ISSN 1941-8264 George E. Gehrels, Ron Blakey, Karl E. Karlstrom, J. Michael Timmons, Bill Dickinson, and Mark Pecha Detrital zircon U-Pb geochronology of Paleozoic strata in the Grand Canyon, ArizonaLithosphere, June 2011, v. 3, p. 183-200 Ryan Porter, George Zandt, and Nadine McQuarrie Pervasive lower-crustal seismic anisotropy in Southern California: Evidence for underplated schists and active..