Lower and Middle Jurassic marine rocks

Dark-gray, massive to thick-bedded, siliceous argillite, siltstone, and shale; includes minor graywacke and limestone. Confined to northwestern Whatcom County.
State Washington
Name Lower and Middle Jurassic marine rocks
Geologic age Devonian-Permian
Lithologic constituents
Metamorphic > MetasedimentaryIncludes metamorphosed sandstone, siltstone, argillite, tuff, with lesser conglomerate, chert, and limestone and marble.
Comments Relative proportions of different lithologies within metasedimentary rocks and metavolcanic rocks are unknown (Lapen, 2000, Dragovich and others, 2002)--see lithology coding for lithologies included in each category.
Stratigraphic units Chilliwack Group, undivided

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.

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.

Lapen, T.J., 2000, Geologic Map of the Bellingham 1:100,000 Quadrangle, Washington: Washington Division of Geology and Earth Resources Open File Report 2000-5, 36 p., 2 pl.

NGMDB product
Counties Whatcom