Timing and stepwise transitions of the African Humid Period from geochemical proxies in the Nile deep-sea fan sediments
PIVOT, Sébastien
Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
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Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
PIVOT, Sébastien
Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
DAVTIAN, Nina
Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
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Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement [CEREGE]
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Este ítem está publicado en
Quaternary Science Reviews. 2020-01, vol. 228, p. 106071
Resumen en inglés
Large fluvial systems, such as the Nile River, allow a basin-scale integrated view of climatological and environmental changes. In this study, we reconstructed the Nile discharge history for the last 20 ka using molecular ...Leer más >
Large fluvial systems, such as the Nile River, allow a basin-scale integrated view of climatological and environmental changes. In this study, we reconstructed the Nile discharge history for the last 20 ka using molecular ratios of glycerol dialkyl glycerol tetraethers (GDGTs) and neodymium (Nd) radiogenic isotopes. By characterizing both the organic and inorganic fractions, we assessed the relevance of the GDGT-based proxies in deltaic environments as tracers of terrigenous origin. A large increase in Nile discharge is documented from 14.8 to 8.4 ka BP reflecting enhanced physical erosion and transport processes from the Ethiopian Traps. We confirmed the primary control of insolation on precipitation on North East Africa through the last 20 ka. The centennial time resolution reached on the sedimentary sequence revealed a step-wise onset and termination of the African Humid Period (AHP) starting at 14.8 ka and ending at 8.4 ka BP, respectively. Our centennial-millennial records allowed furthermore pinpointing the abrupt periods of arid conditions corresponding to the Younger Dryas. These data illustrate the linkage between low and high latitude hydrological variability.< Leer menos
Palabras clave en inglés
Nile river
GDGT-indices
African Humid Period
Clastic εNd
Centros de investigación