Basalt and andesite intrusions (Pliocene, Miocene, and Oligocene?) (ORTib;0)

Sills, plugs and dikes of basaltic andesite, basalt, and andesite. Mostly represents feeders, exposed by erosion, for flows and flow breccias of units Tba and Trb. Includes a few dikes of hornblende and plagioclase porphyritic andesite, commonly altered, and aphyric basaltic andesite that probably were feeders for parts of unit Tub

State	Oregon
Name	Basalt and andesite intrusions (Pliocene, Miocene, and Oligocene?)
Geologic age	Oligocene(?) to Pliocene
Original map label	Tib
Primary rock type	basalt
Secondary rock type	andesite
Other rock types
Lithologic constituents	Minor Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-andesite (Stock or pipe) Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-basaltic-andesite (Stock or pipe) Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-basalt (Pyroclastic, tuff) Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-basaltic-andesite (Dike or sill) Incidental Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-andesite (Dike or sill) Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-basalt (Dike or sill)
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.
Geographic coverage	Clackamas - Douglas - Hood River - Jackson - Jefferson - Klamath - Lane - Linn - Malheur - Marion - Multnomah