This research was supported by JOI/USSAC and by National Science Foundation grants. We thank the Ocean Drilling Program and the Leg 167 Scientific Party. Other individuals who have contributed to the development of this manuscript include N. Pisias, C. Heusser, and E. Stock. We thank L. Dupont and A. Mix for reviewing the manuscript. Oregon State University curating facilities are supported by NSF grant OCE94-02298.