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| Registros recuperados: 15 | |
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| Ma, Ruifang; Sépulcre, Sophie; Licari, Laetitia; Haurine, Frédéric; Bassinot, Franck; Yu, Zhaojie; Colin, Christophe. |
| We have measured Cd / Ca ratios of several benthic foraminiferal species and studied benthic foraminiferal assemblages on two cores from the northern Indian Ocean (Arabian Sea and northern Bay of Bengal, BoB), in order to reconstruct variations in intermediate water circulation and paleo-nutrient content since the last deglaciation. Intermediate water Cdw records estimated from the benthic Cd / Ca reflect past changes in surface productivity and/or intermediate-bottom water ventilation. The benthic foraminiferal assemblages are consistent with the geochemical data. These results suggest that during the last deglaciation, the Heinrich Stadial 1 and Younger Dryas (HS1 and YD, respectively) millennial-scale events were marked by a decrease in Cdw values,... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00659/77152/78525.pdf |
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| Yu, Zhaojie; Colin, Christophe; Douville, Eric; Meynadier, Laure; Duchamp-alphonse, Stephanie; Sepulcre, Sophie; Wan, Shiming; Song, Lina; Wu, Qiong; Xu, Zhaokai; Bassinot, Frank. |
| The dissolved Yttrium (Y) and Rare Earth Element (REE) concentrations of seawater samples collected along a north-south hydrological transect within the Bay of Bengal (BoB) have been analyzed to estimate contributions of the Ganges and Brahmaputra (G-B) river inputs to the dissolved REE distribution of the Northern Indian Ocean. Surface water masses of the BoB are characterized by Y/Ho ratios (84) intermediate between the G-B river suspended sediment (41) and water mass from the South Indian Ocean (93). Co-variation of MREE (Middle REE, Sm) and LREE (Light REE, La) concentrations suggests that the dissolved REEs in surface waters (upper 100 m depth) of the BoB (Sm/La = 0.21) appear to derive mainly from the freshwater discharge of the G-B river system. In... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00377/48845/49277.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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| Bonneau, Lucile; Colin, Christophe; Pons-branchu, Edwige; Mienis, Furu; Tisnerat-laborde, Nadine; Blamart, Dominique; Elliot, Mary; Collart, Tim; Frank, Norbert; Foliot, Lorna; Douville, Eric. |
| U‐Th ages and temperatures derived from Li/Mg have been measured on coral fragments of Lophelia pertusa and Madrepora. oculata collected from two sediment cores, which were taken from cold‐water coral (CWC) mounds at 700 ‐ 790 m water depth at the SW Rockall Trough margin. Our data, combined with previous published data, have allowed us to firstly estimate the occurrence of CWC at the SW Rockall Trough margin during the Holocene and, secondly, to better constrain the environmental conditions driving variability in CWC growth. CWC abundance is marked by a pronounced increase in the mid‐Holocene (∼6 ka) and is modulated by millennial‐scale variability throughout the late Holocene. The mid‐Holocene proliferation of CWC coincides with lowest IRD abundances and... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00441/55260/56753.pdf |
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| 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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| 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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| Wu, Qiong; Colin, Christophe; Liu, Zhifei; Thil, Francois; Dubois-dauphin, Quentin; Frank, Norbert; Tachikawa, Kazuyo; Bordier, Louise; Douville, Eric. |
| εNd and normalized Rare Earth Elements (REE) patterns of benthic and planktonic foraminifera and Fe-Mn coatings precipitated on sediments have been investigated for the South China Sea (SCS) to (1) assess the reliability of the extraction of past seawater εNd in the SCS and to (2) reconstruct past hydrological changes during the last 25 kyr. Reductively cleaned mono-specific planktonic foraminifera (Globigerinoides ruber) and mixed benthic foraminifera in core-top sediments from 1500 to 2400 m display similar εNd values to those of the modern Pacific Deep Water (PDW) (εNd of −3.9 to −4.4). Furthermore, the εNd of the reductive cleaning solutions shows similar εNd values to ones obtained on cleaned foraminifera. Combined with PAAS-normalized REE patterns,... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00295/40582/39500.pdf |
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| Dubois-dauphin, Quentin; Montagna, Paolo; Siani, Giuseppe; Douville, Eric; Wienberg, Claudia; Hebbeln, Dierk; Liu, Zhifei; Kallel, Nejib; Dapoigny, Arnaud; Revel, Marie; Pons-branchu, Edwige; Taviani, Marco; Colin, Christophe. |
