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Título:
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Climate-driven changes in sedimentation rate influence phosphorus burial along continental margins of the northwestern Mediterranean
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Autores:
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Cortina, Aleix ;
Filippelli, Gabriel ;
Ochoa, Diana ;
Javier Sierro, Francisco ;
Flores, José-Abel ;
Grimalt, Joan O.
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Tipo de documento:
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texto impreso
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Editorial:
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Elsevier, 2018-11-30T23:41:32Z
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Nota general:
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info:eu-repo/semantics/restrictedAccess
https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es
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Idiomas:
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Inglés
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Palabras clave:
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Editados por otras instituciones
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Artículos
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Artículos en revistas indizadas
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Resumen:
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The burial of phosphorus (P) in continental margin sediments is a critical component of the marine reactive P budget, and thus an important factor in marine biological productivity. We determined downcore records of P from a site drilled on the upper slope of the Gulf of Lions (PRGL 1), northwestern Mediterranean Sea. Changes in total P content were monitored from Marine Isotope Stage (MIS) 6 to MIS 11. In addition, in two selected intervals (248-277 ka and 306-342 ka) the total P record was expanded by adding detailed geochemical analyses of the various P fractions, including oxyhydroxide-associated P, authigenic P, detrital P and organic P. Increased sedimentation rates during glacials owing to seaward migration of the Rhone's mouth, enhanced the burial of reactive P (oxyhydroxide-associated + authigenic + organic) phases by decreasing its time at the reactive sediment/water interface, in turn resulting in increasing proportion of authigenic to detrital phosphorus. The inverse was found for interglacial stages. The effects of glacial/interglacial variation in sedimentation rate over P geochemistry resulted in changes in sediment-water interface oxygenation, as well as in the efficiency of P burial, as shown by (C:P)(org) and C-org:P-react proxies respectively. Two events of high P deposition associated with authigenic (P-aut1) formation, at 335 (P-aut2) and 275 ka (P0052), were associated with periods of rapid disintegration of North Atlantic ice sheets leading to Ice Rafted Debris (IRD) deposition. These high P deposition events appear to be linked to short warm periods that followed cold episodes. Enhanced continental runoff owing to more humid conditions during short warm episodes could play a critical role for enhanced biogenic productivity and posterior authigenic P accumulation.
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En línea:
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http://doi.org/10.1016/j.palaeo.2018.03.010
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