I wish to thank the Shipboard Scientific Party of Leg 162, especially Bill Austin and Maureen Raymo, for providing the samples. For technical assistance I thank Amelie Winkler, Tjard Kusche, Albert von Doetinchem, and Jutta Heinze (all from Kiel). Silvia Spezzaferri and Christian Betzler kindly reviewed the manuscript. Financial support was given by the Deutsche Forschungsgemeinschaft Bonn.