F. G. Poole Harley Barnes P. P. Orkild F.M. Byers Jr. W. J. Carr F. A. McKeown F. N. Houser E.M. Shoemaker W.L. Emerick Robert Lorenz Christiansen 1969 application/pdf 10.3133/ofr6938 en U.S. Geological Survey Guidebook for past field trips to the Nevada Test Site reports