Late Quaternary climatic events and sea-level changes recorded by turbidite activity, Dakar Canyon, NW Africa

Online Access: Get full text
doi: 10.1016/j.yqres.2009.07.010
Author(s): Pierau, Roberto; Hanebuth, Till J. J.; Krastel, Sebastian; Henrich, Rüdiger
Author Affiliation(s): Primary:
University of Bremen, Center for Marine Environmental Sciences, Bremen, Federal Republic of Germany
Leibniz Institute for Marine Sciences, Federal Republic of Germany
Volume Title: Quaternary Research
Source: Quaternary Research, 73(2), p.385-392. Publisher: Elsevier, New York, NY, United States. ISSN: 0033-5894 CODEN: QRESAV
Note: In English. 48 refs.; illus., incl. 3 tables, sketch map
Summary: The relationship of sea-level changes and short-term climatic changes with turbidite deposition is poorly documented, although the mechanisms of gravity-driven sediment transport in submarine canyons during sea-level changes have been reported from many regions. This study focuses on the activity of the Dakar Canyon off southern Senegal in response to major glacial/interglacial sea-level shifts and variability in the NW-African continental climate. The sedimentary record from the canyon allows us to determine the timing of turbidite events and, on the basis of XRF-scanning element data, we have identified the climate signal at a sub-millennial time scale from the surrounding hemipelagic sediments. Over the late Quaternary the highest frequency in turbidite activity in the Dakar Canyon is confined to major climatic terminations when remobilisation of sediments from the shelf was triggered by the eustatic sea-level rise. However, episodic turbidite events coincide with the timing of Heinrich events in the North Atlantic. During these times continental climate has changed rapidly, with evidence for higher dust supply over NW Africa which has fed turbidity currents. Increased aridity and enhanced wind strength in the southern Saharan-Sahelian zone may have provided a source for this dust. Abstract Copyright (2010) Elsevier, B.V.
Year of Publication: 2010
Research Program: ODP Ocean Drilling Program
Key Words: 03 Geochronology; 24 Surficial Geology, Quaternary Geology; Absolute age; Accelerator mass spectra; Africa; Atlantic Ocean; C-14; Carbon; Cenozoic; Clastic sediments; Continental margin; Cores; Dakar Canyon; Dust; East Atlantic; Foraminifera; Heinrich events; Invertebrata; Isotope ratios; Isotopes; Leg 108; Marine environment; Marine sediments; Mass spectra; Microfossils; North Africa; North Atlantic; O-18/O-16; ODP Site 658; Ocean Drilling Program; Oxygen; Paleoclimatology; Protista; Quaternary; Radioactive isotopes; Sea-level changes; Sediment transport; Sediments; Spectra; Stable isotopes; Submarine environment; Transport; Turbidite; Upper Quaternary; West Africa; X-ray fluorescence spectra
Coordinates: N132000 N133330 W0185345 W0190630
Record ID: 2010082303
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands