The present data set is based on samples provided by the Ocean Drilling Program (ODP). ODP is sponsored by the U.S. National Science Foundation and participating countries under the management of Joint Oceanographic Institutions. We thank Lorri Peters for editorial comments. We also acknowledge the technical assistance of U. Bock and R. Cordelair. This study was supported by the Deutsche Forschungsgemeinschaft (DFG grant Ge516/6).