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| Registros recuperados: 11 | |
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| 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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| Gutscher, Marc-andre; Kopp, Heidrun; Krastel, Sebastian; Bohrmann, Gerhard; Garlan, Thierry; Zaragosi, Sebastien; Klaucke, Ingo; Wintersteller, Paul; Loubrieu, Benoit; Le Faou, Yann; San Pedro, Laurine; Dominguez, Stephane; Rovere, Marzia; De Lepinay, Bernard Mercier; Ranero, Cesar; Sallares, Valenti. |
| The detailed morphology and internal structure of the Calabrian accretionary wedge and adjacent Eastern Sicily margin are imaged in unprecedented detail by a combined dataset of multi-beam bathymetry and high-resolution seismic profiles. The bathymetric data represent the results of 6 recent marine geophysical surveys since 2010 as well as a compilation of earlier surveys presented as a 2 arc-sec (60 m) grid. Several distinct morpho-tectonic provinces are identified including: the deeply incised Malta–Hyblean Escarpment, numerous submarine canyons, broad regions of relatively flat seafloor dominated by fields of sediment waves, the gently undulating anticlinal fold-and-thrust belts of the external Calabrian accretionary wedge and the adjacent portion of... |
| Tipo: Text |
Palavras-chave: Subduction; Active faults; Eurasia-Africa plate boundary; Bathymetry; Seismic profiles; Accretionary wedge. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00366/47685/47853.pdf |
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| Tisserand, Amandine; Malaize, Bruno; Jullien, Elsa; Zaragosi, Sebastien; Charlier, Karine; Grousset, Francis. |
| A reconstruction of northwest African summer monsoon strength during the cold marine isotopic stage (MIS) 6 indicates a link to the seasonal migration of the Intertropical Convergence Zone (ITCZ). High-resolution studies of eolian dust supply and sea surface temperature recorded in marine core MD03-2705, on the Mauritanian margin, provide a better understanding about the penultimate glacial history of northwestern African aridity/humidity and upwelling coastal activity. Today, site MD03-2705 experiences increased upwelling and dust flux during the winter months, when the ITCZ is in a southerly position. Analyses of foraminifera isotopic composition suggest that during MIS 6.5 (180 - 168 ka) the average position of the ITCZ migrated north, marked by an... |
| Tipo: Text |
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| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00218/32937/31444.pdf |
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| Soulet, Guillaume; Menot, Guillemette; Garreta, Vincent; Rostek, Frauke; Zaragosi, Sebastien; Lericolais, Gilles; Bard, Edouard. |
| Chronologies of sediments that document the last glacial history of the Black Sea "Lake" are hampered by issues relating to reservoir age. Regulated by basin hydrology, reservoir ages represent a tool that could potentially be used to better understand the response of Black Sea "Lake" hydrology to climate change. Therefore, deciphering reservoir age evolution is crucial both for better constraining the basin chronological framework and for providing new insights into our understanding of Black Sea "Lake" hydrology. By tuning a meaningful new high-resolution geochemical dataset (obtained from core MD04-2790) to a climate reference record, here, we propose a reliable chronology spanning the last 32 kyr BP. The chronology is compared to a large AMS... |
| Tipo: Text |
Palavras-chave: Black Sea; Reservoir age; Radiocarbon; Last Glacial; Last Deglaciation; Paleoclimate. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00043/15379/12817.pdf |
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| Mary, Yannick; Eynaud, Frederique; Colin, Christophe; Rossignol, Linda; Brocheray, Sandra; Mojtahid, Meryem; Garcia, Jennifer; Peral, Marion; Howa, Helene; Zaragosi, Sebastien; Cremer, Michel. |
| This paper documents the evolution over the last 10 kyr of one of the key parameters of climate: sea-surface temperatures (SSTs) in the North Atlantic. We focus on the southern Bay of Biscay, a highly sensitive oceanographic area regarding the dynamics of the North Atlantic subpolar and subtropical gyres (SPG and STG respectively). This site furthermore offers unique sedimentary environments characterized by exceptional accumulation rates, enabling the study of Holocene archives at (infra) centennial scales. Our results mainly derive from planktonic foraminiferal association analysis on two cores from the southern Landes Plateau. These associations are used as the basis of modern analogue technique transfer functions to track past hydrographical changes.... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53177/55077.pdf |
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| Toucanne, Samuel; Zaragosi, Sebastien; Bourillet, Jean-francois; Dennielou, Bernard; Jorry, Stephan; Jouet, Gwenael; Cremer, Michel. |
| Sequence stratigraphic models predict increased sediment delivery to deep-water areas during sea-level lowstand. The Armorican margin (Bay of Biscay, western European margin) is an interesting area to test this hypothesis because the margin has a wide continental shelf, still partly flooded during sea-level lowstand, and the Armorican turbidite system has experienced fluctuating sediment fluxes since the last glacial period. The stratigraphic response of the Armorican turbidite system to sea-level oscillations and climate changes was assessed for the last 35,000 years through the study of the Guilcher, Crozon and Audierne levees. Millenial-timescale resolution chronostratigraphy allowed us to reconstruct the sediment accumulation and turbidite frequency,... |
| Tipo: Text |
Palavras-chave: Armorican margin; Bay of Biscay; Turbidite systems; Turbidity currents; Levee growth; External forcing; Deglaciation; Source-to-sink. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00070/18147/15708.pdf |
