Phreatic Eruptions of the Eastern Snake River Plain of Idaho
Womer MB, Greeley R, King JS. 1982. Phreatic Eruptions of the Eastern Snake River Plain of Idaho. Pages 453-464. In Bonnichsen B and Breckenridge RM (ed). Cenozoic Geology of Idaho. Idaho Bureau of Mines. Moscow, ID
Split Butte and Sand Butte are tuff cones representing phreatomagmatic eruptions. Both buttes are nested, subcircular structures consisting of a tephra ring and an inner lava lake modified by a pit crater. Split Butte lies west of the Wapi lava flow, about 40 kilometers west-northwest of American Falls, and consists of vitric ash that forms a ring 600 meters across. Sand Butte is 30 kilometers southwest of Carters of the Moon National Monument and consists of palagonitized vitric ash and abundant lithic fragments which form a cone 1.2 kilometers across; a deeper level of magma-water interaction at Sand Butte is suggested by a greater fraction of lithic ejecta and less vesiculation of the juvenile fraction.
- Type
- Book Chapter
- Authors
- Womer, M; Greeley, R; King, J
- Units
- CRMO
- Keywords
- phreatic eruptions, Physical Sciences, Sand Butte, Split Butte