The authors would like to thank Toshihiko Kanazawa, William W. Sager, Carlota Escutia, and the Shipboard Party and crew of JOIDES Resolution Leg 191 for their support and encouragement. This research used samples and data provided by the Ocean Drilling Program (ODP). We would also like to thank reviewers J. Barron and R. Laws and ODP editor Lorri Peters for their keen eyes, invaluable suggestions, and much appreciated advice. ODP is sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc. In particular, this research was funded by a grant from the JOI/U.S. Science Support Program.