Upper Eocene volcanic rocks (WAEOv1r;0)

State	Washington
Name	Upper Eocene volcanic rocks
Geologic age	Late-Middle Eocene
Lithologic constituents	Major Igneous > Volcanic > Felsic-volcanic > Rhyolite (Flow, Dome, Pyroclastic-tuff) Minor Igneous > Volcanic > Mafic-volcanic > Basalt (Flow, Volcaniclastic-volcanic breccia) Incidental Metamorphic > Metasedimentary > Metaclastic > Argillite Sedimentary > Clastic > Siltstone (Bed) Sedimentary > Clastic > Mudstone > Shale (Bed) Igneous > Volcanic > Mafic-volcanic > Andesite (Flow, Volcaniclastic-volcanic breccia)Possibly minor in rank but subordinate to rhyolite and basalt. Sedimentary > Clastic > Sandstone (Bed) Sedimentary > Coal (Bed)Rare occurrence in Naches Formation; may or may not occur in this unit.
Comments	Two stratigraphic units in WAEv1r, "Kachess rhyolite" and "Rhyolite in the Guye", were listed in Huntting and others, 1961, with a footnote referencing a 1906 USGS geologic atlas folio by G. O. Smith and F. C. Calkins; none of the referenced literature in this database names any outcrops similarly. Furthermore, any rhyolite within the Guye Formation is geographically more likely to occur in either WAEPKc (which includes the Guye Formation) or WAlTv (which includes the Mt. Catherine rhyolite adjacent to the Guye Formation). The Kachess rhyolite must be associated with Kachess Lake just north of the unit.
Stratigraphic units	Naches Formation (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. Walsh, T.J., Korosec, M.A., Phillips, W.M., Logan, R.T., Schasse, H.W., 1987, Geologic Map of Washington-Southwest Quadrant: Washington Division of Geology and Earth Resources, Geologic Map GM-34, scale 1:250,000. Dragovich, J.D., Logan, R.L., Schasse, H.W., Walsh, T.J., Lingley, W.S., Jr., Norman, D.K., Gerstel, W.J., Lapen, T.J., Schuster, J.E., Meyers, K.D., 2002, Geologic Map of Washington-Northwest Quadrant: Washington Division of Geology and Earth Resources Geologic Map GM-50, scale 1:250,000. Tabor, R.W., Frizzell, V.A., Jr., Booth, D.B.., Waitt, R.B., 2000, Geologic Map of the Snoqualmie Pass 30 x 60 Minute Quadrangle, Washington: U. S. Geological Survey Geologic Investigations Series I-2538, 57 p., 1 pl.
NGMDB product	NGMDB product page for 30777
Counties	Kittitas

State

Washington

Name

Upper Eocene volcanic rocks

Geologic age

Late-Middle Eocene

Lithologic constituents

Major

Igneous > Volcanic > Felsic-volcanic > Rhyolite (Flow, Dome, Pyroclastic-tuff)

Minor

Igneous > Volcanic > Mafic-volcanic > Basalt (Flow, Volcaniclastic-volcanic breccia)

Incidental

Metamorphic > Metasedimentary > Metaclastic > Argillite

Sedimentary > Clastic > Siltstone (Bed)

Sedimentary > Clastic > Mudstone > Shale (Bed)

Igneous > Volcanic > Mafic-volcanic > Andesite (Flow, Volcaniclastic-volcanic breccia)Possibly minor in rank but subordinate to rhyolite and basalt.

Sedimentary > Clastic > Sandstone (Bed)

Sedimentary > Coal (Bed)Rare occurrence in Naches Formation; may or may not occur in this unit.

Comments

Two stratigraphic units in WAEv1r, "Kachess rhyolite" and "Rhyolite in the Guye", were listed in Huntting and others, 1961, with a footnote referencing a 1906 USGS geologic atlas folio by G. O. Smith and F. C. Calkins; none of the referenced literature in this database names any outcrops similarly. Furthermore, any rhyolite within the Guye Formation is geographically more likely to occur in either WAEPKc (which includes the Guye Formation) or WAlTv (which includes the Mt. Catherine rhyolite adjacent to the Guye Formation). The Kachess rhyolite must be associated with Kachess Lake just north of the unit.

Stratigraphic units

Naches Formation (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.

Walsh, T.J., Korosec, M.A., Phillips, W.M., Logan, R.T., Schasse, H.W., 1987, Geologic Map of Washington-Southwest Quadrant: Washington Division of Geology and Earth Resources, Geologic Map GM-34, scale 1:250,000.

Dragovich, J.D., Logan, R.L., Schasse, H.W., Walsh, T.J., Lingley, W.S., Jr., Norman, D.K., Gerstel, W.J., Lapen, T.J., Schuster, J.E., Meyers, K.D., 2002, Geologic Map of Washington-Northwest Quadrant: Washington Division of Geology and Earth Resources Geologic Map GM-50, scale 1:250,000.

Tabor, R.W., Frizzell, V.A., Jr., Booth, D.B.., Waitt, R.B., 2000, Geologic Map of the Snoqualmie Pass 30 x 60 Minute Quadrangle, Washington: U. S. Geological Survey Geologic Investigations Series I-2538, 57 p., 1 pl.

NGMDB product

NGMDB product page for 30777

Counties

Kittitas