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| Registros recuperados: 64 | |
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| Bassetti, Maria-angela; Jouet, Gwenael; Dufois, Francois; Berne, Serge; Rabineau, Marina; Taviani, M. |
| The outer continental shelf of the Gulf of Lions is covered by thick, mainly regressive, sand deposits. A combination of seismic, sedimentological and geochronological methods allows us to demonstrate that a veneer of transgressive sand bodies, few m to less than 1 m thick, reworks these deposits. They take the form of sand ridges and transverse dunes that formed at different periods. In fact, the low-gradient outer shelf of the Gulf of Lions displays a complete record of deglacial history, including not only transgressive deposits that formed during sea-level rise, but also bedfonns that still evolve under episodic high-energy events that occur under more highstand conditions. Core lithology, C-14 dates and regional sea-level curve suggest that the... |
| Tipo: Text |
Palavras-chave: Gulf of Lions; Sand transport; Deglacial transgression; Outer shelf; Sand ridges. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2321.pdf |
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| Cattaneo, Antonio; Badhani, Shray; Caradonna, Cristina; Bellucci, Massimo; Leroux, Estelle; Babonneau, Nathalie; Garziglia, Sebastien; Poort, Jeffrey; Akhmanov, Grigorii G.; Bayon, Germain; Dennielou, Bernard; Jouet, Gwenael; Migeon, Sebastien; Rabineau, Marina; Droz, Laurence; Clare, Michael. |
| Megabeds are thick sedimentary layers extending over thousands square kilometres in deep sea basins and are thought to result from large slope failures triggered by major external events. Such deposits have been found in at least three areas of the Mediterranean Sea. Although their discovery dates back to the early 1980s, many questions remain, concerning their initiation, source area, extent, and the nature of their emplacement. One of the largest previously documented megabeds was emplaced during the Last Glacial Maximum across the Balearic Abyssal Plain with a thickness of 8-10 m in water depths of up to 2800 m. New 3.5 kHz sub-bottom profiles and sediment cores provide greater constraint on the lateral variability of the megabed and allow to map it... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00614/72597/71595.pdf |
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| Badhani, Shray; Cattaneo, Antonio; Dennielou, Bernard; Leroux, Estelle; Colin, Florent; Thomas, Yannick; Jouet, Gwenael; Rabineau, Marina; Droz, Laurence. |
| The Gulf of Lions (NW Mediterranean Sea) is a SW-NE oriented passive continental margin formed since the Oligocene. It presents small to large scale mass movement features suggesting a long history of seafloor instability. Of particular interest are the two surficial large mass-transport deposits along the Rhone turbiditic levee, known as the Rhone Eastern and Western Mass-Transport Deposits (REMTD and RWMTD). With the help of the recently acquired multi-beam bathymetric, sub-bottom profiler, high-resolution seismic and sedimentological data, we investigate the morphology, timing, kinematics, and possible triggering mechanisms of the source area of the REMTD, which we refer to as the Eastern Rhone Interfluve Slide (ERIS). ERIS has an estimated run-out... |
| Tipo: Text |
Palavras-chave: Submarine landslide; Mass transport deposits; Gulf of Lions; Western Mediterranean; Turbiditic levees. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00592/70396/68480.pdf |
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| Alami, Sami; Bonacorsi, Marina; Clabaut, Philippe; Jouet, Gwenael; Pergent-martini, Christine; Pergent, Gerard; Sterckeman, Aurore. |
| The regression of seagrass meadows has been extensively studied over the past few years. Although the causes of this regression may be locally natural, it is more generally related to human impact. In the framework of the HalGolo (2010) and CoralCorse (2013) oceanographic campaigns, acoustic data (mosaic of sonograms and bathymetry), validated by field data (Scuba diving, ROV), were acquired at depths of -10 m and -50 m at the NATURA 2000 site “Grand Herbier de la Plaine Orientale” (Western Mediterranean, Corsica). Processing of this data provided evidence of the scale of this mechanical degradation (trawling scars, mooring, etc.), and enabled its quantification with regard to surface area and scar density. The main degradation was observed between -20 and... |
| Tipo: Text |
Palavras-chave: Anthropogenic impact; Corsica; Side Scan Sonar; Posidonia oceanica; Trawling. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00272/38364/36669.pdf |
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| Fontanier, Christophe; Mamo, Briony; Toucanne, Samuel; Bayon, Germain; Schmidt, Sabine; Deflandre, Bruno; Dennielou, Bernard; Jouet, Gwenael; Garnier, Eline; Sakai, Saburo; Lamas, Ruth Martinez; Duros, Pauline; Toyofuku, Takashi; Sale, Aurelien; Belleney, Deborah; Bichon, Sabrina; Boissier, Audrey; Cheron, Sandrine; Pitel, Mathilde; Roubi, Angelique; Rovere, Mickael; Gremare, Antoine; Dupre, Stephanie; Jorry, Stephan. |
| In this short communication, we present a multidisciplinaty study of sedimentary records collected from a deep-sea interfluve proximal to the mouths of major northwestern Madagascan rivers. For the last 60 years, the seafloor has been repeatedly disturbed by the deposition of organic rich, tropical, terrestrial sediments causing marked reductions in benthic biodiversity. Increased soil erosion due to local land-use, deforestation and intensifying tropical cyclones are potential causes for this sedimentary budget and biodiversity shift. Our marine sedimentary records indicate that until now, these conditions have not occurred within the region for at least 20,000 years. |
| Tipo: Text |
Palavras-chave: Multidisciplinary study; Benthic foraminifera; Land-use; Tropical cyclones. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00413/52488/53276.pdf |
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| Molliex, S.; Jouet, Gwenael; Freslon, Nicolas; Bourles, D. L.; Authemayou, C.; Moreau, Julien; Rabineau, Marina. |
| The Mediterranean domain is characterized by a specific climate resulting from the close interplay between atmospheric and marine processes and strongly differentiated regional topographies. Corsica Island, a mountainous area located in the western part of the Mediterranean Sea is particularly suitable to quantify regional denudation rates in the framework of a source-to-sink approach. Indeed, fluvial sedimentation in East-Corsica margin is almost exclusively limited to its alluvial plain and offshore domain and its basement is mainly constituted of quartz-rich crystalline rocks allowing cosmogenic nuclide Be-10 measurements. In this paper, Holocene denudation rates of catchments from the eastern part of the island of Corsica are quantified relying on in... |
| Tipo: Text |
Palavras-chave: Be-10-derived denudation rates; Schmidt Hammer; Quaternary; Quantitative geomorphology; Weathering. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00380/49082/49655.pdf |
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| Sierro, Francisco J.; Andersen, Nils; Bassetti, Maria-angela; Berne, Serge; Canals, Miquel; Curtis, Jason H.; Dennielou, Bernard; Abel Flores, Jose; Frigola, Jaime; Gonzalez-mora, Beatriz; Grimalt, Joan O.; Hodell, David A.; Jouet, Gwenael; Perez-folgado, Marta; Schneider, Ralph. |
| Direct traces of past sea levels are based on the elevation of old coral reefs at times of sea level high-stands. However, these measurements are discontinuous and cannot be easily correlated with climate records from ice cores. In this study we show a new approach to recognizing the imprint of sea level changes in continuous sediment records taken from the continental slope at locations that were continuously submerged, even during periods of sea level lowstand. By using a sediment core precisely synchronized with Greenland ice cores, we were able to recognize major floods of the Mediterranean continental shelf over the past 270 kyr. During the last glacial period five flooding events were observed at the onset of the warmest Greenland interstadials.... |
| Tipo: Text |
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| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/2009/publication-6969.pdf |
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| Miramontes Garcia, Elda; Garreau, Pierre; Caillaud, Matthieu; Jouet, Gwenael; Pellen, Romain; Hernández-molina, F. Javier; Clare, Michael A.; Cattaneo, Antonio. |
| Contourites are common morphological features along continental margins where currents encounter the seafloor. They can provide long-term archives of palaeoceanography, may be prone to sediment instability, and can have a great potential for hydrocarbon exploration. Despite their importance and increasingly recognised ubiquitous occurrence worldwide, the link between oceanographic processes and contourite features is poorly constrained. In particular, it is unclear under which specific conditions sediments are mobilised, modified and deposited by bottom currents. Here, we aim to determine key bottom current characteristics (velocity and bottom shear stress) affecting contourite deposition, by assuming that recent oceanographic regimes may be extended back... |
| Tipo: Text |
Palavras-chave: Sediment drift; Erosion; Oceanic circulation; Bottom shear stress. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00483/59426/62241.pdf |
