Ross, Clarence S., and Robert L. Smith

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. Near Fine. Item #43965

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, references and index. Bound in original gray stiff paper covers with printing in black. Stamp of Bear Creek Mining Company on the front cover. A near fine copy.

Price: $25.00