to present the initial geological context of the BioZaire Program, showing a synthesis of the major results...
Tipo: Text Palavras-chave: Congo Angola margin; Congo channel; Sedimentary deposits; Turbidite.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/00000/11128/7848.pdf
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Major modification of sediment routing by a large Mass Transport Deposit in the Gulf of Lions (Western Mediterranean) 5
Dennielou, Bernard; Jegou, I.; Droz, Laurence; Jouet, Gwenael; Cattaneo, Antonio; Berné, Serge; Aslanian, Daniel; Loubrieu, Benoit; Rabineau, Marina; Bermell, Sylvain.
In the Gulf of Lions (Western Mediterranean), the emplacement of a large (160 km3) Mass Transport Deposit, the Rhone Western Mass Transport Deposit (RWMTD), at the base of slope, aside the Rhone deep-sea fan between 1800 and 2700 m water depth, resulted in a major modification of the sediment routing by clogging a drainage network and blocking at the base of slope sediments that were previously routed into the Valencia channel and the Balearic abyssal plain. The RWMTD was sourced from sediments of the western flank of the Rhone upper fan and the adjacent base of slope. The mass transport deposit is characterized by a transparent seismic facies and sediment cores show that it is composed of a stiff laminated muddy lithofacies characteristic of the Rhone fan...
Tipo: Text Palavras-chave: Gulf of Lions; Ebro margin; Sediment routing; Rhone deep-sea fan; Canyon; Mass transport deposit; Turbidite.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00480/59175/61813.pdf
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Morphology and sedimentary architecture of a modern volcaniclastic turbidite system: The Cilaos fan, offshore La Reunion Island 5
Sisavath, Emmanuelle; Babonneau, Nathalie; Saint-ange, Francky; Bachelery, Patrick; Jorry, Stephan; Deplus, Christine; De Voogd, Beatrice; Savoye, Bruno.
Recent oceanographic surveys revealed the existence of five volcaniclastic deep-sea fans off La Reunion Island. The Cilaos fan is a large volcaniclastic submarine fan, connected to rivers that episodically experience torrential floods through a narrow and steep shelf-slope system. New piston cores presented in this study together with echosounder profiles give new insight into the evolution, of this extensive and sand-rich turbidite system. The Cilaos fan extends over 15,000 km(2) on an abyssal plain and is compartmentalized by topographic highs. Located southwest of the island, the sedimentary system consists of a canyon area and a deep sea fan divided into a proximal and a distal fan. The proximal fan is characterized by its wide extent and...
Tipo: Text Palavras-chave: Turbidite; Deep-sea fan; Volcaniclastic; La Reunion Island.
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00056/16704/14203.pdf
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Morphology, structure, composition and build-up processes of the active channel-mouth lobe complex of the Congo deep-sea fan with inputs from remotely operated underwater vehicle (ROV) multibeam and video surveys 5
Dennielou, Bernard; Droz, Laurence; Babonneau, Nathalie; Jacq, Celine; Bonnel, Cedric; Picot, Marie; Le Saout, Morgane; Saout, Yohan; Bez, Martine; Savoye, Bruno; Olu, Karine; Rabouille, Christophe.
The detailed structure and composition of turbiditic channel-mouth lobes is still largely unknown because they commonly lie at abyssal water depths, are very thin and are therefore beyond the resolution of hull-mound acoustic tools. The morphology, structure and composition of the Congo turbiditic channel-mouth lobe complex (90×40 km; 2525 km2) were investigated with hull-mounted swath bathymetry, air gun seismics, 3.5 kHz sub-bottom profiler, sediment piston cores and also with high-resolution multibeam bathymetry and video acquired with a Remote Operating Vehicle (ROV). The lobe complex lies 760 km off the Congo River mouth in the Angola abyssal plain between 4740 and 5030 m deep. It is active and is fed by turbidity currents that deposit several...
Tipo: Text Palavras-chave: Congo deep-sea fan; Lobe; Lobe complex; Channel; Channel-Lobe Transition Zone; Angola basin; Slump; Slide; Debrite; Turbidite; ROV; Bathymetry; Seismic; Sediment core.
Ano: 2017 URL: https://archimer.ifremer.fr/doc/00378/48976/49383.pdf
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The Congolobe project, a multidisciplinary study of Congo deep-sea fan lobe complex: Overview of methods, strategies, observations and sampling 5
Rabouille, C.; Olu, Karine; Baudin, F.; Khripounoff, Alexis; Dennielou, Bernard; Arnaud-haond, Sophie; Babonneau, Nathalie; Bayle, Christophe; Beckler, J.; Bessette, Sandrine; Bombled, B.; Bourgeois, S.; Brandily, Christophe; Caprais, Jean-claude; Cathalot, Cecile; Charlier, K.; Corvaisier, R.; Croguennec, Chantal; Cruaud, Perrine; Decker, Carole; Droz, L.; Gayet, Nicolas; Godfroy, Anne; Hourdez, S.; Le Bruchec, J.; Saout, Johan; Le Saout, Marie-helene; Lesongeur, Francoise; Martinez, P.; Mejanelle, L.; Michalopoulos, P.; Mouchel, Olivier; Noel, Philippe; Pastor, Lucie; Picot, M.; Pignet, Patricia; Pozzato, L.; Pruski, A. M.; Rabiller, Manuella; Raimonet, M.; Ragueneau, O.; Reyss, J. L.; Rodier, Philippe; Ruesch, Blandine; Ruffine, Livio; Savignac, F.; Senyarich, C.; Schnyder, J.; Sen, Arunima; Stetten, E.; Sun, Ming Yi; Taillefert, M.; Teixeira, S.; Tisnerat-laborde, N.; Toffin, Laurent; Tourolle, Julie; Toussaint, F.; Vetion, G.; Jouanneau, J. M.; Bez, M..
