This project was supported by a grant to Marsaglia from the National Science Foundation and Joint Oceanographic Institutions administered by the Texas A&M Research Foundation. Petrographic data were collected for this study as part of research for an M.S. thesis by Latter (Sites 976-979 and beach sands) and an undergraduate research project by Cline (Site 974) who was supported by the AMP (Alliance for Minority Participation) program at the University of Texas El Paso. We thank Menchu Comas and an anonymous reviewer for their helpful comments.