1. Radiocarbon Laboratory, Department of Anthropology, Institute of Geophysics and Planetary Physics, University of California, Riverside, CA 92521, USA
2. Center for Accelerator Mass Spectrometry, University of California, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
3. Applied Paleoscience, 648 Saint Street, Richland, WA 99352, USA