Characteristics and distribution of Neogene turbidites at Site 657 (Leg 108, Cap Blanc continental rise, northwest Africa): variations in turbidite source and continental climate

Abstract

The stratigraphic distribution of these turbidites indicates five periods during which climatic conditions and material sources change. Turbidite occurrence prior to 6.2Ma (late Miocene) is sparse. The sedimentary characteristics of turbidites are mainly controlled by sediment source and climate. The frequency must be influenced by sea-level variations, by cyclic processes of climatic origin, and possibly by variations in the continental slope morphology. Clay mineral assemblages suggest a south Saharan source of terrigenous material during the late Miocene and the Pliocene and a northwest Saharan source during the Pleistocene. -from Authors