Basaltic lava flows

Basaltic and basaltic andesite lava flows and breccia; grades laterally into rare bedded palagonitic tuff and breccia
State Oregon
Name Basaltic lava flows
Geologic age Oligocene to Miocene
Primary rock type basalt
Secondary rock type volcanic breccia (agglomerate)
Other rock types
Lithologic constituents
Major
Igneous > Volcanic > Mafic-volcanic > Basalt (Flow)
Igneous > Volcanic > Mafic-volcanic > Basaltic-andesite (Flow)
Minor
Igneous > Volcanic > Mafic-volcanic > Basalt (Volcaniclastic, volcanic breccia)
Igneous > Volcanic > Mafic-volcanic > Basaltic-andesite (Volcaniclastic, volcanic breccia)
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.
Counties Clackamas