Climate induced sediment dynamics in a canyon system offshore the hyperarid Western Sahara (Mauritania): the Timiris Canyon

• Rüdiger Henrich ^[1] ; Yvonne Cherubini ^[1] ; Helge Meggers ^[1]
  1. [1] University of Bremen

     University of Bremen

     Kreisfreie Stadt Bremen, Alemania

     
• Localización: Geotemas (Madrid), ISSN 1576-5172, Nº. 11, 2010 (Ejemplar dedicado a: Deep-Water Circulation: Processes & Products. International Congress. Baitona, Pontevedra, Spain. 16 & 17 June 2010), págs. 67-69
• Idioma: inglés
• Enlaces
  • Texto Completo Ejemplar
• Resumen

  • A major outcome from studying the sedimentary archives of the Timiris Canyon off Mauritania is that climate shifts in the Saharan hinterland not only influenced offshore pelagic sedimentation processes but also controlled turbidite activity in the canyon. Sediment supply to the slope, predominantly by dust and remobilised eolian sands, was greatest during hyperarid glacial and deglacial periods and due to overall increased Trade wind strengths upwelling induced pelagic productivity attained highest magnitudes. Turbidite activity in the canyon immediately responded to these shifts. During high-glacial and early deglacial time intervals the tributary gullies on the uppermost slope were rapidly and repetitively filled, subsequently turbidity currents were released and large turbulent flows passed through the lower Timiris Canyon leading to over-spills on its levees. During successive sea level rises in MIS 3 sediments from huge aeolian dune fields that had expanded close to the shelf edge during glacial exposure were remobilized and transferred though the canyon. During the Holocene no turbidite activity is registered in the Lower Timiris Canyon, whereas a core from a widened area in the Upper Timiris Canyon reveals an interesting climate controlled 900-year cyclicity of turbidite events.