|
|
|
| Registros recuperados: 33 | |
|
| |
|
|
| Baudin, Francois; Stetten, Elsa; Schnyder, Johann; Charlier, Karine; Martinez, Philippe; Dennielou, Bernard; Droz, Laurence. |
| The Congo River, the second largest river in the world, is a major source of organic matter for the deep Atlantic Ocean because of the connection of its estuary to the deep offshore area by a submarine canyon which feeds a vast deep-sea fan. The lobe zone of this deep-sea fan is the final receptacle of the sedimentary inputs presently channelled by the canyon and covers an area of ~2500 km². The quantity and the source of organic matter preserved in recent turbiditic sediments from the distal lobe of the Congo deep-sea fan were assessed using Rock-Eval pyrolysis analyses. Six sites, located at approximately 5000 m water-depth, were investigated. The mud-rich sediments of the distal lobe contain high amounts of organic matter (~3.5 to 4% Corg), the origin... |
| Tipo: Text |
Palavras-chave: Recent sediments; Congo turbidite system; Organic matter; Rock-Eval pyrolysis. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00369/48018/48095.pdf |
| |
|
|
| Auffret, Gérard-andré; Zaragosi, S; Voisset, Michel; Droz, Laurence; Loubrieu, Benoit; Pelleau, Pascal; Savoye, R; Bourillet, Jean-francois; Baltzer, Agness; Bourquin, S; Dennielou, Bernard; Coutelle, Alain; Weber, N; Floch, Gilbert. |
| During the SEDIFAN 1 cruise we surveyed the bathymetry and the acoustic properties of the surface sediment of the Celtic Deep Sea Fan. We also collected Kullenberg cores in order to study recent sedimentary processes. From the bathymetry survey it is relatively easy to recognize the main areas of modern fan. The upper fan included a large sedimentary ridge which constitutes the right levee of the prominent meandering Whittard valley. After its confluence with the Shamrock valley the course of the Whittard valley is abruptly deflected to the south. At a short distance to the south the valley divides into two upper-fan channels, the Celtic channel to the west being the deeper one. This point constitutes the centre of a radiating pattern which is developed on... |
| Tipo: Text |
Palavras-chave: Paléoclimat; Turbidité; Sédiment; Quaternaire; Eventail profond; Palaeoclimate; Turbidity; Sediment; Quaternary; Deep sea fan. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-525.pdf |
| |
|
|
| Badhani, Shray; Cattaneo, Antonio; Collico, Stefano; Urgeles, Roger; Dennielou, Bernard; Leroux, Estelle; Colin, Florent; Garziglia, Sebastien; Rabineau, Marina; Droz, Laurence. |
| The Gulf of Lions presents recurring mass-transport deposits (MTDs) within the Plio-Quaternary sediments suggesting a long history of mass movements. The two large, surficial MTDs are located on the eastern and western levee of the Rhone canyon over an area exceeding 6000 km2 and volumes exceeding 100 km3. Both MTDs were emplaced 21 ka ago (peak of the Last Glacial Maximum), suggesting a common trigger. Here, we present a multidisciplinary high-resolution geophysical, sedimentological and in-situ geotechnical study of the source and deposit areas of both MTDs to characterise distinct expressions of sediment deformation as well as their spatial and chronological distributions. We show the internal structure of mass movements and resulting MTDs with... |
| Tipo: Text |
|
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00611/72289/71122.pdf |
| |
|
| |
|
|
| Hardy, William; Penaud, Aurelie; Marret, Fabienne; Bayon, Germain; Marsset, Tania; Droz, Laurence. |
| A new 44 kyr long record of dinoflagellate (phytoplanktonic organisms) cysts (dinocysts) is presented from a marine sediment core collected on the Congolese margin with the aim of reconstructing past hydrological changes in the equatorial eastern Atlantic Ocean since Marine Isotopic Stage (MIS) 3. Our high-resolution dinocyst record indicates that significant temperature and moisture variations occurred across the glacial period, the last deglaciation and the Holocene. The use of specific dinocyst taxa, indicative of fluvial, upwelling and Benguela Current past environments for instance, provides insights into the main forcing mechanisms controlling palaeohydrological changes on orbital timescales. In particular, we are able, for the last 44 kyr, to... |
