HACKLEY, Paul C., U.S. Geol Survey, MS 956 National Center, Reston, VA 20192, ALFARO, Guillermo H., Instituto de Geología Económica Aplicada, Universidad de Concepción, Casilla 4107, Concepción, Chile, WARWICK, Peter D., US Geol Survey, 956 National Center, Reston, VA 20192-0001, FINKELMAN, Robert B., U.S.Geol Survey, MS 956 National Center, Reston, VA 20192 and CUEBAS, Rosenelsy M., Department of Earth and Environmental Sciences, California State Univ, Fresno, 2345 East San Ramon Avenue M/S MH24, Fresno, CA 93740, phackley@usgs.gov, phackley@usgs.gov