Pre-Carboniferous intrusive rocks

Meta-quartz diorite, hypersthene diorite, and gneissose and directionless quartz diorite of eastern Skagit County. Quartz diorite and diorite in the San Juan Islands. Includes amphibolite and gneiss locally.
State Washington
Name Pre-Carboniferous intrusive rocks
Geologic age Paleozoic
Lithologic constituents
Igneous > Plutonic > Dioritic > Quartz-diorite (Pluton)Includes meta-quartz diorite.
Igneous > Plutonic > Granitic > Tonalite (Pluton)Includes trondhjemite and meta-tonalite. Possibly major in rank.
Igneous > Plutonic > Gabbroic > Gabbro (Pluton)
Sedimentary > Clastic (Bed)May include sandstone, siltstone, conglomerate, breccia, and tuff of Fidalgo Complex.
Metamorphic > Metasedimentary > Metaclastic > ArgilliteAssociated with Fidalgo Complex.
Igneous > Volcanic > Mafic-volcanic > Basalt (Flow)
Igneous > Plutonic > Dioritic > Diorite
Sedimentary > Chemical > ChertAssociated with Fidalgo Complex.
Igneous > Plutonic > Ultramafic > Pyroxenite
Metamorphic > Amphibolite
Igneous > Volcanic > Mafic-volcanic > Andesite (Flow)
Igneous > Volcanic > Felsic-volcanic > Dacite (Flow)
Metamorphic > Gneiss (Greenschist)Includes tonalite gneiss and flaser gneiss associated with the Marblemount quartz diorite and orthogneiss of Turtleback and Yellow Aster Complexes. Possibly minor in rank.
Comments Meta-quartz diorite of Marblemount is greenschist facies (Misch, 1977). Turtleback and Yellow Aster Complexes are metamorphosed to greenschist and amphibolite facies (Dragovich and others, 2002).
Stratigraphic units Marblemount quartz diorite; Turtleback Complex (in part); Fidalgo Complex (in part); Yellow Aster Complex (in part)

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.

Brandon, M.T., 1989, Geology of the San Juan-Cascade Nappes, northwestern Cascade Range and San Juan Islands, in Joseph, N. L. (Ed.), Geologic Guidebook for Washington and Adjacent Areas: prepared for the 85th Annual Meeting of the Cordilleran Section, Geological Society of America, May 8-11, 1989, Spokane, Washington: Washington Division of Geology and Earth Resource Infomation Circular 86, p. 137-162.

Misch, P., 1979, Geologic Map of the Marblemount Quadrangle, Washington: Washington Division of Geology and Earth Resources Geologic Map GM-23, scale 1:48,000.

Misch, P., 1977, Bedrock Geology of the North Cascades, in Brown, E. H. and Ellis, R. C. (eds.), Geological Excursions in the Pacific Northwest, Geological Society of America 1977 Annual Meeting, Seattle: Western Washington University, p. 1-62.

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.

NGMDB product
Counties Chelan - San Juan - Skagit