| Tipo: Text |
|
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00349/46006/45675.pdf |
| |
|
|
| Miramontes Garcia, Elda; Jouet, Gwenael; Cattaneo, Antonio; Thereau, Estelle; Guerin, Charline; Jorry, Stephan; Droz, Laurence. |
| The upper slopes of continental margins are very energetic areas where nepheloid layers are often observed. Multibeam bathymetry, sub-bottom profiler and multi-channel highresolution seismic reflection data acquired during the PAMELA-MOZ04 survey in the Mozambique Channel revealed the presence of sand dunes on the upper slope at 120-250 m water depth. The dunes migrate upslope and their crests are oblique to the contours. They are medium to large dunes, with wavelengths between 20 and 150 m and heights between 0.15 and 1.50 m, and their size decreases upslope. Seismic reflection data of the water column show internal solitary waves travelling offshore in the depth range of the dune field. The formation of the dune field could be related to the interaction... |
| Tipo: Text |
|
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00499/61049/64460.pdf |
| |
|
|
| Leroux, Estelle; Rabineau, Marina; Aslanian, Daniel; Granjeon, Didier; Droz, Laurence; Gorini, Christian. |
| Determining the relative importance of factors interacting to control stratigraphic organization is a key issue in sedimentology. The Pliocene-Quaternary chronostratigraphy on the Gulf of Lions platform is still poorly constrained, giving rise to different interpretations of the evolution of its subsidence through time. This paper examines the Pliocene-Quaternary sedimentary filling of the Gulf of Lion's shelf with Dionisos, a numerical stratigraphic model. Our results show that a constant subsidence rate accurately reproduces the observed geometries, whereas a varying subsidence rate reproduces them only if the acceleration of subsidence is limited. At this time-scale, a third-order eustatic curve is also reappraised: a higher resolution curve (built... |
| Tipo: Text |
|
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00173/28384/26752.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 |
| |
|
|
| Croguennec, Claire; Ruffine, Livio; Dennielou, Bernard; Baudin, Francois; Caprais, Jean-claude; Guyader, Vivien; Bayon, Germain; Brandily, Christophe; Le Bruchec, Julie; Bollinger, Claire; Germain, Yoan; Droz, Laurence; Babonneau, Nathalie; Rabouille, Christophe. |
| On continental margins, sulfate reduction occurs within the sedimentary column. It is coupled with the degradation of organic matter and the anaerobic oxidation of methane. These processes may be significantly disturbed by sedimentary events, leading to transient state profiles for the involved chemical species. Yet, little is known about the impact of turbidity currents and mass wasting on the migration of chemical species and the redox reactions in which they are involved. Due to its connection to the River, the Congo deep-sea fan continuously receives huge amount of organic matter-rich sediments primarily transported by turbidity currents, which impact on the development of the associated ecosystems (Rabouille et al., 2016). Thus, it is well suited to... |
| Tipo: Text |
|
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00363/47410/47403.pdf |
| |
|
|
| Pattier, France; Loncke, L.; Imbert, Patrice; Gaullier, V.; Basile, C.; Maillard, Alexandre; Roest, Walter; Patriat, Martin; Vendeville, B. C.; Marsset, Tania; Bayon, Germain; Cathalot, Cecile; Caprais, Jean-claude; Bermell, Sylvain; Sotin, Christine; Hebert, Bertil; Mercier De Lepinay, Marion; Lebrun, J. F.; Marcaillou, B.; Heuret, A.; Droz, Laurence; Graindorge, David; Poetisi, E.; Berrenstein, H.. |
