Pyroclastic ejecta of basaltic cinder cones

Mostly unconsolidated, oxidized, fine to course, scoriaceous cinders, bombs, and agglutinate deposited in subaerial environment
State Oregon
Name Pyroclastic ejecta of basaltic cinder cones
Geologic age Miocene to Early Pliocene
Lithologic constituents
Igneous > Volcanic > Mafic-volcanic > Basalt (Pyroclastic-air fall)Also contains andesite
Igneous > Volcanic > Mafic-volcanic > Andesite (Pyroclastic-air fall)

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.

Swisher, C.C., Ach, J.A., and Hart, W.K., 1990, Laser fusion 40Ar/39Ar dating of the type Steens Mountain Basalt, southeastern Oregon, and the age of the Steens aeromagnetic polarity transition [abs.]: EOS, Transactions of American Geophysical Union, v. 17, no. 43, p. 1,296.

Beeson, J.H., Geology of the southern half of the Huntington quadrangle, Oregon: Eugene, University of Oregon, master's thesis, 77 p.

NGMDB product
Counties Baker - Crook - Harney - Klamath - Lake - Linn - Malheur - Wasco