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| Registros recuperados: 49 | |
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| Snow, Tasha. |
| The Arctic and North Atlantic underwent significant climactic changes since the Last Glacial Maximum (25,000 years before present (1950 AD); ka BP), but offsets in the timing of events between the two regions are poorly constrained due to age model uncertainties that arise from changing radiocarbon reservoir ages. Here, we use a relatively high-resolution, multi-proxy stable isotope and sedimentologic dataset from Eastern Fram Strait (ODP Leg 162 Site 986) marine sediments to constrain the timing of Svalbard/Barents Sea Ice Sheet decay and infer deglacial reservoir ages over the last 30 ka. We use magnetic susceptibility, inorganic and organic carbon, foraminiferal assemblage counts, planktonic foraminiferal isotopes, and iceberg-rafted debris proxies to... |
| Tipo: Text |
Palavras-chave: Paleoceanography; Meltwater; Isotopes; Foraminifera; Fram Strait; Reservoir age. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00499/61045/64452.pdf |
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| Sikes, El; Sicre, Ma. |
| This study assesses the relationship to salinity and temperature of the levels of the tetra-unsaturated 37-carbon methyl alkenone (C-37:4) in the surface ocean. U-37(K'), a measure of the relative abundances of the C-37:2 and the C-37:3 alkenones, has a well constrained linear relationship to temperature in the open ocean [Prahl and Wakeham, 1987] and is a well-established technique for estimating past sea surface temperatures in the sediments (e. g. [Muller et al., 1998]). Unlike the di- and tri-unsaturated C-37 alkenones, the temperature response of the tetra-unsaturated C-37 alkenone is less certain [Sikes et al., 1997], and recent work has suggested a relationship to salinity instead [Rosell-Mele, 1998; Schulz et al., 2000]. Our study examined 106... |
| Tipo: Text |
Palavras-chave: Alkenones; Paleosalinity; Marine organic geochemistry; Organic geochemistry; Paleoceanography; Organic marine chemistry. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00223/33414/31886.pdf |
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| Andersson, C; Risebrobakken, B; Jansen, E; Dahl, So. |
| Late Holocene sea surface ocean conditions of the eastern Norwegian Sea (Voring Plateau) are inferred from planktic stable isotopes and planktic foraminiferal assemblage changes in cores JM97-948/2A and MD95-2011 (66.97degreesN, 7.64degreesE). Strong covariance between the planktic stable oxygen isotopic record and abundance changes of N. pachyderma (sin) show that major changes in surface ocean conditions are reflected both in the geochemical composition of the foraminiferal tests as well as in the composition of the foraminiferal fauna. Surface ocean conditions warmer than present were common during the past 3000 years. During the so-called Medieval Warm Period, surface conditions were highly variable with marked changes in sea surface temperature. The... |
| Tipo: Text |
Palavras-chave: Paleoceanography; Stable isotope; Holocene; Micropaleontology. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00224/33495/31954.pdf |
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| Chang, Yp; Chang, Cc; Wang, Lw; Chen, Mt; Wang, Ch; Yu, Ef. |
| A high-resolution (similar to 4 - 5cm/kyr) giant piston core record (MD962085) retrieved during an IMAGES II - NAUSICAA cruise from the continental slope of the southeast Atlantic Ocean reveal striking variations in planktonic foraminifer faunal abundances and sea-surface temperatures (SST) during the past 400,000 years. The location and high-quality sedimentary record of the core provide a good opportunity to assess changes in the intensity and position of the Benguela Current System and the Subtropical Convergence, two key features of the ocean-climate system in the south Atlantic. This record can be also used to evaluate the possible influence of Agulhas Current from the throughflow of the Indian Ocean into the South Atlantic. The planktonic foraminifer... |
| Tipo: Text |
Palavras-chave: Paleoceanography; Late Quaternary; Micropaleontology; South Atlantic. |
| Ano: 1999 |
URL: https://archimer.ifremer.fr/doc/00239/35070/34563.pdf |
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| Loncke, L.; Roest, Walter; Klingelhoefer, Frauke; Basile, C.; Graindorge, David; Heuret, A.; Marcaillou, B.; Museur, Thomas; Fanget, Anne-sophie; Mercier De Lépinay, M.. |
| Numerous submarine plateaus form highstanding bathymetric highs at continent to ocean transitions. Due to their proximity to continents, they have been frequently labelled “marginal plateaus”, although this term has not been clearly defined or associated with a specific geology or geodynamic process. Until now, these elevations have been interpreted as submerged thinned continental fragments detached from continents, basaltic buildups formed by hotspots, volcanic margins or oceanic plateaus. Many of these plateaus formed at transform margins connecting oceanic basins of contrasted ages. We propose for the first time to define and review a class of marginal plateaus related to a specific tectonic setting: “Transform Marginal Plateaus” (TMPs). Based on a... |
