ASH-FLOW TUFFS: THEIR ORIGIN, GEOLOGIC RELATIONS, AND IDENTIFICATION: PROFESSIONAL PAPER 366
Washington, DC: United States Geological Survey/USGS/Government Printing Office/GPO, 1961. Soft cover. A study of the emplacement, by flowage, of hot gas-emitting volcanic ash; its induration by welding and crystallization, and criteria for recognizing the resulting rock. 81 pages with map, photographic examples of welded tuffs, other photographs, two color photographs..... More



