Geological Survey investigations in the U12b.01 tunnel, Nevada Test Site - Diment, W.H.; Wilmarth, V.R.; McKeown, F.; Dickey, D.D.; Botinelly, T.; Hinrichs, E. N.; Roach, C.; Byers Jr., F.M.; Izett, G. A.; Johnson, G. R. (Open-File Report, 1959)