Cambrian limestone and dolomite (WACAls;0)

Mostly massive dolomite, with a basal unit of gray to dark-gray limestone interbedded with limy shale, and an upper unit of fine-grained massive limestone with some marble; Pend Oreille and northern and central Stevens Counties. Three-fold division less evident in Colville area. Dolomite, with minor basal unit of interbedded limestone and phyllite in the Addy-Dunn Mountain area of Stevens County. Marble, dolomite, limestone, and limy slate in Hunters' district. Dolomitic marble in southern Stevens and northern Lincoln Counties. Middle Cambrian fossils near base in Metaline district, and Bathyuriscus-Elrathina fauna in lower unit in Leadpoint district. Phosphatic brachiopods in upper unit in Leadpoint district tentatively assigned to Middle and Upper Cambrian.

State	Washington
Name	Cambrian limestone and dolomite
Geologic age	Early Cambrian-Middle Ordovician
Original map label	Cls
Comments	This unit includes Devonian Limestone as mapped by Park and Cannon (1943), though they make the disclaimer that the outcrop may actually be Cambrian. Even though the source description reports that most of this unit is dolomite, referenced sources for listed stratigraphic units report that limestone with dolomitization is most prevalent in some localities. Mapped as metasedimentary (metalimestone, metadolostone, meta-argillite, and metasiltite) by Stoffel and others, 1991. Stoffel and others, 1991, report that while the term "Old Dominion limestone" was once widely used, it has since been abandoned.
Primary rock type	limestone
Secondary rock type	dolostone (dolomite)
Other rock types	shale; marble; phyllite; conglomerate; sedimentary breccia; argillite
Lithologic constituents	Major Sedimentary > Carbonate > Dolostone (Bed) Sedimentary > Carbonate > Limestone (Bed) Minor Metamorphic > Marble Incidental Metamorphic > Argillite Sedimentary > Clastic > Sedimentary-brecciaBase of Devonian Limestone as mapped by Park and Cannon (1943). Sedimentary > Clastic > Conglomerate (Bed)Base of Devonian Limestone as mapped by Park and Cannon (1943). Metamorphic > Phyllite
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. 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. [http://pubs.er.usgs.gov/publication/pp202] Weaver, C. E., 1920, The Mineral Resources of Stevens County: Washington Geological Society Bulletin No. 20, 350 p. 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. Yates, R. G., 1971, Geologic Map of the Northport Quadrangle, Washington: U. S. Geological Survey Miscellaneous Geologic Investigations Map I-603, scale 1:31,680. [http://pubs.er.usgs.gov/publication/i603]
Geographic coverage	Ferry - Lincoln - Pend Oreille - Stevens