|Name||Undifferentiated tuffaceous sedimentary rocks, tuffs, and basalt|
|Geologic age||Oligocene to Miocene|
Igneous > Volcanic > Mafic-volcanic > Basaltic-andesite (Flow, Volcaniclastic-volcanic breccia)
Igneous > Volcanic > Mafic-volcanic > Basalt (Flow, Volcaniclastic-volcanic breccia)
Igneous > Volcanic > Felsic-volcanic > Dacite (Pyroclastic-air fall, Pyroclastic-ash flow, Volcaniclastic-lahar)
Sedimentary > Clastic > Mixed-clastic (Bed)
Igneous > Volcanic > Mafic-volcanic > Andesite (Pyroclastic-air fall, Pyroclastic-ash flow, Volcaniclastic-lahar)
Sedimentary > Clastic > Conglomerate (Bed)
Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.
Peck, D.L., Griggs, A.B., Schlicker, H.G., Well, F.G., and Dole, H.M., 1964, Geology of the central and northern parts of the Western Cascade Range in Oregon: U.S. Geolotgical Survey Professional Paper 449, 56 p.
Thayer, T.P., 1933, Structural relations of central Willamette Valley to Cascade Mountains: Pan American Geologist, v. 59, p. 317.
Thayer, T.P., 1936, Structure of the North Santiam River section of the cascade Mountains in Oregon: Journal of Geology, v. 44, p. 701-716.
Thayer, T.P., 1939, Geology of the Salem Hills and the North Santiam River basin, Oregon: Oregon Department of Geology and Mineral Industries Bulletin 15, 40 p.
Hammond, P.E., Geyer, K.M., and Anderson, J.L., 1982, Preliminary geologic map and cross sections of the upper Clackamas and North Santiam Rivers area, northern Oregon Cascade Range: Portland State University Department of Earth Sciences, Portland, Oregon, scale 1:62,500.
Eubanks, W., 1960, Fossil woods of the Thomas Creek area, Linn County, Oregon: The Ore Bin, v. 22, p. 65-69.
Miller, P.R., and Orr, W.N., 1984a, Geologic map of the Wilhoit quadrangle, Oregon: Oregon Department of Geologyand Mineral Industries Geologic Map Series GMS032, scale 1:24,000.
Trimble, D.E., 1963, geology of Portland, Oregon, and adjacent areas: U.S. Geological Survey Bulletin 1119, 110 p.
Waters, A.C., 1973, The Columbia River Gorge-basalt stratigraphy, ancient lava dams, and landslide dams, in Geologic field trips in northern Oregon and southern Washington: Oregon Department of Geology and Mineral Industries Bulletin 77, p. 135-154.
Wolfe, J.A., 1981, A chronologic framework for Cenozoic megafossil floras of northwestern North America and its relation to marine geochronology, in Armentrout, J.M., ed., Pacific Northwest Cenozoic Biostratigraphy: Geological Society of America Special Paper 184, p. 39-47.
Smith, J.G., Page, N.J, Johnson, M.G., Moring, B.C., and Gray, F., 1982, Preliminary geologic map of the Medford 1ø by 2ø quadrangle, Oregon and California: U.S. Geological Survey Open-File Report 82-955, scale 1:250,000.
Smith, J.G., 1980, An important lower Oligocene welded-tuff marker bed in the western Cascade Range of southern Oregon: Geological Society of America Abstracts with Programs, v. 12, p. 153.
Evernden, J. F., and James, G.T., 1964, Potassium-argon dates and the Tertiary floras of North America: American Journal of Science, v. 262, p. 945-974.
Fiebelkorn, R.B., Walker, G.W., Macleod, N.S., McKee, E.H., and Smith, J.G., 1983, Index to K-Ar determinations for the State of Oregon: Isochron/West, no. 37, p. 3-60.
Verplanck, E.P., 1985, Temporal variations in volume and geochemistry of volcanism in the Western Cascades, Oregon: Corvallis, Oregon, Oregon State University, M.S. Thesis, 115 p.
|Counties||Clackamas - Douglas - Jackson - Lane - Linn - Marion|