The presently active region of the Congo deep-sea fan (around 330 000 km2), called the terminal lobes or lobe complex, covers an area of 2500 km2 at 4700–5100 m water depth and 750–800 km offshore. It is a unique sedimentary area in the world ocean fed by a submarine canyon and a channel-levee system which presently deliver large amounts of organic carbon originating from the Congo River by turbidity currents. This particularity is due to the deep incision of the shelf by the Congo canyon, up to 30 km into the estuary, which funnels the Congo River sediments into the deep-sea. The connection between the river and the canyon is unique for major world rivers. In 2011, two cruises (WACS leg 2 and Congolobe) were conducted to simultaneously investigate the...
Tipo: Text Palavras-chave: Chemosynthetic habitats; Congo deep-sea fan; Fine sediment; Sedimentation rate; Seafloor morphology; Turbidite; Vesicomyidae.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00335/44580/44298.pdf
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Turbidite chronostratigraphy off Algiers, central Algerian margin: A key for reconstructing Holocene paleo-earthquake cycles 5
Babonneau, Nathalie; Cattaneo, Antonio; Ratzov, Gueorgui; Deverchere, Jacques; Yelles-chaouche, Abdelkarim; Lateb, Tassadit; Bachir, Roza Si.
Northern Algeria is threatened by moderate to large magnitude earthquakes resulting from the slow convergence between the African and European plates. Main active faults are located offshore along the Algerian coast, as exemplified by the 2003 Mw 6.9 Boumerdès earthquake. This event triggered numerous and widespread turbidity currents over ∼ 150 km along strike in the Algerian basin (reaching 2800 m of water depth) and demonstrates the multi-source and multi-path characteristics of earthquake-triggered turbidity flows along this margin segment. We rely on the sedimentological analysis of five cores located at the toe of the Algiers margin, close to the 2003 cable break sites, to explore the potential for Holocene turbidite paleoseismology. Radiocarbon...
Tipo: Text Palavras-chave: Algerian margin; Marine paleoseismology; Turbidite; Holocene.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00356/46701/46563.pdf
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Turbidite deposition in the southern South China Sea during the last glacial: Evidence from grain-size and major elements records 5
Zhao, Yulong; Liu, Zhifei; Colin, Christophe; Xie, Xin; Wu, Qiong.
High-resolution grain size and major element geochemical measurements were performed on the marine sediments of Core MD05-2895 to help understand the formation of turbidite sequences. Grain-size results show that these turbidite sediments contain more coarse sediment grains than normal marls. The coarse sediment grains are mostly derived from relict sediments on the Sunda Shelf. Relict sediments are composed mainly of quartz, feldspar, tephra and a few titaniferous or ferruginous heavy minerals. Corresponding to the concentration of these minerals, increases in Si/Al, K/Al, Ti/Al and Fe/Al ratios are observed in the turbidite layers. As all the observed turbidite sequences were deposited during the last glacial, the occurrence of these turbidity events is...
Tipo: Text Palavras-chave: Southern South China Sea; Last glacial; Turbidite; Grain-size analyses; XRF Core Scanner.
Ano: 2011 URL: https://archimer.ifremer.fr/doc/00213/32464/30929.pdf
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Turbidity current activity along the flanks of a volcanic edifice: The mafate volcaniclastic complex, La Réunion Island, Indian Ocean 5
Mazuel, Aude; Sisavath, Emmanuelle; Babonneau, Nathalie; Jorry, Stephan; Bachelery, Patrick; Delacourt, Christophe.
Recent marine geophysical surveys reveal the existence of well-developed volcaniclastic deep-sea fans around La Réunion Island, Indian Ocean. The Mafate turbidite complex, located in the northwestern part of the island, is a large sedimentary system formed by two coalescent-like volcaniclastic deep-sea fans: the Mafate fan and the Saint-Denis fan. They are both connected to terrestrial rivers supplying sediment produced by erosion on the island, particularly during austral summer cyclonic floods. Through the integration of marine geophysical data (including bathymetry, backscatter multibeam sounder images, TOBI side-scan sonar images and seismic reflection profiles) and piston cores, a submarine morpho-sedimentary map of the surface architecture of the...
Tipo: Text Palavras-chave: Deep-sea fan; Turbidite; Volcaniclastic; Land-to-sea transfer; La Reunion Island; Late Quaternary.
Ano: 2016 URL: http://archimer.ifremer.fr/doc/00312/42273/41597.pdf
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Vertical grain-size variability within a turbidite levee: Autocyclicity or allocyclicity? A case study from the Rhone neofan, Gulf of Lions, Western Mediterranean 5
Dennielou, Bernard; Huchon, Agnès; Beaudouin, Célia; Berne, Serge.
The fining upward trend commonly described on levees of turbidite systems can be either attributed to changes in the sediment supply (external forcing = allocyclic) or changes in the spillover processes related to the growth of the levee (internal forcing = autocyclic). However the real causes remain speculative and difficult to demonstrate. Knowledge of vertical change in flow velocity (or grain size) in turbidity currents, of the turbidity current's height, as well as the growth rate of a levee are theoretically sufficient to describe the evolution of the grain size of a leveed turbidite sequence deposited by spillover processes. A piston core (MD99-2344) retrieved on the right levee of the Petit-Rhone neofan, sampled an 8.50 m long turbidite sequence...
Tipo: Text Palavras-chave: Allocyclicity; Amocyclicity; Grain size; Channel levee; Turbidite.
Ano: 2006 URL: http://archimer.ifremer.fr/doc/2006/publication-2311.pdf
Registros recuperados: 12
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