Pre-Upper Jurassic metamorphic rocks of the medium and high-grade zone

Schist, amphibolite, and minor lime-silicate rocks, marble, quartzite, and metaconglomerate.
State Washington
Name Pre-Upper Jurassic metamorphic rocks of the medium and high-grade zone
Geologic age Early Jurassic-Triassic
Lithologic constituents
Major
Metamorphic > SchistIncludes biotite schist, hornblende-mica schist, calc-silicate schist, greenschist, and mica-quartz schist.
Minor
Metamorphic > Amphibolite
Metamorphic > GneissIncludes biotite and hornblende orthogneiss, and possibly augen gneiss or paragneiss.
Incidental
Metamorphic > Migmatite
Metamorphic > MetasedimentaryIncludes metaconglomerate and meta-greywacke.
Igneous > Plutonic > Granitic > Tonalite
Metamorphic > Metasedimentary > Metacarbonate > MarblePossibly minor in rank, though unlikely.
Metamorphic > Metasedimentary > Metaclastic > Quartzite
Metamorphic > Metasedimentary > Metaclastic > Phyllite
Igneous > Plutonic > Dioritic > Quartz-diorite
Igneous > Plutonic > Gabbroic > Gabbro
Comments Cascade River schist grades from the chlorite zone to the staurolite-kyanite zone (Misch, 1977). The Lookout Mountain formation is intruded by 157 Ma quartz diorite (Walsh and others, 1987). The Chiwaukum Schist is a Barrovian sequence of metasedimentary rocks and some metavolcanic rocks (Duggan and Brown, 1994).
Stratigraphic units Contact schist; Ruby Creek migmatites; Leecher metamorphics; Elijah Ridge Schist; Cascade River Schist; Lookout Mountain Formation; Chiwaukum Schist (in part)
References

Huntting, M.T., Bennett, W.A.G., Livingston, V.E.Jr., and 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.

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.

Cater, F.W. and Wright, T.L., 1967, Geologic Map of the Lucerne Quadrangle, Chelan County, Washington: U. S. Geological Survey Geologic Quadrangle Map GQ-647, scale 1:62,500.

Cater, F.W. and Crowder, D.F., 1967, Geologic Map of the Holden Quadrangle, Snohomish and Chelan Counties, Washington: U. S. Geological Survey Geologic Quadrangle Map GQ-646, scale 1:62,500.

Crowder, D.F., Tabor, R.W., Ford, A.B., 1966, Geologic Map of the Glacier Peak Quadrangle, Snohomish and Chelan Counties, Washington: U. S. Geological Survey Geologic Quadragle Maps GQ-473, scale 1:62,500.

Barksdale, J.D., 1975, Geology of the Methow Valley, Okanogan County, Washington: Washington Division of Geology and Earth Resources Bulletin no. 48, 72 p.

Tabor, R.W., Frizzell, V.A.,Jr., Booth, D.B., Waitt, R.B., Whetten, J.T., Zartman, R.E., 1993, Geologic Map of the Skykomish River 30- by 60-Minute Quadrangle, Washington: U. S. Geological Survey Miscellaneous Investigations Series Map I-1963, scale 1:100,000.

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.

Duggan, K.M. and Brown, E.H., 1994, Correlation of the Tonga Formation and Chiwaukum Schist, North Cascades, Washington: Implications for Late Cretaceous orogenic mechanisms: Tectonics, v. 13, no. 6, p. 1411-1424.

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Counties Chelan - Douglas - King - Kittitas - Okanogan - Skagit - Snohomish - Whatcom