D. J. Kennett1,*, J. P. Kennett2, A. West3, C. Mercer4, S. S. Que Hee5, L. Bement6, T. E. Bunch7, M. Sellers7, W. S. Wolbach81 Department of Anthropology, University of Oregon, Eugene, OR 97403, USA.2 Department of Earth Science, University of California, Santa Barbara, CA 93106, USA.3 GeoScience Consulting, Dewey, AZ 86327, USA.4 National Institute for Materials Science, Tsukuba 305-0047, Japan.5