Nopal No. 1 Mine, Sierra Peña Blanca, Peña Blanca District, Mun. de Aldama, Chihuahua, Mexico

333 metric tons of U3O8 "breccia pipe"

References:
- Econ Geol (1991) 86:233-248
- Panczner (1987): 136, 392.
- Pearcy, E.C., Prikryl, J.D., Murphy, W.M., and Leslie, B.W. (1994): Alteration of uraninite from the Nopal I deposit, Peña Blanca District, Chihuahua, Mexico, compared to degradation of spent nuclear fuel in the proposed U.S. high-level nuclear waste repository at Yucca Mountain, Nevada. Appl. Geochem.: : 713-732.
- Prikryl, J.D., D.A. Pickett, W.M. Murphy, and E.C. Pearcy (1997): Migration behavior of naturally-occurring radionuclides at the Nopal I uranium deposit, Chihuahua, Mexico. Journal of Contaminant Hydrology, 26, 61-69.
- http://www.swri.org/4org/d20/ghs/PBlanca/mineral.html