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| Pastor, Lucie; Brandily, Christophe; Schmidt, S.; Miramontes, E.; Péron, Maela; Appere, Dennis; Chéron, Sandrine; Boissier, Audrey; Jouet, Gwenael. |
| The NW Madagascar continental margin receives high loads of terrigenous particulate organic matter during the wet season and especially linked to extreme events, originating from two major rivers, the Betsiboka and the Mahavavy Rivers. This particulate matter contains a high content of iron minerals from the weathering of red ferruginous/ferralitic soils of Madagascar. The presence of pockmarks, i.e. gas or fluid expulsion features on the continental slope, testifies to past/present methane migration through the sedimentary column, associated with early diagenetic processes. This study globally aims at deciphering the interactions between episodic sedimentation and geochemical processes influenced by fluids upward migration, using a sediment trap mooring... |
| Tipo: Text |
Palavras-chave: Episodic sedimentation; Madagascar margin; Betsiboka river; Mahavavy river; Progradation; Methane; Geochemistry; Sediment. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00628/73964/73323.pdf |
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| Riboulot, Vincent; Thomas, Yannick; Berne, Serge; Jouet, Gwenael; Cattaneo, Antonio. |
| Gas seeping to the seafloor through structures such as pockmarks may contribute significantly to the enrichment of atmospheric greenhouse gases and global warming. Gas seeps in the Gulf of Lions, Western Mediterranean, are cyclical and pockmark “life” is governed both by sediment accumulation on the continental margin and Quaternary climate changes. 3D seismic data, correlated to multi-proxy analysis of a deep borehole, have shown that these pockmarks are associated with oblique chimneys. The prograding chimney geometry demonstrates the syn-sedimentary and long-lasting functioning of the gas seeps. Gas chimneys have reworked chronologically constrained stratigraphic units and have functioned episodically, with maximum activity around sea-level lowstands.... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00199/31063/29476.pdf |
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| Counts, John; Jorry, Stephan; Leroux, Estelle; Miramontes, Elda; Jouet, Gwenael. |
| Recently acquired data from the Iles Eparses (southwestern Indian Ocean) reveal new information about the geomorphology, depositional processes, and sedimentary deposits on the slopes of atolls and atoll-like platforms. The deposits discussed here lie on the deepwater flanks of isolated, inactive volcanos that are capped by shallow, relatively flat carbonate platforms 45–210 km2 in area. Much of the slope geomorphology is controlled by the underlying volcanic edifice. Steep (~25–35°) upper slopes consist of outcrops of volcanic basement, smooth banks, failure scarps, and channels. Sedimentary features seen in the lower slope and proximal basin (2000–3500 m deep) consist of channels, levees, lobes, and mass transport deposits (MTDs). In places, channels... |
| Tipo: Text |
Palavras-chave: Atoll; Carbonate; Indian Ocean; Slope; Deepwater sediments. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00450/56136/57802.pdf |
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| Prat, Sophie; Jorry, Stephan; Jouet, Gwenael; Camoin, Gilbert; Vella, Claude; Le Roy, Pascal; Caline, Bruno; Boichard, Robert; Pastol, Yves. |
| The study of modern carbonate systems is commonly helps in improving facies interpretation in fossil reefs and in providing analogues of sediment distribution depending on the specific platform configuration (i.e. rimmed shelves and isolated carbonate platforms). This paper deals with a geomorphological and sedimentological study of the Glorieuses Archipelago, an isolated carbonate platform located between the northern tip of Madagascar and Mayotte. The dataset consists of Digital Terrain Model, satellite imagery, and box-sediment samples. Analyses of grain-size and composition of carbonate grains are used to characterize the distribution and heterogeneity of sediment accumulated on the isolated platform. Main results show that the Glorieuses Archipelago... |
| Tipo: Text |
Palavras-chave: Carbonate platform; Modern coral reefs; Pleistocene fossil reefs; Sandwaves. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00326/43761/43318.pdf |
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| Revillon, Sidonie; Jouet, Gwenael; Bayon, Germain; Rabineau, Marina; Dennielou, Bernard; Hemond, Christophe; Berne, Serge. |
