Robert C Reedy, University of Texas at Austin, Jackson School of Geosciences, Bureau of Economic Geology, Austin, TX, United States, Bridget R Scanlon, University of Texas at Austin, Bureau of Economic Geology, Jackson School of Geosciences, Austin, TX, United States, Mark Engle, University of Texas at El Paso, El Paso, TX, United States and Pei Xu, New Mexico State University Main Campus, Civil Engineering, Las Cruces, NM, United States