Pre-Tertiary ultrabasic intrusive rocks (WApTb;0)

State	Washington
Name	Pre-Tertiary ultrabasic intrusive rocks
Geologic age	Late-Jurassic
Original map label	pTb
Comments	The Fidalgo group is located on the San Juan Islands; the Ingalls Tectonic Complex is located in central Washington and makes up the bulk of this unit. The Ingalls Tectonic Complex represents an ophiolite with facies grading from greenschist and zeolitic (prehnite-pumpellyite) to hornfels at its contact with the Mt. Stuart batholith (Tabor and others, 1982, 1987). Dragovich and others, 2002, reports that most of this unit is metamorphosed to talc-, tremolite-, or anthophyllite-bearing rock near plutons to silica-carbonate rock near faults. The referenced literature does not specify facies for each lithology, but I would assume that all of the above grades can be applied to almost all the lithologies though relative quantities of each lithology and facies combination are unknown; hence I do not specify facies in the lithology coding.
Primary rock type	serpentinite
Secondary rock type	peridotite
Other rock types	pyroxenite; hornfels; schist; amphibolite; granofels; greenstone; phyllite; diorite; gabbro
Lithologic constituents	Major Metamorphic > SerpentiniteIncludes serpentinized peridotite and serpentinized pyroxinite. Minor Igneous > Plutonic > Ultramafic > PeridotiteMay include dunite (see WApTd for dunite of Fidalgo complex). Incidental Igneous > Plutonic > Gabbroic > Gabbro Igneous > Plutonic > Dioritic > Diorite Metamorphic > Phyllite Metamorphic > Greenstone Metamorphic > Granofels Metamorphic > Amphibolite Metamorphic > Schist Metamorphic > Hornfels Igneous > Plutonic > Ultramafic > Pyroxenite
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. 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. Foster, R. J., 1960, Tertiary Geology of a Portion of the Central Cascade Mountains, Washington: Geological Society of America Bulletin v. 71, no. 2, p. 99-126. 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. [http://pubs.er.usgs.gov/publication/i1963] Tabor, R. W., Frizzell, V. A., Jr., Whetten, J. T., Waitt, R. B., Swanson, D. A., Byerly, G. R., Booth, D. B., Hetherington, M. J., Zartman, R. E., 1987, Geologic Map of the Chelan 30-Minute by 60-Minute Quadrangle, Washington: U. S. Geological Survey Miscellaneous Investigations Series Map I-1661, scale 1:100,000. [http://pubs.er.usgs.gov/publication/i1661] Tabor, R. W., Waitt, R. B., Jr., Frizzell, V. A., Jr., Swanson, D. A., Byerly, G. R., Bentley, R. D., 1982, Geologic Map of the Wanatchee 1:100,000 Quadrangle, Central Washington: U. S. Geological Survey Miscellaneous Investigations Series Map I-1311, scale 1:100,000. [http://pubs.er.usgs.gov/publication/i1311] Southwick, D. L., 1974, Geology of the Alpine-type Ultramafic Complex and Mount Stuart, Washington: Geological Society of America Bulletin, v. 85, no. 3, p 391-402. 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. Hibbard, M. J., 1971, Evolution of a Plutonic Complex, Okanogan Range, Washington: Geological Society of America Bulletin, v. 82, no. 11, p. 3013-3048.
Geographic coverage	Chelan - Ferry - Kittitas - Okanogan - Skagit - Whatcom