1. Geology Department University of Vermont Burlington VT USA
2. Geology Department and School of Natural Resources University of Vermont Burlington VT USA
3. Department of Earth and Environmental Sciences University of Michigan Ann Arbor MI USA
4. US Geological Survey Reston VA USA
5. Department of Earth and Planetary Sciences University of California Berkeley CA USA
6. Center for Accelerator Mass Spectrometry Lawrence Livermore National Laboratory Livermore CA USA
7. SUERC Accelerator Mass Spectrometry Laboratory East Kilbride Scotland UK