Lower Missoula Group.

Siltite, argillite, and dolomitic siltite in northern Idaho; includes Snowslip and Shepard formations, rocks previously mapped as upper member of Wallace Formation, and correlative garnet-grade phyllite and schist south of St. Joe River. Also includes schist, micaceous quartzite, and calc-silicate rocks in lower part of Meadow Creek metamorphic sequence east of Elk City, and argillite, siltite, phyllite, and calc-silicate rocks south of Lost Trail Pass. (Mesoproterozoic Belt Supergroup).
State Idaho
Name Lower Missoula Group.
Geologic age Mesoproterozoic
Lithologic constituents
Metamorphic > Metasedimentary > Metaclastic > Argillite
Metamorphic > Metasedimentary > Metaclastic > MetasiltstoneSiltite, dolomitic siltite.
Metamorphic > Metasedimentary > Calc-silicate-rock
Metamorphic > Metasedimentary > Metaclastic > QuartziteMicaceous quartzite.
Metamorphic > Schist
Metamorphic > Metasedimentary > Metaclastic > Phyllite

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 - Lemhi - Shoshone