Yaquina Formation (lower Miocene and upper Oligocene) (ORTyq;0)

Thick- to thin-bedded sandstone, conglomerate, and tuffaceous siltstone of deltaic origin; locally contains thin coal and ash beds. Conglomerate contains abundant clasts of pumice and dacitic volcanic rocks. In places includes thick lenses of marine tuffaceous siltstone and fine-grained sandstone. Foraminifers in formation assigned to the Zemorrian and lower part of the Saucesian Stages of Kleinpell (1938) and molluscan fauna to the lower Blakeley Stage of Weaver and others (1944)

State	Oregon
Name	Yaquina Formation (lower Miocene and upper Oligocene)
Geologic age	Late Oligocene to Early Miocene
Original map label	Tyq
Primary rock type	sandstone
Secondary rock type	conglomerate
Other rock types	siltstone; coal; tuff
Lithologic constituents	Major Sedimentary > Clastic > Sandstone (Bed) Minor Sedimentary > Clastic > Siltstone (Bed) Sedimentary > Clastic > Conglomerate (Bed) Incidental Igneous > Volcanic (Pyroclastic, tuff) Sedimentary > Coal (Bed)
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. Kleinpell, R.M., 1938, Miocene stratigraphy of California: Tulsa, Oklahoma, American Association of Petroleum Geologists, 450 p. Weaver, C.E., Beck S., bramlette, M.N., Carlson, s., and others, 1944, Correlation of the marine Cenozoic formations of western North America [Chart 11]: Geological Society of America Bulletin, v. 55, p. 569-598.
Geographic coverage	Lincoln