State |
Oregon |
Name |
Rhyolitic tuff, tuffaceous sedimentary rocks, and lava flows |
Geologic age |
Late Eocene to Early Miocene |
Lithologic constituents |
Major
Igneous > Volcanic > Felsic-volcanic > Dacite (Flow, Dome, Pyroclastic-air fall, Pyroclastic-ash flow)
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Flow, Dome, Pyroclastic-air fall, Pyroclastic-ash flow)Contains rhyolitic to dacitic pyroclastic rocks, tuffaceous sedimentary rocks, ash-flow tuff, basalt and andesite flows
Minor
Igneous > Volcanic > Mafic-volcanic > Basalt (Flow)
Igneous > Volcanic > Mafic-volcanic > Andesite (Flow)
Sedimentary > Clastic > Mixed-clastic > Sandstone-mudstone (Bed)
|
Comments |
Basalt in the Pike Creek was dated at 21.9 Ma (OR010; recalculated using constants of OR185). |
Stratigraphic units |
Pike Creek Formation (OR005; formerly Pike Creek Volcanic Series; OR062) |
References |
Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.
Walker, G.W. and Repenning, C.A., 1965, Geologic map of Adel quadrangle, Lake, Harney, and Malheur Counties, Oregon: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-446, scale 1:250,000.
https://pubs.er.usgs.gov/publication/i446 Walker, G.W., 1977, Geologic map of Oregon east of the 121st meridian: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-902, scale 1:500,000.
https://pubs.er.usgs.gov/publication/i902 Fuller, R.E., 1931, the geomorphology and volcanic sequence of Steens Mountain in southeastern Oregon: University of Washington Publication in Geology, v. 3, no. 1, 130 p.
Swanson, D.A. and Robinson, P.T., 1968, Base of the John Day Formation in and near Horse Heaven Mining District, north-central Oregon: U.S. Geological Survey Professional Paper 600-D, p. D154-D161
https://pubs.er.usgs.gov/publication/pp600D Minor, S.A., Rytuba, J.J., Grubensky, M.J., Vander Meulen, D.B., Goeldner, C.A., and Tegtmeyer, K.J., 1987, Geologic map of the High Steens and Little Blitzen Gorge Wilderness Study Areas, Harney County, Oregon: U.S. Geological Surevy Miscellaneous Field Studies Map MF-1876, scale 1:24,000.
Evans, J.G., 1993, Geologic map of the Brannan Gulch quadrangle, Baker County, Oregon: U.S. Geological Survey Geological Quadrangle GQ-1744, scale 1:24,000.
https://pubs.er.usgs.gov/publication/gq1744 Minor, S.A., Rytuba, J.J., Goeldner, C.A., and Tegtmeyer, K.J., 1987, Geologic map of the Alvord Hot Spring quadrangle, Harney County, Oregon: U.S. Geological Survey Miscellaneous Field Studies Map MF-1916, scale 1:24,000.
https://pubs.er.usgs.gov/publication/mf1916 Minor, S.A., Rytuba, J.J., Vander Meulen, D.B., Grubensky, M.J., and Tegtmeyer, K.J., 1987e, Geologic map of the Wildhorse Lake quadrangle, Harney County, Oregon: U.S. Geological Survey Miscellaneous Field Studies Map MF-1915, scale 1:24,000.
https://pubs.er.usgs.gov/publication/mf1915
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NGMDB product |
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Counties |
Baker - Crook - Deschutes - Harney - Klamath - Lake - Union - Wheeler
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