Welded to unwelded, mostly vitric crystal and vitric ash-flow tuff of several ages. Glass in tuff locally altered to clay, zeolites, and secondary silica minerals
State Oregon
Name Tuff
Geologic age Tertiary
Lithologic constituents
Igneous > Volcanic (Pyroclastic-ash flow)various compositions
Comments miscellaneous ash-flow tuffs of various Tertiary ages

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

NGMDB product
Counties Douglas - Jackson - Lane - Linn