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Skonieczny, Charlotte; Paillou, P.; Bory, A.; Bayon, Germain; Biscara, L.; Crosta, X.; Eynaud, F.; Malaize, B.; Revel, M.; Aleman, N.; Barusseau, J-p.; Vernet, R.; Lopez, S.; Grousset, F.. |
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... |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00303/41381/40559.pdf |
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Debret, M.; Bout-roumazeilles, V.; Grousset, F.; Desmet, M.; Mcmanus, J. F.; Massei, N.; Sebag, D.; Petit, J. -r.; Copard, Y.; Trentesaux, A.. |
Since the first suggestion of 1500-year cycles in the advance and retreat of glaciers (Denton and Karlen, 1973), many studies have uncovered evidence of repeated climate oscillations of 2500, 1500, and 1000 years. During last glacial period, natural climate cycles of 1500 years appear to be persistent (Bond and Lotti, 1995) and remarkably regular (Mayewski et al., 1997; Rahmstorf, 2003), yet the origin of this pacing during the Holocene remains a mystery (Rahmstorf, 2003), making it one of the outstanding puzzles of climate variability. Solar variability is often considered likely to be responsible for such cyclicities, but the evidence for solar forcing is difficult to evaluate within available data series due to the shortcomings of conventional... |
Tipo: Text |
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Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00233/34454/32880.pdf |
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