Sedimentary and volcaniclastic rocks

Lapilli tuff, mudflow deposits (lahars), flow breccia, and volcanic conglomerate, mostly of basaltic to dacitic composition; rare iron-stained palagonitic tuff and breccia of basaltic and andesitic composition; and ash-flow, air-fall, and water-laid tuff of dacitic to rhyolitic composition. The palagonite tuff and breccia grade laterally into peperite and into lava flows of basalt and basaltic andesite
State Oregon
Name Sedimentary and volcaniclastic rocks
Geologic age Tertiary
Lithologic constituents
Igneous > Volcanic > Mafic-volcanic (Pyroclastic-tuff, Volcaniclastic-lahar)
Igneous > Volcanic > Felsic-volcanic (Pyroclastic-tuff, Volcaniclastic-lahar)
Sedimentary > Clastic (Bed)
Comments assorted rocks

Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.

NGMDB product
Counties Clackamas - Douglas - Jackson - Lane - Linn