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Garnet-mica schist, gneiss, and quartzite; Proterozoic high-grade metasedimentary rocks; trans-Idaho metamorphic province

Precambrian high-grade metamorphic rock; metasediment; Kyanite-sillimanite-garnet-mica schist and gneiss; minor quartzite
State Idaho
Name Garnet-mica schist, gneiss, and quartzite; Proterozoic high-grade metasedimentary rocks; trans-Idaho metamorphic province
Geologic age Late to Early Proterozoic
Comments ZXmhs (originally PC1) includes high-grade metasedimentary rocks of the Elk City and Syringa metamorphic series (ID185), undivided. The Elk City metamorphic series is similar to Y3smh biotite gneiss, interpreted as metamorphosed Apple Creek Fm (ID025), and is intruded by augen gneiss (Yifm). Detrital zircons from various Syringa-series samples indicate Belt-age, pre-Belt, and post-Belt components (Reed S. Lewis, oral commun., 2004).
Primary rock type mica schist
Secondary rock type paragneiss
Other rock types quartzite; orthogneiss
Lithologic constituents
Major
Metamorphic > Schist (Amphibolite)coarse biotite schist +/- garnet +/- sillimanite +/- kyanite
Metamorphic > Gneiss (Amphibolite)quartzo-feldspathic biotite paragneiss
Minor
Metamorphic > Quartzite (Amphibolite)minor quartzite, interlayered with biotite schist and gneiss
Incidental
Metamorphic > Gneiss (Amphibolite)incidental augen-bearing granitoid orthogneiss
Map references
Bond, J.G., Kauffman, J.D., Miller, D.A., and Venkatakrishnan, Ramesh, 1978, Geologic map of Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, with contributions from U.S. Geological Survey, scale 1:500,000.
Unit references
Bond, J.G., Kauffman, J.D., Miller, D.A., and Venkatakrishnan, Ramesh, 1978, Geologic map of Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, with contributions from U.S. Geological Survey, scale 1:500,000.
Lewis, R.S., Burmeister, R.F., Bennett, E.H., and White, D.L., 1990, Preliminary geologic map of the Elk City region, Idaho: Moscow, Idaho, Idaho Geological Survey Technical Report 90-2, scale 1:100,000 with pamphlet, 5 p.
Evans, K.V. and Green, G.N., 2003, Geologic map of the Salmon National Forest and vicinity, east-central Idaho: U.S. Geological Survey Geological Investigations Series I-2765, scale 1:100,000 with pamphlet, 19 p.
Mitchell V.E.. and Bennett, E.H., 1979, Geologic map of the Elk City quadrangle, Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, Geologic Map Series, Elk City 2o Quadrangle, scale 1:250,000.
Lewis, R.S., Burmester, R.F., McFadden, M.D., Derkey, P.D., and Oblad, J.R., 1999, Digital geologic map of the Wallace 1:100,000 quadrangle, Idaho: U.S. Geological Survey Open-File Report 99-390, with pamphlet 46 p.
Rember, W.C., and Bennett, E.H., 1979, Geologic map of the Hamilton quadrangle, Idaho: Moscow, Idaho, Idaho Bureau of Mines and Geology, Geologic Map Series, Hamilton 2o quadrangle, 1:250,000 scale.
Lewis, R.S., Burmester, R.F., and Bennett, E.H., 1997, Metasedimentary rocks between the Bitterroot and Atlanta lobes of the Idaho batholith and their relationship to the Belt Supergroup: in Berg, R.B., ed., Belt Symposium III, 1993: Montana Bureau of Mines and Geology, Special Publication 112, p. 130-144.
Counties Clearwater - Idaho - Shoshone