Climate and sea level controlled sedimentation processes in two submarine canyons off NW-Africa [Elektronische Ressource] / vorgelegt von Roberto Pierau

Climate and sea level controlled sedimentation processes in two submarine canyons off NW-Africa Dissertation zur Erlangung des Doktorgrades am Fachbereich Geowissenschaften der Universität Bremen vorgelegt von Roberto Pierau Bremen, September 2008 Tag des Kolloquiums: 14.11.2008 Gutachter: Prof. Dr. Rüdiger Henrich Prof. Dr. Sebastian Krastel Prüfer: Prof. Dr. Heinrich Villinger Prof. Dr. Hans-Joachim Kuss Abstract This study focuses on the trigger mechanisms of gravity-driven sediment transport in two submarine canyons at the passive continental margin off NW-Africa during the past 240 kyr. The sedimentary records allow to determine the turbidite emplacement times based on high resolution age models. The sediment textures of the turbidites were studied by using X-ray radiographies. The sedimentary properties like the terrigenous silt size distribution and XRF-core scanning element data allow to identify the variability of the aeolian dust input in the hemipelagic sediments. These variations can be used to reconstruct the climatic conditions in the hinterland which strongly influence the sediment supply on the shelf. In addition a clay mineral assemblage was used to reconstruct the fluvial input of the West-African rivers.