We thank reviewers V. Salters, A. Saunders, and P. Quilty for their constructive comments and G. Xu for preparation of geochemical figures. This synthesis is based on research accomplished by an international team of shipboard and shore-based scientists. None of this research could have been accomplished without the dedicated efforts of the ODP Operations Manager Mike Storms, SEDCO Drilling Superintendent Scott Pedersen, Captain Anthony Ribbens, and their respective ODP and SEDCO shipboard crews. This research used samples and data provided by the Ocean Drilling Program (ODP). The ODP is sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc. Funding for much of the Leg 183 research was provided by the U.S. Science Support Program (USSSP). University of Texas Institute for Geophysics Contribution 1606.