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. Sample preparation was undertaken by Geoscience Australia (Canberra). Detailed information on stratigraphy was provided by Dr. P.E. O'Brien of that institution. Drs. R.A. Askin and J.H. Wrenn provided constructive comments on a draft. E.M. Truswell acknowledges facilities provided by the Department of Geology, Australian National University, where she is a Visiting Fellow.