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Tertiary dikes, sills, and small intrusive bodies

Dikes are commonly diabase; plugs and sills are generally andesite porphyry and dacite.
State Washington
Name Tertiary dikes, sills, and small intrusive bodies
Geologic age Middle to Late Tertiary
Comments Intrusive bodies in northern Ferry County mostly Scatter Creek quartz monzonite, Scatter Creek Rhyodacite, and minor diorite. Large outcrop in Okanogan County is granitic. Basalt intrusions (sills) in Pacific County, possibly correlative with Columbia River Basalt Group (see WAMv) (Snavely and others, 1973). 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). Also includes andesite porphyry (hypabyssal phase of Fifes Peak andesite--see WAOLMv) of Warren, 1941, as well as hypabyssal volcanic rocks northwest of Mt. Adams (Walsh and others, 1987). Gabbro and diabase dikes and sills on the Olympic Peninsula (Dragovich and others, 2002).
Primary rock type quartz monzonite
Secondary rock type granite
Other rock types basalt; quartz diorite; rhyodacite; tonalite; gabbro; andesite; dacite; rhyolite
Lithologic constituents
Minor
Igneous > Plutonic > Syenitic > Quartz-monzonite (Pluton)
Igneous > Plutonic > Granitic > Granite (Pluton)Also stocks
Igneous > Volcanic > Mafic-volcanic > Basalt (Dike or sill)
Incidental
Igneous > Plutonic > Granitic > Tonalite (Stock or pipe)
Igneous > Hypabyssal > Mafic-hypabyssal > Hypabyssal-andesite (Dike or sill)Andesite porphyries which may represent hypabyssal phase of Fifes Peak volcanism (Warren, 1941). Also domes and stocks.
Igneous > Plutonic > Dioritic > Quartz-diorite (Stock or pipe)Possibly minor in rank.
Igneous > Plutonic > Gabbroic > Gabbro (Dike or sill)Porphyry.
Igneous > Hypabyssal > Felsic-hypabyssal > Hypabyssal-dacite (Dike or sill)Also domes and stocks. May include dacitic vitrophyre and tuffs north of Mt. Rainier.
Igneous > Hypabyssal > Felsic-hypabyssal > Hypabyssal-rhyolite (Dike or sill)Also domes, stocks, and pipes.
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.
Snavely, P. D., Macleod, N. S., Wagner, H. C., 1973, Miocene Tholeiitic Basalts of Coastal Oregon and Washington and Their Relations to Coeval Basalts of the Columbia Plateau: Geological Society of America Bulletin, v. 84, no. 2, p. 387-424.
Weaver, C. E., 1920, The Mineral Resources of Stevens County: Washington Geological Society Bulletin No. 20, 350 p.
Parker, R. L. and Calkins, J. A., 1964, Geology of the Curlew Quadrangle Ferry County Washington, U.S. Geological Survey Bulletin 1169, 95 p.
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.
Rinehart, C. D., and Fox, K. F., Jr., 1972, Geology and Mineral Deposits of the Loomis Quadrangle, Okanogan County, Washington: Washington Division of Mines and Geology Bulletin No. 64, 124 p.
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.
Yates, R. G. and Engels, J. C., 1968, Potassium-Argon Ages of Some Igneous Rocks in Northern Stevens County, Washingon: U. S. Geological Survey Professional Paper 600-D, p. D242-D247.
Snavely, P. D., Jr., Brown, R. D., Roberts, A. E., Rau, W. W., 1958, Geology and Coal Resources of the Centralia-Chelalis District, Washington: U. S. Geological Survey Bulletin 1053, 149 p.
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.
Dragovich, J. D., Logan, R. L., Schasse, H. W., Walsh, T. J., Lingley, W. S., Jr., Norman, D. K., Gerstel, W. J., Lapen, T. J., Schuster, J. E., Meyers, K. D., 2002, Geologic Map of Washington-Northwest Quadrant: Washington Division of Geology and Earth Resources Geologic Map GM-50, scale 1:250,000.
Counties Chelan - Clark - Cowlitz - Ferry - Grays Harbor - King - Kitsap - Kittitas - Lewis - Okanogan - Pacific - Pierce - Skamania - Stevens - Thurston - Whatcom - Yakima