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| Kong, Eleonore; Zaragosi, Sebastien; Schneider, Jean-luc; Garlan, Thierry; Bachelery, Patrick; Sabine, Marjolaine; San Pedro, Laurine. |
| In the Ionian Sea, the subduction of the Nubia plate underneath the Eurasia plate leads to an important sediment remobilization on the Calabrian Arc and the Mediterranean Ridge. These events are often associated with earthquakes and tsunamis. In this study, we analyze gravity-driven deposits in order to establish their recurrence time on the Calabrian Arc and the western Mediterranean Ridge. Four gravity cores collected on ridges and slope basins of accretionary prisms record turbidites, megaturbidites, slumping and micro-faults over the last 330,000 years. These turbidites were dated by correlation with a hemipelagic core with a multi-proxy approach: radiometric dating, 18O, b* colour curve, sapropels and tephrochronology. The origin of the gravity-driven... |
| Tipo: Text |
Palavras-chave: Ionian Sea; Accretionary wedges; Palaeoearthquakes; Etna volcanism; Natural hazard; Turbidites. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00638/75012/75691.pdf |
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| Joussain, Ronan; Liu, Zhifei; Colin, Christophe; Duchamp-alphonse, Stephanie; Yu, Zhaojie; Moreno, Eva; Fournier, Lea; Zaragosi, Sebastien; Dapoigny, Arnaud; Meynadier, Laure; Bassinot, Franck. |
| Mineralogical and geochemical analyses conducted on cores located on the active channel-levee system of the northern Bengal Fan are used to establish changes in the weathering pattern and the sediment transport of the Himalayan system, and evaluate the effect of Indian summer monsoon rainfall during the Holocene. Our data indicate that during the Holocene, sediments from the northern Bengal Fan originate mainly from the G-B river system without any significant changes in the relative contribution of these rivers. From 9.8 to around 6 ka, relatively low smectite/(illite+chlorite) ratios and relatively high K/Si* ratios indicate high physical denudation rates of the Himalayan highlands together with a rapid transfer of the detrital material to the Bengal... |
| Tipo: Text |
Palavras-chave: Bengal Fan; Chemical weathering; Sr and Nd isotopic compositions; Physical erosion; Clay mineralogy. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00393/50416/51143.pdf |
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| Toucanne, Samuel; Soulet, Guillaume; Freslon, Nicolas; Jacinto, Ricardo Silva; Dennielou, Bernard; Zaragosi, Sebastien; Eynaud, Frederique; Bourillet, Jean-francois; Bayon, Germain. |
| Reconstructing Northern Hemisphere ice-sheet oscillations and meltwater routing to the ocean is important to better understand the mechanisms behind abrupt climate changes. To date, research efforts have mainly focused on the North American (Laurentide) ice-sheets (LIS), leaving the potential role of the European Ice Sheet (EIS), and of the Scandinavian ice-sheet (SIS) in particular, largely unexplored. Using neodymium isotopes in detrital sediments deposited off the Channel River, we provide a continuous and well-dated record for the evolution of the EIS southern margin through the end of the last glacial period and during the deglaciation. Our results reveal that the evolution of EIS margins was accompanied with substantial ice recession (especially of... |
| Tipo: Text |
Palavras-chave: European ice-sheet; Channel River; Meltwater; Deglaciation; Neodymium; Termination. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00272/38346/36675.pdf |
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| Eynaud, Frederique; Malaize, Bruno; Zaragosi, Sebastien; De Vernal, Anne; Scourse, James; Pujol, Claude; Cortijo, Elsa; Grousset, Francis E.; Penaud, Aurelie; Toucanne, Samuel; Turon, Jean-louis; Auffret, Gerard. |
| During the late Quaternary, both external and internal forcings have driven major climatic shifts from glacial to interglacial conditions. Nonlinear climatic steps characterized the transitions leading to these extrema, with intermediate excursions particularly well expressed in the dynamics of the Northern Hemisphere cryosphere. Here we document the impact of these dynamics on the north-eastern North Atlantic Ocean, focussing on the 35-10 ka interval. Sea-surface salinities have been reconstructed quantitatively based on two independent methods from core MD95-2002, recovered from the northern Bay of Biscay adjacent to the axis of the Manche paleoriver outlet and thus in connection with proximal European ice sheets and glaciers. Quantitative... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00086/19762/20100.pdf |
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| Toucanne, Samuel; Zaragosi, Sebastien; Bourillet, Jean-francois; Marieu, Vincent; Cremer, Michel; Kageyama, Masa; Van Vliet-lanoe, Brigitte; Eynaud, Frederique; Turon, Jean-louis; Gibbard, Philip L.. |
| The Fleuve Manche (English Channel) palaeoriver represents the largest river system that drained the European continent during Pleistocene lowstands, particularly during the Elsterian (Marine Isotope Stage 12) and Saalian Drenthe (MIS 6) glaciations when extensive ice advances into the North Sea area forced the central European rivers to flow southwards to the Bay of Biscay (NE Atlantic). Numerous long piston cores and high-resolution acoustic data from the northern Bay of Biscay have been correlated using a well-constrained chronostratigraphical framework, and for the first time allow the estimation of the discharge of the Fleuve Manche palaeoriver at the end of the last glacial period (i.e. Weichselian). Our results, discussed in the light of... |
| Tipo: Text |
Palavras-chave: Fleuve Manche palaeoriver; English Channel; Sediment and meltwater discharge; European ice sheet; Deglaciation; Termination 1; North Sea area; European drainage network. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11310/7858.pdf |
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| Registros recuperados: 11 | |
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