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Mineral Resources On-Line Spatial Data

Triassic sedimentary rocks, undivided

Predominantly limestone, marble, and dolomite near Riverside in Okanogan County. Conglomerate, shale, graywacke, gritstone, and limestone on San Juan Island. Siltstone with greenstone locally on Orcas Island. Graywacke conglomerate, cherty greenstone, and limestone in northern Ferry County.
StateWashington
NameTriassic sedimentary rocks, undivided
Geologic ageTriassic with Permian where impossible to differentiate
Original map labelTR
CommentsLimestone and dolomite in Asotin County (Martin Bridge Limestone). San Juan Islands consist mostly of metasedimentary rocks (see lithology coding).
Primary rock typelimestone
Secondary rock typedolostone (dolomite)
Other rock typesmetasedimentary rock; marble; conglomerate; slate; sandstone; siltstone; greenstone; chert; argillite
Lithologic constituents
Major
Sedimentary > Carbonate > Limestone (Bed)
Minor
Metamorphic > MetasedimentaryIncludes meta-argillite, metasandstone, metaconglomerate, metachert, and metamudstone, mostly on San Juan Islands (Dragovich and others, 2002).
Sedimentary > Carbonate > Dolostone (Bed)
Incidental
Metamorphic > Argillite
Sedimentary > Chemical > Chert (Bed)
Sedimentary > Clastic > Siltstone (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Metamorphic > Slate
Sedimentary > Clastic > Conglomerate (Bed)
Metamorphic > Marble
Sedimentary > Carbonate > Limestone (Lense)
Metamorphic > Greenstone (Greenschist)Are tuffs, flows or intrusives depending on original rock (Parker and Calkins, 1964).
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.
Parker, R. L. and Calkins, J. A., 1964, Geology of the Curlew Quadrangle Ferry County Washington, U.S. Geological Survey Bulletin 1169, 95 p.
Reidel, S. P., Hooper, P. R., Webster, G. D., Camp, V. E., 1992, Geologic Map of Southeastern Asotin County, Washington: Washington Division of Geology and Earth Resources Geologic Map GM-40, scale 1:48,000.
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.
Rinehart, C. D., and Fox, K. F., Jr., 1976, Bedrock Geology of the Conconully Quadrangle, Okanogan County, Washington: U. S. Geological Survey Bulletin 1402, 58 p.
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.
Geographic coverageAsotin - Ferry - Okanogan - San Juan

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