Consulta: subjectFacets:"Holocène"
Registros recuperados: 7
Data/hora: 03/06/2024 01:18:23

Traceurs micropaléontologiques (dinokystes et coccolithes) de l'hydrographie actuelle et holocène aux moyennes et hautes latitudes de l'Atlantique Nord
Provedor de dados: 5
Autores: Solignac, Sandrine.
Devant le problème du réchauffement planétaire, il est indispensable d'approfondir notre compréhension des mécanismes et des rétroactions qui régulent le climat pour pouvoir prédire les conséquences de tels changements. L'étude des climats passés permet de mettre en évidence la façon dont les événements climatiques s'encharnent. En particulier, étudier des périodes plus chaudes que l'actuelle permet de mieux comprendre ce vers quoi nous semblons nous diriger. C'est dans cette.optique que de nombreuses recherches sont menées sur l'évolution du climat au cours de la présente période interglaciaire, 1'Holocène. Notamment, bon nombre de ces études portent sur le milieu océanique, celui-ci étant responsable d'une grande partie des transferts de chaleur à la...
Tipo: Text
Palavras-chave: Atlantique Nord; Holocène; Circulation océamque; Masse d'eau; Dinokyste; Coccolithe; Distribution; Fonction de transfert.
Ano: 2008
URL: https://archimer.ifremer.fr/doc/00505/61697/65665.pdf

Holocene coastal changes and infilling of the La Perroche marsh (French Atlantic coast)
Provedor de dados: 5
Autores: Clave, B; Masse, L; Carbonel, P; Tastet, Jp.
The La Perroche marsh is a small Holocene marsh on the south-western coast of the Oleron island (Bay of Biscay, France) presently occupied by a freshwater swamp and separated from the ocean by a continuous sand dune ridge. The study of its infill shows first basal conglomeratic deposits with calcareous pebbles on a Cenomanian rough substrate. The Holocene infill since 6000 years BP begins with a very fast sedimentation of sands. Then, the sedimentation becomes finer, with lagoonal to freshwater influences recorded by ostracods. The distribution of these deposits inside the marsh is asymmetric, with a thick sandy-gravely layer in the eastern part and a succession of sands, clays and organic layers in the western part. Communication with the sea is episodic,...
Tipo: Text
Palavras-chave: Changements côtiers; Marais maritime; Holocène; Ostracodes; Sédiments; Coastal changes; Coastal salt marsh; Holocene; Ostracods; Sediments.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00322/43349/42877.pdf

Morpho-sedimentary evidence of Holocene coastal changes near the mouth of the Gironde and on the Medoc Peninsula, SW France
Provedor de dados: 5
Autores: Pontee, Ni; Tastet, Jp; Masse, L.
The Medoc Peninsula is a triangular area of land between the Atlantic Ocean on the west and the Gironde estuary on the east. The Gironde, orientated SE-NW, is the largest estuary in France. On the Medoc Peninsula Holocene sediments cover a substratum of Tertiary limestones and Plio-Pleistocene fluvial terraces. The Gironde originated as an incised valley during the Weichselian glacio-eustatic fall (100 000-18 000 B.P.) and has acted as a sink for fine sediment throughout the Holocene sea level rise (SLR) (18 000 B.P. onwards). Conversely, the Atlantic littoral zone, characterised by sandy beaches and dunes, has been subjected to erosion throughout the Holocene transgression. The incised valley of the present Gironde was inundated by the sea approximately...
Tipo: Text
Palavras-chave: Holocène; Changement côtier; Marais estuarien; Dune éolienne; Chenier; Holocene; Coastal change; Salt marsh; Aeolian dune; Chenier.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00326/43683/43191.pdf