| In this study, we undertook a reconnaissance study of sediments provenance in the Gulf of Lions focusing over the last 16 ka. We used geochemical and isotopic tracers to determine the source of sediments and give insight into the weathering conditions prevailing. Sediments samples were selected both onshore and offshore from the western, eastern, and central part of the Gulf of Lions. We analyzed bulk sediments, coarse and fine silt, and clay fractions. Elemental and Nd isotope compositions appeared to differ from one grain size fraction to another one. These are interpreted in terms of zircon addition in the coarse silt fraction for the elemental concentrations and variable sources influences for the Nd isotope compositions. Our results indicate that... |
| Tipo: Text |
Palavras-chave: Geochemistry; Provenance; Sediment; Weathering. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00043/15376/12734.pdf |
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| Jouet, Gwenael; Berne, Serge; Rabineau, Marina; Granjeon, D; Vella, C. |
| Climatic variations over the terminal quaternary have been frequent and quick to occur. It is the environmental response of the evolution of terrestrial orbital parameters with different cyclicities. These climatic transitions impact a number of factors which govern the sedimentation platform, especially as far as the sea level and the sedimentary erosion/transport are concerned. The fluctuations of these factors are directly linked to the regional variability of the climate. |
| Tipo: Text |
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| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-6151.pdf |
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| Labaune, Caroline; Jouet, Gwenael; Berne, Serge; Gensous, B; Tesson, M; Delpeint, Arnaud. |
| In order to achieve a synthesis of the stratigraphic organization of the Deglacial deposits of the inner/middle shelf in front of the Rhone delta plain, we merged high resolution (Mini-sparker and Sparker), and very high resolution (chirp and mudpenetrator) seismic data into a single seismic database. Thus, the merged seismic database improves the lateral correlation between eastern and western parts, separated by the Rhone Incised Valley deposits. As a result the interpretation of seismic units in relation to local and global environmental changes was refined. The Deglacial deposits rest on a basal erosional discontinuity capping a complex of Pleistocene prograding wedges. The identified units make up Transgressive and Highstand Systems Tracts, and are... |
| Tipo: Text |
Palavras-chave: Sediment supply; Glacio eustacy; Seismic stratigraphy; Deglacial deposits; Rhone shelf. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-1364.pdf |
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| Berne, Serge; Jouet, Gwenael; Bassetti, Maria-angela; Dennielou, Bernard; Taviani, M. |
| A unique late Glacial-Preboreal record of changes in sea-level and sediment fluxes originating from the Alps is recorded in the Rhone subaqueous delta in the Western Mediterranean Sea. The compilation of detailed bathymetric charts, together with high-resolution seismic profiles and long cores, reveals the detailed architecture of several sediment lobes, related to periods of decreased sea-level rise and/or increased sediment flux. They are situated along the retreat path of the Rhone distributaries, from the shelf edge and canyon heads up to the modem coastline. They form transgressive backstepping parasequences across the shelf, the late Holocene (highstand) deltas being confined to the inner shelf The most prominent feature is an elongated... |
| Tipo: Text |
Palavras-chave: Western Mediterranean sea; Delta; Younger Dryas; Deglacial; Sea level. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3589.pdf |
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| Nizou, Jean; Dennielou, Bernard; Révillon, Sidonie; Bassetti, Maria-angela; Jouet, Gwenael; Berné, Serge; Nonnotte, Philippe; Liorzou, Celine. |
| Marine mud belts represent potential continuous high-resolution climatic, environmental and anthropogenic archives. In this study, a geochemical record of the Gulf of Lions mud belt, which receives sediments from the Rhône watershed and to a lesser extent from the Languedoc region, is reported from Core KSGC-31. The effects of natural climatic changes and possible anthropogenic disturbances on Holocene sedimentation were ascertained by analysing sedimentation rates, chemical weathering (Al2O3/K2O) and sediment-source shifts (neodymium isotopic ratios; εNd). Measurements of elemental and isotopic lead were used to trace the source and determine the potential vectors of anthropogenic contaminations over the Holocene. High εNd values, recorded from 9000 to... |
| Tipo: Text |
Palavras-chave: Holocene; Marine mud belt; Medieval lead contamination; Roman lead contamination; Sediment source fingerprinting; South of France. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00498/60951/68284.pdf |
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| Registros recuperados: 64 | |
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