Swauger and Lawson Creek formations.

Quartzose medium- to coarse-grained quartzite of Swauger Formation and siltite and quartzite of overlying Lawson Creek Formation in east-central Idaho. (Mesoproterozoic Metasedimentary Rocks of Lemhi Subbasin of Belt Basin).
State Idaho
Name Swauger and Lawson Creek formations.
Geologic age Mesoproterozoic
Lithologic constituents
Major
Metamorphic > Metasedimentary > Metaclastic > MetasiltstoneSiltite.
Metamorphic > Metasedimentary > Metaclastic > QuartziteQuartzose medium- to coarse-grained quartzite.
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 Butte - Custer - Lemhi