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Oligocene-Miocene marine rocks

Massive to thin-bedded, coarse-grained sandstone, conglomerate, conglomeratic sandstone, shale, and sandy shale.
State Washington
Name Oligocene-Miocene marine rocks
Geologic age Oligocene
Primary rock type sandstone
Secondary rock type siltstone
Other rock types shale; olistostrome; tuff; conglomerate
Lithologic constituents
Minor
Sedimentary > Clastic > Sandstone (Tuffaceous)
Sedimentary > Clastic > Sandstone (Bed)Includes arkosic to lithofeldspathic sandstone (Snavely and others, 1993).
Sedimentary > Clastic > Siltstone (Tuffaceous)
Incidental
Sedimentary > Clastic > Siltstone (Bed)
Igneous > Volcanic (Pyroclastic, tuff)
Sedimentary > Clastic > Conglomerate (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)
Sedimentary > Clastic (Olistrostrome)
Map references
Huntting, M. T., Bennett, W. A. G., Livingston, V. E. Jr., Moen, W. S., 1961, Geologic Map of Washington: Washington Division of Mines and Geology, scale 1:500,000.
Unit references
Huntting, M. T., Bennett, W. A. G., Livingston, V. E. Jr., 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.
Rau, W. W., 1967, Geology of the Wynoochee Valley Quadrangle, Grays Harbor County, Washington: Washington Division of Mines and Geology Bulletin no. 56, 51 p.
Babcock, R. S., Suczek, C. A., Engebretson, D. C., 1994, The Cresent "Terrane", Olympic Peninsula and Southern Vancouver Island, in Lasmanis, R. and Cheney, E. S., convenors, Regional Geology of Washington State: Washington Division of Geology and Earth Resources Bulletin 80, p. 141-157.
Snavely, P. D., MacLeod, N. S., Niem, A. R., 1993, Geologic map of the Cape Flattery, Challam Bay, Ozette Lake, and Lake Pleasant Quadrangles, Northwestern Olympic Peninsula, Washington: U. S. Geological Survey Map I-1946, scale 1:48,000.
Wagner, H. C., 1967a, Preliminary geologic map of the South Bend quadrangle, Pacific County, Washington: U. S. Geological Survey Open File Reports 67-266, scale 1:62,500.
Wagner, H. C., 1967b, Preliminary geologic map of the Haymond quadrangle, Pacific County, Washington, U. S. Geological Survey Open File Reports 67-265, scale 1:62,500.
Walsh, T. J., 1987, Geologic Map of the Astoria and Ilwaco Quadrangles, Washington and Oregon: Washington Division of Geology and Earth Resources Open File Report 87-2, scale 1:100,000.
Tabor, R. W. and Cady, W. M., 1978, Geologic Map of the Olympic Peninsula, Washington: U. S. Geological Survey Miscellaneous Investigations Series Map I-994, scale 1:125,000.
Counties Clallam - Grays Harbor - Jefferson - King - Kitsap - Mason - Pacific - Wahkiakum