| Tipo: Text |
Palavras-chave: Transform marginal plateau; Transform margin; Volcanic margin; Large Igneous Province; Continental breakup; Paleoceanography; Land bridge; Gateway. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00512/62407/66663.pdf |
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| Rogerson, M.; Cacho, I.; Jimenez-espejo, F.; Reguera, M. I.; Sierro, F. J.; Martinez-ruiz, F.; Frigola, J.; Canals, M.. |
| The eastern Mediterranean sapropels are among the most intensively investigated phenomena in the paleoceanographic record, but relatively little has been written regarding the origin of the equivalent of the sapropels in the western Mediterranean, the organic-rich layers (ORLs). ORLs are recognized as sediment layers containing enhanced total organic carbon that extend throughout the deep basins of the western Mediterranean and are associated with enhanced total barium concentration and a reduced diversity (dysoxic but not anoxic) benthic foraminiferal assemblage. Consequently, it has been suggested that ORLs represent periods of enhanced productivity coupled with reduced deep ventilation, presumably related to increased continental runoff, in close... |
| Tipo: Text |
Palavras-chave: Sapropel; Mediterranean; Sea level; Paleoceanography; Circulation. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34825/33303.pdf |
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| ORTLIEB,LUC; ESCRIBANO,RUBEN; FOLLEGATI,RENZO; ZUÑIGA,OSCAR; KONG,ISMAEL; RODRIGUEZ,LUIS; VALDES,JORGE; GUZMAN,NURY; IRATCHET,PAOLA. |
| Atmosphere-ocean interactions are particularly strong along the Chile-Peru coast and largely account for the extreme aridity of the Atacama Desert. Near the center of the driest part of this coastal desert, we found that the embayment Bahía Mejillones constitutes an unusually favorable setting for the formation and subsequent preservation of a sedimentary record of the successive oceanographic conditions of the last few thousand years. This work deals with relative abundance of various bio-indicators, including fish scales, foraminifers and phytoplankton, with a centimetre-scale resolution, in several gravity cores taken from 80 to 120 m depth, in a low-oxygen environment. We use this information to document ocean-climate changes at decadal to centennial... |
| Tipo: Journal article |
Palavras-chave: Bioindicators; Paleoceanography; Paleoclimatology; Northern-Chile; Low-oxygen sediments. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2000000200002 |
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| Bergue,Cristianini T.; Govindan,Abiraman. |
| The Eocene-Pliocene deep sea ostracodes from the ODP site 744A (Kerguelen Plateau) are herein studied under the taxonomic and paleoecologic aspects. 28 species are identified, being the genera Krithe, Cytherella and Dutoitella the most diversified. A faunal threshold was recorded in the Early Oligocene, which is tentatively explained under the knowledge of the paleoceanographical studies carried out not only in the Kerguelen Plateau but also in adjacent areas. The faunal turnover and variations in both richness and abundance possibly reflect the inception of psychrosphere and the influence of hydrological changes in the preservation of carapaces. Moreover, the influence of those changes on carbonate preservation is discussed as the cause of faunal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cenozoic; Ostracodes; Paleoceanography; Paleozoogeography. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652010000300021 |
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| LOPES,RENATO P.; DILLENBURG,SERGIO R.; SCHULTZ,CESAR L.; FERIGOLO,JORGE; RIBEIRO,ANA MARIA; PEREIRA,JAMIL C.; HOLANDA,ELIZETE C.; PITANA,VANESSA G.; KERBER,LEONARDO. |
| The coastal plain of the state of Rio Grande do Sul, in southern Brazil, includes four barrier-lagoon depositional systems formed by successive Quaternary sea-level highstands that were correlated to marine isotope stages (MIS) 11, 9, 5 and 1, despite the scarcity of absolute ages. This study describes a sea-level highstand older than MIS 5, based on the stratigraphy, ages and fossils of the shallow marine facies found in coastal barrier (Barrier II). This facies outcrops along the banks of Chuí Creek, it is composed of fine, well-sorted quartz sand and contains ichnofossils Ophiomorpha nodosa and Rosseliasp., and molluscan shells. The sedimentary record indicates coastal aggradation followed by sea-level fall and progradation of the coastline.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Barrier II; Chuí Creek; MIS 7; Pleistocene; Paleoceanography. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000401573 |
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| Registros recuperados: 49 | |
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