Yellowjacket Formation.

Siltite, calc-silicate rocks, argillite, and rare marble in central Idaho; stratigraphically below the Hoodoo Quartzite. (Mesoproterozoic Metasedimentary Rocks of Lemhi Subbasin of Belt Basin).
State Idaho
Name Yellowjacket Formation.
Geologic age Mesoproterozoic
Lithologic constituents
Major
Metamorphic > Metasedimentary > Metaclastic > MetasiltstoneSiltite.
Metamorphic > Metasedimentary > Calc-silicate-rock
Metamorphic > Metasedimentary > Metaclastic > Argillite
Incidental
Metamorphic > Metasedimentary > Metacarbonate > Marble
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 Custer - Lemhi - Valley