We thank the crew, technicians, and shipboard scientists who sailed aboard the JOIDES Resolution during Leg 204 for their assistance with sample acquisition. Julia and Sarah Slaughter assisted with sample preparation, and Nandini Basu assisted with XRD analyses. This project utilized samples provided by the Ocean Drilling Program (ODP). The ODP was sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc. Funding to Underwood was provided by the National Science Foundation (OCE-0001768). Achim Kopf kindly reviewed the manuscript.