Tyee Formation (middle Eocene)

Very thick sequence of rhymically bedded, medium- to fine-grained micaceous, feldspathic, lithic, or arkosic marine sandstone and micaceous carbonaceous siltstone; contains minor interbeds of dacite tuff in upper part. Foraminiferal fauna are referred to the Ulatisian Stage (Snavely and others, 1964). Groove and flute casts indicate deposition by north-flowing turbidity currents (Snavely and others, 1964), but probable provenance of unit is southwest Idaho (Heller and others, 1985)
State Oregon
Name Tyee Formation (middle Eocene)
Geologic age Middle Eocene
Primary rock type sandstone
Secondary rock type siltstone
Other rock types tuff
Lithologic constituents
Major
Sedimentary > Clastic > Sandstone (Bed)
Minor
Sedimentary > Clastic > Siltstone (Bed)
Incidental
Igneous > Volcanic > Felsic-volcanic > Dacite (Pyroclastic, tuff)
Map references
Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.
Unit references
Walker, G.W. and MacLeod, N.S., 1991, Geologic map of Oregon: U.S. Geological Survey, scale 1:500,000.
Snavely, P.D., Jr., Wagner, H.C., and McLeod, N.S., 1964, Rhythmic-bedded eugeosynclinal deposits of the Tyee Formation, Oregon Coast Range: Kansas Geological Survey Bulletin 169, p. 461-480.
Heller, P.L., Peterman, Z.E., O'Neil, J.R., and Shafiqullah, M., 1985, Isotopic provenance of the sandstones of the Eocene Tyee Formation, Oregon Coast Range: Geological Society of America Bulletin, v. 96, p. 770-780.
Counties Benton - Coos - Curry - Douglas - Lane - Lincoln - Polk - Tillamook - Yamhill