1. U.S. Geological Survey, Crustal Geophysics and Geochemistry
Science Center, MS964D, Denver Federal Center, Denver, Colorado 80225, United States
2. U.S. Geological Survey, Colorado Water Science Center, Denver
Federal Center, Denver, Colorado 80225, United States
3. PerkinElmer, Incorporated, 75 Nicholson Lane, San Jose, California 95132, United States
4. U.S. Geological Survey, Geology, Minerals, Energy, and Geophysics Science Center, 345 Middlefield Road, Menlo Park, California 94025, United States
5. U.S. Geological Survey, Central Mineral and Environmental
Resources Science Center, Denver Federal Center, Denver, Colorado 80225, United States