| The Demerara plateau, located offshore French Guiana and Suriname, is part of a passive transform continental margin particularly prone to develop slope instabilities, probably in relation to the presence of a free distal border along its steep continental slope. Slope failure occurred at different periods (Cretaceous to Neogene) and shows an overall retrogressive evolution through time. Upslope these failure headscarp, an enigmatic regional MioPliocene unconformity has been discovered through the interpretation of new academic and industrial datasets. The aim of this work is to describe and understand the origin of this surface. Our analysis shows that this unconformity is made of a series of valleys that cross-cut sedimentary strata. Each one of these... |
| Tipo: Text |
Palavras-chave: Unconformity; Hydrate pockmark; Slide; Contourite; Valley; Canyon; Demerara plateau. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00271/38193/36735.pdf |
| |
|
| |
|
|
| Leroux, Estelle; Aslanian, Daniel; Rabineau, Marina; Moulin, Maryline; Granjeon, Didier; Gorini, Christian; Droz, Laurence. |
| Deep Earth dynamics impact so strongly on surface geological processes that we can use sediment palaeo-markers as a window into the deeper Earth. Derived from climatic and tectonic erosive actions on the continents, and related to eustasy, subsidence and isostasy, the sediment in a deep basin is the main recorder of these processes. Nevertheless, defining and quantifying the relative roles of parameters that interact to give the final sedimentary architecture is not a simple task. Using a 3D-grid of seismic and wide-angle data, boreholes and numerical stratigraphic modelling, we propose here a quantification of post-rift vertical movements in the Provençal Basin (West Mediterranean) involving three domains of subsidence: seaward tilting on the platform and... |
| Tipo: Text |
|
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00253/36466/37817.pdf |
| |
|
|
| 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 |
|
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00614/72597/71595.pdf |
| |
|
|
| Rabouille, C.; Dennielou, Bernard; Baudin, F.; Raimonet, M.; Droz, Laurence; Khripounoff, Alexis; Martinez, P.; Mejanelle, L.; Michalopoulos, P.; Pastor, Lucie; Pruski, A.; Ragueneau, Olivier; Reyss, J.-l.; Ruffine, Livio; Schnyder, J.; Stetten, E.; Taillefert, M.; Tourolle, Julie; Olu, Karine. |
| Carbon and silicon cycles at the Earth surface are linked to long-term variations of atmospheric CO2 and oceanic primary production. In these cycles, the river-sea interface is considered a biogeochemical hotspot, and deltas presently receive and preserve a major fraction of riverine particles in shallow water sediments. In contrast, periods of glacial maximum lowstand were characterized by massive exports of sediments to the deep-sea via submarine canyons and accumulation in deep-sea fans. Here, we calculate present-day mass balances for organic carbon (OC) and amorphous silica (aSi) in the terminal lobe complex of the Congo River deep-sea fan as an analogue for glacial periods. We show that this lobe complex constitutes a megasink with the current... |
| Tipo: Text |
Palavras-chave: Present; Paleoceanography; South Atlantic; Inorganic geochemistry; Organic geochemistry; Sedimentology-marine cores. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00511/62289/66720.pdf |
| |
|
|
| Droz, Laurence. |
| L'éventail sous-marin profond du Petit-Rhône constitue la majeure partie du glacis du Golfe du Lion (Méditerranée nord-occidentale). Approximativement 1200 km de profils bathymétriques (12 kHz) et environ 3500 km de profils de sismique réflexion continue haute résolution en ont permis une étude détaillée. Les résultats combinés de l'analyse morphologique et sismique ont permis de mettre en évidence la structuration de l'édifice, le mode d'organisation de ses sédiments, et de montrer que leur mise en place s'est effectuée sous des régimes, et donc par des processus hydrodynamiques, variant au cours du temps. |
| Tipo: Text |
|
| Ano: 1983 |
URL: http://archimer.ifremer.fr/doc/00042/15327/12663.pdf |
| |
|
|
| Fierens, Ruth; Droz, Laurence; Toucanne, Samuel; Raisson, François; Jouet, Gwenael; Babonneau, Nathalie; Miramontes Garcia, Elda; Landurain, Steven; Jorry, Stephan. |
