Silurian-Devonian rocks

Mainly black argillite; some limestone, thin beds of conglomerate, sandstone, quartzite, and dolomite. Rocks confined to northwestern Pend Oreille County and adjacent Stevens County. Silurian age based on Monograptus and corals of several unusual genera; Devonian age based on coral fauna.
State Washington
Name Silurian-Devonian rocks
Geologic age Silurian-Devonian
Lithologic constituents
Metamorphic > MetasedimentaryIncludes siltstone, argillite, limestone, and packstone--relative abundances unknown.
Sedimentary > Clastic > Conglomerate (Bed)
Metamorphic > Metasedimentary > Metaclastic > SlateInterbedded with conglomerate.
Comments This unit mapped as Ledbetter Slate by Park and Cannon, 1943; mapped as separate units by Joseph, 1990a.
Stratigraphic units Ledbetter Slate (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.

Park, C.F.Jr., and Cannon, R.S.Jr., 1943, Geology and Ore Deposits of the Metaline Quadrangle, Washington: U. S. Geological Survey Professional Paper 202, 81 p.

Joseph, N.L., 1990a, Geologic Map of the Colville 1:100,000 Quadrangle, Washington-Idaho: Washington Division of Geology and Earth Resources Open File Report 90-13, 78 p., 1 pl.

NGMDB product
Counties Pend Oreille