1. Department of Geological Sciences, Texas Christian University, Fort Worth, Texas 76129, United States
2. Department of Geosciences, Baylor University, Waco, Texas 76798, United States
3. Department of Physics and Astronomy, Texas Christian University, Fort Worth, Texas 76129, United States
4. Department of Environmental Science, Southern Illinois University−Edwardsville, Edwardsville, Illinois 62026, United States