We thank Lorraine Albrecht (mass spectrometry; Waterloo), Regina Surberg (ICP-AES; Kiel), and Dieter Garbe-Schönberg (ICP-MS; Kiel) for help with the analyses and the Shipboard Scientific Party of ODP Leg 186 for discussion. The manuscript benefitted from suggestions and criticisms by Jon Martin and Jeff Ryan, for which we are most grateful. This research used samples and data provided by the Ocean Drilling Program (ODP). The ODP is sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc. Funding for this research was provided by the Alexander-von-Humboldt Stiftung (to A.K.) and DAAD (Deutscher Akademischer Austauchdienst) and DFG (Deutsche Forschungsgemeinschaft; DE 819/1-1) fellowships (to A.D.).