| The morphology and present-day sediment distribution of the Zambezi turbidite system was investigated using new bathymetric and sub-bottom profiler data as part of the PAMELA research project. The Zambezi turbidite system is composed of two depositional systems: a channelized fan (the Zambezi Fan) and a semi-confined fan (in the lntermediate Basin). The Zambezi Fan includes the Zambezi Valley, which is deeply incised in the Mozambique Channel and is more than three times as large and deep as the great Tanzanian and North Atlantic Mid-Ocean channels. The erosion in the Zambezi Valley is evidenced by its V-shaped morphology and the existence of a U-shaped thalweg affected by several generations of incisions. Based on echo facies and cores from literature,... |
| Tipo: Text |
Palavras-chave: Zambezi turbidite system; Late Quaternary; Multibeam bathymetry; Sub-bottom seismic profiles. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00483/59425/62240.pdf |
| |
|
|
| Calves, Gerome; Toucanne, Samuel; Jouet, Gwenael; Charrier, Simon; Thereau, Estelle; Etoubleau, Joel; Marsset, Tania; Droz, Laurence; Bez, M.; Abreu, V.; Jorry, Stephan; Mulder, T.; Lericolais, Gilles. |
| Geophysical data and sampling of the Golo Basin (East Corsica margin) provide the opportunity to study mass balance in a single drainage system over the last 130 kyr, by comparing deposited sediments in the sink and the maximum eroded volume in the source using total denudation proxies. Evaluation of the solid sediments deposited offshore and careful integration of uncertainties from the age model and physical properties allow us to constrain three periods of sedimentation during the last climatic cycle. The peak of sedimentation initiated during Marine Isotopic Stage (MIS) 3 (ca. 45 ka) and lasted until late in MIS 2 (ca. 18 ka). This correlates with Mediterranean Sea palaeoclimatic records and the glaciation in high altitude Corsica. The yield of solid... |
| Tipo: Text |
|
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00087/19779/17480.pdf |
| |
|
|
| Lastras, G; Canals, M; Urgeles, R; Amblas, D; Ivanov, M; Droz, Laurence; Dennielou, Bernard; Fabres, J; Schoolmeester, T; Akhmetzhanov, A; Orange, D; Garcia Garcia, A. |
| The Cap de Creus canyon, northwestern Mediterranean Sea, belongs to a complex network of submarine canyons cutting the western Gulf of Lion continental shelf and opening into the larger Sete canyon. Swath bathymetry data, MAKAM deep-towed side-scan sonar imagery and 5 kHz high resolution seismic reflection profiles show striking morphologies in the Cap de Creus canyon floor and walls. As a consequence of the canyon head and the upper reach severe incision, the continental shelf dramatically narrows in front of the Creus Cape promontory. The upper canyon has a flat-bottomed thalweg incised in a megascale sediment furrow field displaying hyperbolic seismic facies. The tens of kilometres long linear furrows extend also over the middle canyon down to 1400 in... |
| Tipo: Text |
Palavras-chave: Gulf of Lion; Bedform; Swath bathymetry; Side scan sonar; Submarine canyon. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3602.pdf |
| |
|
|
| Ciobanu, Maria Cristina; Rabineau, Marina; Droz, Laurence; Revillon, Sidonie; Ghiglione, J. -f.; Dennielou, Bernard; Jorry, Stephan; Kallmeyer, J.; Etoubleau, Joel; Pignet, Patricia; Crassous, Philippe; Vandenabeele-trambouze, Odile; Laugier, J.; Guegan, Matthieu; Godfroy, Anne; Alain, Karine. |
| An interdisciplinary study was conducted to evaluate the relationship between geological and paleoenvironmental parameters and the bacterial and archaeal community structure of two contrasting subseafloor sites in the Western Mediterranean Sea (Ligurian Sea and Gulf of Lion). Both depositional environments in this area are well-documented from paleoclimatic and paleooceanographic point of views. Available data sets allowed us to calibrate the investigated cores with reference and dated cores previously collected in the same area, and notably correlated to Quaternary climate variations. DNA-based fingerprints showed that the archaeal diversity was composed by one group, Miscellaneous Crenarchaeotic Group (MCG), within the Gulf of Lion sediments and of nine... |
| Tipo: Text |
|
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00090/20171/17826.pdf |
| |
| Registros recuperados: 33 | |
|
|
|