| We present the neodymium isotopic composition (epsilon Nd) of mixed planktonic foraminifera species from a sediment core collected at 622m water depth in the Balearic Sea, as well as epsilon Nd of scleractinian cold-water corals (CWC; Madrepora oculata, Lophelia pertusa) retrieved between 280 and 442m water depth in the Alboran Sea and at 414m depth in the southern Sardinian continental margin. The aim is to constrain hydrological variations at intermediate depths in the western Mediterranean Sea during the last 20 kyr. Planktonic (Globigerina bulloides) and benthic (Cibicidoides pachyderma) foraminifera from the Balearic Sea were also analyzed for stable oxygen (delta O-18) and carbon (delta C-13) isotopes. The foraminiferal and coral epsilon Nd values... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53193/55001.pdf |
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| Frank, Norbert; Freiwald, Andre; Lopez Correa, Matthias; Wienberg, Claudia; Eisele, Markus; Hebbeln, Dierk; Van Rooij, David; Henriet, Jean-pierre; Colin, Christophe; Van Weering, Tjeerd; De Haas, Henk; Buhl-mortensen, Pal; Roberts, J. Murray; De Mol, Ben; Douville, Eric; Blamart, Dominique; Hatte, Christine. |
| U-series age patterns obtained on reef framework-forming cold-water corals collected over a nearly 6000-km-long continental margin sector, extending from off Mauritania (17 degrees N; northwest Africa) to the southwestern Barents Sea (70 degrees N; northeastern Europe), reveal strong climate influences on the geographical distribution and sustained development of these ecosystems. Over the past three glacial-interglacial cycles, framework-forming cold-water corals (Lophelia pertusa and Madrepora oculata) seem to have predominantly populated reefs, canyons, and patches in the temperate East Atlantic and the Mediterranean Sea. Above 50 degrees N corals colonize reefs in the northern East Atlantic primarily during warm climate periods with the biogeographic... |
| Tipo: Text |
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| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00214/32554/31025.pdf |
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| Frank, Norbert; Ricard, Estelle; Lutringer-paquet, Audrey; Van Der Land, Cees; Colin, Christophe; Blamart, Dominique; Foubert, Anneleen; Van Rooij, David; Henriet, Jean-pierre; De Haas, Henk; Van Weering, Tjeerd. |
| U-series dating of constructional cold-water corals is a powerful tool to reconstruct the evolution of corals on carbonate mounds. Here we have investigated the time framework of corals such as Lophelia pertusa and Madrepora oculata on five different mound settings of the eastern North Atlantic (on Rockall Bank and in Porcupine Seabight), sampled at variable depth and location (610-880 m water depth). We have found that the past 11 ka reflect a period generally favourable for coral development. We further determined local mound growth rates and identified mound surface erosion (framework collapse) during times of active coral framework construction. "Local" vertical mound growth rates vary between less than 5 cm ka(-1) and up to 220 cm ka(-1). We interpret... |
| Tipo: Text |
Palavras-chave: Carbonate mound; Deep sea corals; U-series dating; Climate; Rockall Bank; Porcupine Seabight. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00219/33060/31574.pdf |
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| Yu, Zhaojie; Colin, Christophe; Bassinot, Franck; Wan, Shiming; Bayon, Germain. |
| Chemical weathering of silicate rocks on continents is thought to have played an important role in the evolution of past atmospheric carbon dioxide over geologic timescales. However, the detailed links between continental weathering and climate change over shorter timescales, and their potential impact on sediment records deposited in the ocean, remain poorly understood. Here, we present clay mineralogy and strontium‐neodymium isotopic data for marine sediment records from the Northern Indian Ocean, with the aim of investigating the weathering response of large Himalayan river basins to orbital and millennial climate forcing. We show that past glaciated episodes of the late Quaternary corresponded to periods of increased physical erosion, associated with... |
| Tipo: Text |
Palavras-chave: Climate change<; /AUTHOR_KEYWORD>; Continental weathering<; /AUTHOR_KEYWORD>; Highlands and floodplains<; /AUTHOR_KEYWORD>; Carbon cycle<; /AUTHOR_KEYWORD>; Himalaya<; /AUTHOR_KEYWORD>. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00632/74434/74154.pdf |
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| Liu, Zhifei; Colin, Christophe; Huang, Wei; Le, Khanh Phon; Tong, Shengqi; Chen, Zhong; Trentesaux, Alain. |
