1. Department of Earth Sciences, Dartmouth College, Hanover, NH 03755
2. Department of Geology, University of Illinois at Urbana–Champaign, Urbana, IL 61801
3. Department of Earth & Environmental Sciences, Lehigh University, Bethlehem, PA 18015
4. Department of Earth & Planetary Science, University of California, Berkeley, CA 94720
5. Noble Gas Thermochronology Laboratory, Berkeley Geochronology Center, Berkeley, CA 94709