Miocene-Pliocene volcanic rocks (WAMIPOv;0)

State	Washington
Name	Miocene-Pliocene volcanic rocks
Geologic age	Miocene-Pliocene
Lithologic constituents	Major Igneous > Volcanic > Mafic-volcanic > Basalt (Flow) Incidental Igneous > Volcanic > Felsic-volcanic > Rhyolite (Flow, Pyroclastic-tuff)Includes rhyolitic tuff. Igneous > Volcanic > Mafic-volcanic > Andesite (Flow) Igneous > Volcanic (Pyroclastic-air fall)Pumicite of Ellensburg Formation; may also be described as pumiceous sandstone and siltstone. Sedimentary > Clastic > Conglomerate
Comments	Sedimentary rocks interbedded with Saddle Mountain basalt (which makes up most of this unit) are of Ellensburg Formation, which is mostly conglomerate and pumicite (see unit WAMPLc) (Mackin, 1961, Schuster and others, 1997). The Saddle Mountain Basalt is Miocene-Pliocene in age; the basaltic to rhyolitoc rock, associated with the Teenaway Basalt in the central Cascades, is Eocene in age (Schuster and others, 1997, Tabor and others, 1982).
Stratigraphic units	Columbia lavas; Howson andesite; Post-Roslyn rhyolite; Wenas flow; Saddle Mountain Basalts (in part)
References	Huntting, M.T., Bennett, W.A.G., Livingston, V.E.Jr., and Moen, W.S., 1961, Geologic Map of Washington: Washington Division of Mines and Geology, scale 1:500,000. Schuster, J.E., Gulick, C.W., Reidel, S.P., Fecht, K.R., Zurenko, S., 1997, Geologic Map of Washington--Southeast Quadrant: Washington Division of Geology and Earth Resources Geologic Map GM-45, scale 1:250,000. Stoffel, K.L., Joseph, N.L., Waggoner, S.Z., Gulick, C.W., Korosec, M.A., Bunning, B.B., 1991, Geologic Map of Washington--Northeast Quadrant: Washington Division of Geology and Earth Resources Geologic Map, GM-39, scale 1:250,000. Tabor, R.W., Waitt, R.B.,Jr., Frizzell, V.A.,Jr., Swanson, D.A., Byerly, G.R., Bentley, R.D., 1982, Geologic Map of the Wanatchee 1:100,000 Quadrangle, Central Washington: U. S. Geological Survey Miscellaneous Investigations Series Map I-1311, scale 1:100,000. Grolier, M.J. and Bingham, J.W., 1971, Geologic Map and Sections of Parts of Grant, Adams, and Franklin Counties, Washington: U. S. Geological Survey Miscellaneous Geologic Investigations Map I-589, 6 pls., scale 1:62,500.
NGMDB product	NGMDB product page for 30777
Counties	Benton - Chelan - Grant - Kittitas - Klickitat - Yakima

State

Washington

Name

Miocene-Pliocene volcanic rocks

Geologic age

Miocene-Pliocene

Lithologic constituents

Major

Igneous > Volcanic > Mafic-volcanic > Basalt (Flow)

Incidental

Igneous > Volcanic > Felsic-volcanic > Rhyolite (Flow, Pyroclastic-tuff)Includes rhyolitic tuff.

Igneous > Volcanic > Mafic-volcanic > Andesite (Flow)

Igneous > Volcanic (Pyroclastic-air fall)Pumicite of Ellensburg Formation; may also be described as pumiceous sandstone and siltstone.

Sedimentary > Clastic > Conglomerate

Comments

Sedimentary rocks interbedded with Saddle Mountain basalt (which makes up most of this unit) are of Ellensburg Formation, which is mostly conglomerate and pumicite (see unit WAMPLc) (Mackin, 1961, Schuster and others, 1997). The Saddle Mountain Basalt is Miocene-Pliocene in age; the basaltic to rhyolitoc rock, associated with the Teenaway Basalt in the central Cascades, is Eocene in age (Schuster and others, 1997, Tabor and others, 1982).

Stratigraphic units

Columbia lavas; Howson andesite; Post-Roslyn rhyolite; Wenas flow; Saddle Mountain Basalts (in part)

References

Huntting, M.T., Bennett, W.A.G., Livingston, V.E.Jr., and Moen, W.S., 1961, Geologic Map of Washington: Washington Division of Mines and Geology, scale 1:500,000.

Schuster, J.E., Gulick, C.W., Reidel, S.P., Fecht, K.R., Zurenko, S., 1997, Geologic Map of Washington--Southeast Quadrant: Washington Division of Geology and Earth Resources Geologic Map GM-45, scale 1:250,000.

Stoffel, K.L., Joseph, N.L., Waggoner, S.Z., Gulick, C.W., Korosec, M.A., Bunning, B.B., 1991, Geologic Map of Washington--Northeast Quadrant: Washington Division of Geology and Earth Resources Geologic Map, GM-39, scale 1:250,000.

Tabor, R.W., Waitt, R.B.,Jr., Frizzell, V.A.,Jr., Swanson, D.A., Byerly, G.R., Bentley, R.D., 1982, Geologic Map of the Wanatchee 1:100,000 Quadrangle, Central Washington: U. S. Geological Survey Miscellaneous Investigations Series Map I-1311, scale 1:100,000.

Grolier, M.J. and Bingham, J.W., 1971, Geologic Map and Sections of Parts of Grant, Adams, and Franklin Counties, Washington: U. S. Geological Survey Miscellaneous Geologic Investigations Map I-589, 6 pls., scale 1:62,500.

NGMDB product

NGMDB product page for 30777

Counties

Benton - Chelan - Grant - Kittitas - Klickitat - Yakima