1. Department of Geoscience, University of Nevada–Las Vegas, Las Vegas, Nevada 89154, USA
2. Department of Geosciences, Weber State University, Ogden, Utah 84408, USA
3. Jackson School of Geosciences, University of Texas, Austin, Texas 78712, USA
4. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA