1. Department of Geology and Geophysics, University of Wyoming, 1000 E. University Ave., Laramie, Wyoming 82071-2000, USA
2. Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Rd. NW, Washington, D.C., 20015, USA
3. Lowell Institute for Mineral Resources, Department of Geosciences, University of Arizona, 1040 East Fourth St., Tucson, Arizona 85721-0077, USA
4. Department of Earth and Atmospheric Science, University of Alberta, Edmonton, Alberta T6G 2E3, Canada