L3AB - Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux, OASU - Observatoire aquitain des sciences de l'univers, LAB - Laboratoire d'Astrophysique de Bordeaux [Pessac], UB - Université de Bordeaux
Abstract : The Sahara experienced several humid episodes during the late Quaternary, associated with the development of vast fluvial networks and enhanced freshwater delivery to the surrounding ocean margins. In particular, marine sediment records off Western Sahara indicate deposition of river-borne material at those times, implying sustained fluvial discharges along the West African margin. Today, however, no major river exists in this area; therefore, the origin of these sediments remains unclear. Here, using orbital radar satellite imagery, we present geomorphological data that reveal the existence of a large buried paleodrainage network on the Mauritanian coast. On the basis of evidence from the literature, we propose that reactivation of this major paleoriver during past humid periods contributed to the delivery of sediments to the Tropical Atlantic margin. This finding provides new insights for the interpretation of terrigenous sediment records off Western Africa, with important implications for our understanding of the paleohydrological history of the Sahara.
https://hal-univ-perp.archives-ouvertes.fr/hal-01250419
Contributeur : Olivier Savoyat
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Soumis le : lundi 4 janvier 2016 - 17:26:35
Dernière modification le : lundi 10 décembre 2018 - 01:23:51
C. Skonieczny, Philippe Paillou, A. Bory, G. Bayon, L. Biscara, et al.. African humid periods triggered the reactivation of a large river system in Western Sahara. Nature Communications, Nature Publishing Group, 2015, 6, pp.8751 〈10.1038/ncomms9751〉. 〈hal-01250419〉
