Tuffaceous sedimentary rocks and tuffs (lower? Pleistocene or Pliocene) (ORQTst;0)

State	Oregon
Name	Tuffaceous sedimentary rocks and tuffs (lower? Pleistocene or Pliocene)
Geologic age	Pliocene to Early Pleistocene
Original map label	QTst
Comments	Unit also occurs in eastern Oregon
Primary rock type	rhyolite
Secondary rock type	andesite
Other rock types	pumice
Lithologic constituents	Major Igneous > Volcanic > Mafic-volcanic > Andesite (Pyroclastic, ash-flow) Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, ash-flow)Containsrhyolitic to andesitic ash-flow tuff, pumice fall deposits, minor mudflows,and alluvium on flanks of newberry Volcano Minor Sedimentary > Clastic > Conglomerate (Bed) Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, air fall)
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. [http://pubs.er.usgs.gov/publication/i902] Macleod, N.S., Sherrod, D.R., Chitwood, L.A., and McKee, E.H., 1981, Newberry volcano, Oregon, in Johnston, D. A. and Donnelly-Nolan, Julie, eds., Guides to some volcanic terranes in Washington, Idaho, Oregon, and northern California: U.S. Geological Survey Circular 838, 189 p. [http://pubs.er.usgs.gov/publication/cir838]
Geographic coverage	Deschutes - Lake