We thank W.H. Berger for valuable suggestions and discussions during the development of the study. Comments by the reviewers L. Dupont and R. Gersonde helped to improve the manuscript. We also thank the ODP officers, crew, shipboard technicians and scientific party of Leg 175, without whom this work would not have been possible. K.G. Johnson assisted with the statistical analysis. The analytical work done at Bremen University was funded by the Schwerpunkt Program DSDP/ODP of the Deutsche Forschungsgemeinschaft (grant We 992/26). We acknowledge financial support from the JOI/USSSP postcruise grants 175-F000828 (to C.B.L.), 175-F000630 (to M.E.P.), grant NSC 88-2611-M-110-010-ODP (to H.-H.L), and a fellowship from the Basque Country Government (to M.E.P).