| State | Oregon |
|---|---|
| Name | Pyroclastic ejecta of basaltic cinder cones |
| Geologic age | Miocene to Early Pliocene |
| Lithologic constituents |
Major
Igneous > Volcanic > Mafic-volcanic > Basalt (Pyroclastic-air fall)Also contains andesite
Minor
Igneous > Volcanic > Mafic-volcanic > Andesite (Pyroclastic-air fall)
|
| 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.https://pubs.er.usgs.gov/publication/i902 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 |