1. Holocene hydrological changes of the Rhone River (NW Mediterranean) as recorded in the marine mud belt.
- Author
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Bassetti, M. A., Berné, S., Sicre, M. A., Dennielou, B., Alonso, Y., Buscail, R., Jalali, B., Hebert, B., and Menniti, C.
- Abstract
Expanded marine Holocene archives are relatively scarce in the Mediterranean Sea because most of the sediments were trapped in catchment areas during this period. Mud belts are most suitable targets to access expanded Holocene records. These sedimentary bodies represent excellent archives for the study of sea-land interactions and notably the impact of the hydrological activity on sediment accumulation. We retrieved a 7.2 m-long sediment core from the Rhone mud belt in the Gulf of Lions in an area where the average accumulation rate is of ca. 0.70 m/1000 years. This core thus provides a continuous and high-resolution record of the last 10 ka cal BP. A multi-proxy dataset (XRF-core scan,
14 C dates, grain size and organic matter analysis) combined with seismic stratigraphic analysis was used to document decadal to centennial changes of the Rhone hydrological activity. Our results show that 1) the Early Holocene was characterized by high sediment delivery likely indicative of local intense (but short duration) rainfall events , 2) important sediment delivery around 7 ka cal BP roughly presumably related to increased river flux, 3) a progressive increase of continental/marine input during the Mid-Holocene despite increased distance from river outlets due to sea-level rise possibly related to higher atmospheric humidity caused by the southward migration of the storm tracks in the North Atlantic, 4) multi-decadal to centennial humid events in the Late Holocene. Some of these events correspond to the cold periods identified in the North Atlantic (Little Ice Age, LIA; Dark Age) and also coincide with time intervals of major floods a in the Northern Alps. Other humid events are also observed during relatively warm periods (Roman Humid Period and Medieval Climate Anomaly). [ABSTRACT FROM AUTHOR]- Published
- 2016
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