We thank the Ocean Drilling Program and the crew of the JOIDES Resolution for a marvelous cruise. We thank Isabella Raffi for a thoughtful review, which helped to improve the manuscript. Katie Lott deserves a thank you for preparation of the slides used in this study. This research used samples and data provided by the Ocean Drilling Program (ODP). 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 USSAC funds to Kristeen L. McGonigal. Laboratory facilities were provided by NSF grant DPP 94-22893.