This research used samples provided by the Ocean Drilling Program (ODP). ODP is sponsored by the U.S. National Science Foundation (NFSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc. B. Monteleone acknowledges support from ODP while participating in Leg 180. We thank Tim Swindle for comments on an earlier draft of this manuscript and Joe Wooden and Harold Persing for assistance with SHRIMP analyses at Stanford University. We are grateful to Ian McDougall and Hugh Davies for their careful reviews and comments that improved the paper. This study was funded by a grant from USSSP 190-F000942.