Upper Jurassic-Lower Cretaceous sedimentary and volcanic rocks (WAJK;0)

State	Washington
Name	Upper Jurassic-Lower Cretaceous sedimentary and volcanic rocks
Geologic age	Late Cretaceous-Jurassic
Original map label	JK
Comments	Volcanic rocks include andesite flows, tuff, and breccia with minor dacite and basalt, and minor volcaniclastic sandstone, conglomerate, and siltstone (Barksdale, 1975, Tabor and others, 1993--NOTE: Tabor and others, 1993, does not differentiate between WAJK and WAJKv). Huntting and others, 1961, originally listed"Leech River Group" in the stratigraphy of this unit; obsolete term and now considered part of Lummi and Constitution Formations (Brandon and others, 1988).
Primary rock type	andesite
Secondary rock type	sandstone
Other rock types	siltstone; slate; phyllite; greenschist; greenstone; conglomerate; black shale; argillite; chert
Lithologic constituents	Minor Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed) Sedimentary > Clastic > Conglomerate (Bed) Igneous > Volcanic > Mafic-volcanic > Andesite (Volcaniclastic, volcanic breccia) Igneous > Volcanic > Mafic-volcanic > Andesite (Flow) Sedimentary > Clastic > Sandstone (Bed) Incidental Sedimentary > Chemical > Chert (Bed) Igneous > Volcanic > Mafic-volcanic > Andesite (Pyroclastic, tuff) Metamorphic > GreenstoneMay be minor in rank. Metamorphic > Schist (Greenschist) Metamorphic > Phyllite Metamorphic > Slate Sedimentary > Clastic > Siltstone (Bed) Metamorphic > Argillite
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. 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. 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. [http://pubs.er.usgs.gov/publication/i1963] Johnson, S. Y., 1981, Stratigraphy, Sedimentology, and Paleogeographic Significance of Spieden Group, San Juan Islands, Washington: American Association of Petroleum Geologists (AAPG) Bulletin, v. 65, no. 5, p. 942. Garver, J., 1988, Stratigraphy, depositional setting, and tectonic significance of the clastic cover to the Fidalgo Ophiolite, San Juan Islands, Washington: Canadian Journal of Earth Sciences, v. 25, p. 417-432. Brandon, M. T., Cowan, D. S., Vance, J. A., 1988, The Late Cretaceous San Juan thrust system, San Juan Islands, Washington: Geological Society of America Special Paper 221, 81 p. 1 pl. Whetten, J. T., Carroll, P. I., Gower, H. D., Brown, E. H., Pessl, F., Jr., 1988, Bedrock Geologic Map of the Port Townsend 30- by 60-Minute Quadrangle, Puget Sound Region, Washington: U. S. Geological Survey Miscellaneous Investigations Series Map I-1198-G, scale 1:100,000. [http://pubs.er.usgs.gov/publication/i1198G]
Geographic coverage	Island - King - Okanogan - San Juan - Skagit - Snohomish - Whatcom