Lower Paleozoic rocks, undivided

Predominantly gneiss and schist in northern Ferry County. Quartzite, partly interbedded with dolomitic and calcitic marble, lime-silicate gneiss, and amphibolite; including in places forsterite marblean diopside marble, quartz-biotite-sillimanite schist and sillimanite-orthoclase gneiss in northeastern Ferry County. Quartzite with overlying limestone in southeastern Stevens County. Some upper Paleozoic and Precambrian rocks may be included.
State Washington
Name Lower Paleozoic rocks, undivided
Geologic age Paleozoic; likely Ordovician
Lithologic constituents
Metamorphic > Gneiss (Amphibolite)Includes paragneiss and orthogneiss.
Metamorphic > Schist (Amphibolite)
Metamorphic > Metasedimentary > Metaclastic > Quartzite (Amphibolite)
Metamorphic > Amphibolite (Amphibolite)
Metamorphic > Metasedimentary > Metacarbonate > Marble (Amphibolite)Possibly minor in rank.
Sedimentary > Carbonate > Limestone (Bed)
Comments Eagle Mtn Quartzite in southeastern Stevens County; difficult to distiguish from Addy or Colville Quartzites. The rest of this unit makes up part of the Tenas Mary Creek and Kettle metamorphic core complexes (see also WAPZu). Because both this unit and WAPZu contribute to these metamorphic complexes, they are likely to be of similar age. Very vague ages are reported for this unit, however (see age coding), thus the age range is very large.
Stratigraphic units Eagle Mtn Quartzite; Grand Fork Schist

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.

Weaver, C.E., 1920, The Mineral Resources of Stevens County: Washington Geological Society Bulletin No. 20, 350 p.

Stoffel, K.L., 1990, Geologic Map of the Republic 1:100,000 Quadrangle, Washington: Washington Division of Geology and Earth Resources Open File Report 90-10, 62 p, 1 pl.

NGMDB product
Counties Ferry - Okanogan - Stevens