Oligocene nonmarine rocks (WAOGc;0)

State	Washington
Name	Oligocene nonmarine rocks
Geologic age	Oligocene
Lithologic constituents	Major Sedimentary > Clastic > Conglomerate (Tuffaceous) Minor Igneous > Volcanic > Mafic-volcanic (Pyroclastic-tuff, Volcaniclastic-volcanic breccia)Includes "lake beds" of Ferry County (Muessig, 1967). Referred to as "volcanic tuff" in literature; assumed to be mafic because of local andesite and basalt flows in both this unit and adjacent units. Sedimentary > Clastic > Sandstone (Tuffaceous) Incidental Igneous > Volcanic > Mafic-volcanic > Basalt Igneous > Volcanic > Mafic-volcanic > Andesite (Flow) Sedimentary > Clastic > Siltstone (Tuffaceous)Possibly of minor rank, but in less abundance than sandstone. Unconsolidated > Fine-detrital > Clay Sedimentary > Coal > Lignite
Comments	Includes very small outcrop in southern Stevens County which has been mapped as Gerome Andesite (note, however, that Stoffel and others, 1991, report that while the term "Gerome Andesite" was once widely used, it has since been abandoned). Some discrepancy over the lithology near Republic: Muessig, 1967, identifies the Tom Thumb Tuff Member as thin-bedded fine tuff while Stoffel, 1990, identifies it as primarily fossiliferous shale beds. The Eagle Creek Formation is almost entirely volcanic material: mostly andesite flows, tuff, and breccia, with some trachyte, trachyandesite, and basalt; lithology and stratigraphy suggests contemporaneity with Fifes Peak andestite (see WAOLMv) (Warren, 1941).
Stratigraphic units	Klondike Mtn Formation (in part: Tom Thumb Tuff Member); Toutle formation; Eagle Creek Formation; Ellensburg Formation (in small 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. Warren, W.C., 1941, Relation of the Yakima Basalt to the Keechelus Andesite Series: The Journal of Geology, v. 49, p. 795-814. Muessig, S., 1967, Geology of the Republic Quadrangle and a Part of the Aeneas Quadrangle, Ferry County, Washington: U. S. Geological Survey Bulletin 1216, 135 p. 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. Roberts, A.E., 1958, Geology and Coal Resources of the Toledo-Castle Rock District, Cowlitz and Lewis Counties, Washington: U. S. Geological Survey Bulletin 1062, 71 p, 6 pls. Phillips, W.M., 1987, Geologic Map of the Vancouver Quadrangle, Washington and Oregon: Washington Division of Geology and Earth Resources Open File Report 87-10, scale 1:100,000. Korosec, M.A., 1987, Geologic Map of the Hood River Quadrangle, Washington and Oregon: Washington Division of Geology and Earth Resources Open File Report 87-6, scale 1:100,000. Becraft, G.E. and Weis, P.L., 1963, Geology and Mineral Deposits of the Turtle Lake Quadrangle, Washington: U. S. Geological Survey Bulletin 1131, 73 p., 2 pls. Stoffel, K.L., 1990, Geologic Map of the Republic 1:100,000 Quadrangle, Washington: Washington Division of Geology and Earth Resources Open File Report 90-10, 62 p, 1 pl.
NGMDB product	NGMDB product page for 30777
Counties	Cowlitz - Ferry - Klickitat - Skagit - Skamania - Snohomish - Stevens

State

Washington

Name

Oligocene nonmarine rocks

Geologic age

Oligocene

Lithologic constituents

Major

Sedimentary > Clastic > Conglomerate (Tuffaceous)

Minor

Igneous > Volcanic > Mafic-volcanic (Pyroclastic-tuff, Volcaniclastic-volcanic breccia)Includes "lake beds" of Ferry County (Muessig, 1967). Referred to as "volcanic tuff" in literature; assumed to be mafic because of local andesite and basalt flows in both this unit and adjacent units.

Sedimentary > Clastic > Sandstone (Tuffaceous)

Incidental

Igneous > Volcanic > Mafic-volcanic > Basalt

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

Sedimentary > Clastic > Siltstone (Tuffaceous)Possibly of minor rank, but in less abundance than sandstone.

Unconsolidated > Fine-detrital > Clay

Sedimentary > Coal > Lignite

Comments

Includes very small outcrop in southern Stevens County which has been mapped as Gerome Andesite (note, however, that Stoffel and others, 1991, report that while the term "Gerome Andesite" was once widely used, it has since been abandoned). Some discrepancy over the lithology near Republic: Muessig, 1967, identifies the Tom Thumb Tuff Member as thin-bedded fine tuff while Stoffel, 1990, identifies it as primarily fossiliferous shale beds. The Eagle Creek Formation is almost entirely volcanic material: mostly andesite flows, tuff, and breccia, with some trachyte, trachyandesite, and basalt; lithology and stratigraphy suggests contemporaneity with Fifes Peak andestite (see WAOLMv) (Warren, 1941).

Stratigraphic units

Klondike Mtn Formation (in part: Tom Thumb Tuff Member); Toutle formation; Eagle Creek Formation; Ellensburg Formation (in small 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.

Warren, W.C., 1941, Relation of the Yakima Basalt to the Keechelus Andesite Series: The Journal of Geology, v. 49, p. 795-814.

Muessig, S., 1967, Geology of the Republic Quadrangle and a Part of the Aeneas Quadrangle, Ferry County, Washington: U. S. Geological Survey Bulletin 1216, 135 p.

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.

Roberts, A.E., 1958, Geology and Coal Resources of the Toledo-Castle Rock District, Cowlitz and Lewis Counties, Washington: U. S. Geological Survey Bulletin 1062, 71 p, 6 pls.

Phillips, W.M., 1987, Geologic Map of the Vancouver Quadrangle, Washington and Oregon: Washington Division of Geology and Earth Resources Open File Report 87-10, scale 1:100,000.

Korosec, M.A., 1987, Geologic Map of the Hood River Quadrangle, Washington and Oregon: Washington Division of Geology and Earth Resources Open File Report 87-6, scale 1:100,000.

Becraft, G.E. and Weis, P.L., 1963, Geology and Mineral Deposits of the Turtle Lake Quadrangle, Washington: U. S. Geological Survey Bulletin 1131, 73 p., 2 pls.

Stoffel, K.L., 1990, Geologic Map of the Republic 1:100,000 Quadrangle, Washington: Washington Division of Geology and Earth Resources Open File Report 90-10, 62 p, 1 pl.

NGMDB product

NGMDB product page for 30777

Counties

Cowlitz - Ferry - Klickitat - Skagit - Skamania - Snohomish - Stevens