Consulta: creatorFacets:"Hodell, David"
Registros recuperados: 2
Data/hora: 26/07/2024 22:10:32

Carbon isotope offsets between benthic foraminifer species of the genus Cibicides (Cibicidoides) in the glacial sub-Antarctic Atlantic
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Gottschalk, Julia; Riveiros, Natalia Vazquez; Waelbroeck, Claire; Skinner, Luke C.; Michel, Elisabeth; Duplessy, Jean-claude; Hodell, David; Mackensen, Andreas.
Epibenthic foraminifer delta C-13 measurements are valuable for reconstructing past bottom water dissolved inorganic carbon d13C (delta C-13(DIC)), which are used to infer global ocean circulation patterns. Epibenthic delta C-13, however, may also reflect the influence of C-13-depleted phytodetritus, microhabitat changes, and/or variations in carbonate ion concentrations. Here we compare the delta C-13 of two benthic foraminifer species, Cibicides kullenbergi and Cibicides wuellerstorfi, and their morphotypes, in three sub-Antarctic Atlantic sediment cores over several glacial-interglacial transitions. These species are commonly assumed to be epibenthic, living above or directly below the sediment-water interface. While this might be consistent with the...
Tipo: Text
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00421/53207/54927.pdf

Response of Iberian Margin sediments to orbital and suborbital forcing over the past 420 ka
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Hodell, David; Crowhurst, Simon; Skinner, Luke; Tzedakis, Polychronis C.; Margari, Vasiliki; Channell, James E. T.; Kamenov, George; Maclachlan, Suzanne; Rothwell, Guy.
Here we report 420 kyr long records of sediment geochemical and color variations from the southwestern Iberian Margin. We synchronized the Iberian Margin sediment record to Antarctic ice cores and speleothem records on millennial time scales and investigated the phase responses relative to orbital forcing of multiple proxy records available from these cores. Iberian Margin sediments contain strong precession power. Sediment "redness" (a* and 570-560 nm) and the ratio of long-chain alcohols to n-alkanes (C26OH/(C26OH+C-29)) are highly coherent and in-phase with precession. Redder layers and more oxidizing conditions (low alcohol ratio) occur near precession minima (summer insolation maxima). We suggest these proxies respond rapidly to low-latitude...
Tipo: Text
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00262/37304/35702.pdf