The Significance of Calcium Carbonate Oscillations in Eastern Equatorial Atlantic deep-Sea Sediments for the End of the Holocene Warm Interval

Abstract

Distinct correlative calcium carbonate oscillations are evident in two deep-sea cores taken in the Saharan windblown dust zone of the eastern equatorial Atlantic. Using the presence and absence of Globorotalia menardii for stratigraphic control and correlating these cores with radiometrically dated cores from the Caribbean the carbonate oscillations have two distinct periods. Two major oscillations about 117,000 yr and 100,000 yr long, and shorter oscillations averaging about 14,000 yr, occur. The carbonate curves are interpreted to indicate a pronounced increase in wind stress and probable climatic deterioration after the beginning of the last interglacial (post-Eemian). This is also reflected in the carbonate curves for the previous major climatic cycle. If the Holocene warm period is analogous to the Eemian (Barbados Terrace III) then we may expect a pronounced climatic deterioration in the next few thousand years.