| Results of clay mineralogy, major element geochemistry, and Sr and Nd isotopes in 93 argillaceous samples collected from drainage basins of the Pearl, Red, and Mekong rivers reveal different degrees of chemical weathering in Southeast Asia despite similar climate conditions across these regions. The kaolinite/illite ratio, illite chemistry index, and illite crystallinity can be used as indicators of chemical weathering intensity. These mineralogical proxies combined with the K(2)O/(Na(2)O + CaO) molar ratio, chemical index of alteration (CIA), and weathering trends observed from major element results indicate intensive silicate weathering in the Pearl River basin, moderate to intensive in the Mekong River basin, and moderate in the Red River basin.... |
| Tipo: Text |
Palavras-chave: Clay minerals; Major elements; Chemical weathering; Pearl River; Red River; Mekong River. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00235/34613/32949.pdf |
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| Tachikawa, Kazuyo; Arsouze, Thomas; Bayon, Germain; Bory, Aloys; Colin, Christophe; Dutay, Jean-claude; Frank, Norbert; Giraud, Xavier; Gourlan, Alexandra T.; Jeandel, Catherine; Lacan, Francois; Meynadier, Laure; Montagna, Paolo; Piotrowski, Alexander M.; Plancherel, Yves; Puceat, Emmanuelle; Roy-barman, Matthieu; Waelbroeck, Claire. |
| Neodymium isotopic compositions (143Nd/144Nd or εNd) have been used as a tracer of water masses and lithogenic inputs to the ocean. To further evaluate the faithfulness of this tracer, we have updated a global seawater εNd database and combined it with hydrography parameters (temperature, salinity, nutrients and oxygen concentrations), carbon isotopic ratio and radiocarbon of dissolved inorganic carbon. Archive εNd data are also compiled for leachates, foraminiferal tests, deep-sea corals and fish teeth/debris from the Holocene period (< 10,000 years). At water depths ≥ 1500 m, property-property plots show clear correlations between seawater εNd and the other variables, suggesting that large-scale water mass mixing is a primary control of deepwater εNd... |
| Tipo: Text |
Palavras-chave: Nd isotopes; Water mass tracer; Data compilation; Predicted seawater epsilon(Nd); Seawater-archive comparison. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00376/48768/49165.pdf |
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| Dubois-dauphin, Quentin; Bonneau, Lucile; Colin, Christophe; Montero-serrano, Jean-carlos; Montagna, Paolo; Blamart, Dominique; Hebbeln, Dierk; Van Rooij, David; Pons-branchu, Edwige; Hemsing, Freya; Wefing, Anne-marie; Frank, Norbert. |
| The Nd isotopic composition (εNd) of seawater and cold-water coral (CWC) samples from the Gulf of Cádiz and the Alboran Sea, at a depth of 280-827 m were investigated in order to constrain mid-depth water mass dynamics within the Gulf of Cádiz over the past 40 ka. εNd of glacial and Holocene CWC from the Alboran Sea and the northern Gulf of Cádiz reveals relatively constant values (-8.6 to -9.0 and -9.5 to -10.4, respectively). Such values are similar to those of the surrounding present-day mid-depth waters from the Mediterranean Outflow Water (MOW; εNd ∼ -9.4) and Mediterranean Sea Water (MSW; εNd ∼ -9.9). In contrast, glacial εNd values for CWC collected at thermocline depth (550-827 m) in the southern Gulf of Cádiz display a higher average value... |
| Tipo: Text |
Palavras-chave: Neodymium isotopes; Cold-water corals; Mediterranean outflow water; East Antarctic intermediate water; Mediterranean sea water; Gulf of Cadiz. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00339/45047/44446.pdf |
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| Moreno, Eva; Caroir, Fabien; Fournier, Lea; Fauquembergue, Kelly; Zaragosi, Sébastien; Joussain, Ronan; Colin, Christophe; Blanc-valleron, Marie-madeleine; Baudin, François; De Garidel-thoron, Thibault; Valet, Jean Pierre; Bassinot, Franck. |
| We present here a study based on the Anisotropy of Magnetic Susceptibility (AMS) and magnetic mineralogy carried out on the composite core MD17&18taken from the eastern levee of the active channel of the middle Bengal Fan in the Indian Ocean. Based on C-14 dating, the sedimentary sequence covers 9.8 ka in 39 m of sediment. It therefore records at very high resolution the variations in continental material exported to the ocean by the Ganges-Brahmaputra river system during the Holocene. This sequence was divided into two units according to turbidite activity: Unit 1 from 9.8 to 9.2 ka cal. Representing 39 m of coarse-grained turbidite sequences (coarse silts to fine sands) and extremely high sedimentation rates. Unit 2 of 9.2 ka cal. BP to the present... |
| Tipo: Text |
Palavras-chave: Bengal fan; Holocene; Turbidite activity; Magnetic fabric; Magnetic mineralogy. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00652/76388/77402.pdf |
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| Registros recuperados: 15 | |
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