Major Ignimbrites of the Oligocene Parajes Group in the Guazapares Mining District/Cerocahui Basin Region, Northern Sierra Madre Occidental, Western Chihuahua, Mexico

Bryan Patrick Murray, California State Polytechnic University Pomona, Geological Sciences, Pomona, CA, United States and Cathy Busby, University of California Davis, Earth and Planetary Sciences, Davis, CA, United States