Eolian accumulation rates of ODP Leg 121 holes

Temporal changes in the mass accumulation rate of eolian material reflect major climatic shifts in the southern African source region. A significant drop in dust mass flux values occurs near the end of the lower Oligocene.

Younger sediments are characterized by a gradual reduction in dust accumulation rates until the middle Miocene after which values remain consistently low throughout the late Cenozoic, although a slight increase in eolian accumulation rate occurs near 2.5 Ma. This pattern of dust mass flux appears related to the supply of dust-sized particles in the source region and represents a shift in the climatic regime of southern Africa to increasingly more arid conditions throughout the late Cenozoic.