Institute for Geology and Paleontology, University of Innsbruck, 6020, Innsbruck, Austria

Institute for Geosciences, University of Kiel, 24098 Kiel, Germany

Invited contribution by M. Sarnthein, recipient of the EGU Milutin Milankovic Medal 2006.

Geologisches Institut, ETH Zuerich, 8092 Zurich, Switzerland

Institute for Geosciences, University of Kiel, 24098 Kiel, Germany

MARUM Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, 28334 Bremen, Germany

College of Ocean and Atmospheric Sciences, Oregon State University, Corvallis OR 97331-5503, USA

Institute for Geosciences, University of Kiel, 24098 Kiel, Germany

Institute for Geosciences, University of Kiel, 24098 Kiel, Germany

Leibniz Laboratory, University of Kiel, 24098 Kiel, Germany

Institute for Geosciences, University of Kiel, 24098 Kiel, Germany