Ravalli Group.

Feldspathic quartzite and subordinate siltite and argillite of the Burke, Revett, and St. Regis formations in northern Idaho; south of St. Joe River, includes correlative garnet-grade quartzite and schist. (Mesoproterozoic Belt Supergroup).
State Idaho
Name Ravalli Group.
Geologic age Mesoproterozoic
Lithologic constituents
Major
Metamorphic > Metasedimentary > Metaclastic > QuartziteFeldspathic quartzite and garnet-grade quartzite.
Minor
Metamorphic > Metasedimentary > Metaclastic > Argillite
Metamorphic > Metasedimentary > Metaclastic > MetasiltstoneSiltite.
Metamorphic > Schist
References

Lewis, Reed S., Link, Paul K., Stanford, Loudon R., and Long, Sean P., Geologic Map of Idaho, 2012, Idaho Geological Survey, Geologic Map 9 (M-9); Scale 1:500,000.

NGMDB product
Counties Benewah - Bonner - Boundary - Clearwater - Idaho - Kootenai - Latah - Shoshone