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Silicic vent deposits (Pleistocene and Pliocene)

Complex domal masses of rhyolite and dacite that include near-vent flows, breccia, pumicite, perlite, obsidian, and ash-flow tuff
State Oregon
Name Silicic vent deposits (Pleistocene and Pliocene)
Geologic age Pliocene to Pleistocene
Primary rock type rhyolite
Secondary rock type dacite
Other rock types
Lithologic constituents
Major
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Dome)
Igneous > Volcanic > Felsic-volcanic > Dacite (Dome)
Minor
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, ash-flow)
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, ash-flow)
Igneous > Volcanic > Felsic-volcanic > Dacite (Pyroclastic, ash-flow)
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic)
Igneous > Volcanic > Felsic-volcanic > Dacite (Pyroclastic)
Map references
Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.
Unit references
Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.
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.
Counties Deschutes - Klamath - Lake - Wallowa