Epi-bathyal ostracod assemblage in Holocene Rhone deltaic sediments (Gulf of Lions, NW Mediterranean) and their palaeoecological implications
Provedor de dados: 5
Autores: Fanget, Anne-sophie; Bassetti, Maria Angela; Berne, Serge; Arnaud, Mireille.
Since the Last Glacial Maximum, the Rhone River, which is the most important source of freshwater and sediment to the western Mediterranean Sea, migrated in a north-westward direction during the rapid Deglacial and Early Holocene sea-level rise. During the phase of global high sea-level (Middle and Late Holocene), an overall eastward migration of the Rhone outlet, under natural and/or human influence, is recorded through several sediment accumulations confined along the inner shelf in the form of deltaic lobes. These lobes that make up the whole Rhone subaqueous delta represent very expanded sedimentary archives of the Rhone Holocene history. In this paper, using three long piston cores retrieved from the most recent Bras de Fer (RHS-KS55) and Roustan...
Tipo: Text
Palavras-chave: Ostracodes; Delta sous-marin; Paléoécologie; Holocène; Méditerranée occidentale; Ostracoda; Subaqueous delta; Palaeoecology; Holocene; Western Mediterranean.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00217/32810/31253.pdf

Dynamique sédimentaire et évolution holocène d'un système macrotidal semi-fermé : l'exemple de la rade de Brest
Provedor de dados: 5
Autores: Gregoire, Gwendoline.
The bay of Brest is a tide-dominated, semi-enclosed coastal basin, which is connected with two rivers (Aulne and Elorn). Its jagged shoreline and seabed morphology constitute an ideal setting to understand sedimentary transfer at the land-sea interface. In this aim, this study is divided in two different time scale. The first (a) focuses on the present-day sedimentary bedload dynamic and the second (b) on the reconstruction of the Holocene infilling, during the last marine transgression. (a) A analyse combining a sedimentology approach and numerical has highlighted the major control of the tidal currents. Swells and rivers have a minor impact, because the inherited morphology accentuates and promotes tidal currents. There are responsible of a shelly sandy...
Tipo: Text
Palavras-chave: Dynamique sédimentaire; Holocène; Paléo-vallée; Estuaire; Système côtier; Rade de Brest; Carottages; Sismique-réflexion; Imagerie; Bathymétrie; Seismic reflection; Coastal system; Bay of Brest; Coring; Paleo-valley; Estuary; Sedimentary dynamic; Backscatter imagery; Bathymetry.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00498/60920/64282.pdf

The experimental analysis on the Late Quaternary deposits of the Black Sea
Provedor de dados: 5
Autores: Tekiroglu, Selin Eda; Ediger, Vedat; Yemenicioglu, Semal; Kapur, Selim; Akca, Erhan.
Holocene sediments taken from the south-eastern and western Black Sea have been investigated in relation to their geochemical, sedimentological and mineralogical characteristics. Their textures are characterized by their low amount of sand, upward-increasing silt and downward-increasing clay contents. While the terrigenous materials transported from Anatolian volcanic-based sources and European alluvial sediments form the shore deposits, the deep-sea sediments mainly consist of the marine biological production. The highest amount of organic carbon was deposited following the formation of anoxic conditions at the bottom until the beginning of the still continuing carbonate-rich coccolith (Emiliania huxleyi) deposition. The high metal concentrations are...
Tipo: Text
Palavras-chave: Mer Noire; Holocène; Sapropel; Coccolithes; Black Sea; Holocene; Sapropel; Coccolith.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00323/43369/42841.pdf

Les reconstitutions paléo-hydrographiques de surface dans le Golfe de Gascogne au cours de l'Holocène
Provedor de dados: 5
Autores: Zumaque, Jéna.
La carotte MD95-2002, prélevée dans le Golfe de Gascogne (47°27'N; 08 °32'W, 2174m) a fait l'objet d'analyses micropaléontologiques afin de « documenter » les changements dans les conditions palée-hydrographiques de surface et de la colonne d'eau sous-jacente au cours de l'Holocène dans l'Atlantique nord-est. Les reconstructions quantitatives basées sur les assemblages de kystes de dinoflagellés (dinokystes) et les compositions isotopiques de foraminifères planctoniques ont permis de mettre en évidence des tendances à long terme auxquelles se superpose une importante variabilité climatique. Cette dernière se traduit principalement par des fortes variations des températures d'eau de surface (Sea-Surface Temperatures - SSTs) à l'Holocène inférieur, avec des...
Tipo: Text
Palavras-chave: Holocène; Atlantique nord-est; Golfe de Gascogne; Conditions paléohydrographiques de surface; Dinokystes; Foraminifères planctoniques; Compositions isotopique; Oscillation Nord Atlantique.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00499/61040/64447.pdf