Empire Formation

Grayish green and pale olive gray argillite and siltite with subordinate thin beds of quartzite and sandy limestone. Thickness as much as 610 m.
State Montana
Name Empire Formation
Geologic age Middle Proterozoic
Lithologic constituents
Major
Metamorphic > Metasedimentary > Metaclastic > Metasiltstonesiltite
Metamorphic > Metasedimentary > Metaclastic > Argillite
Minor
Sedimentary > Carbonate > Limestone (Bed)
Metamorphic > Metasedimentary > Metaclastic > Quartzite
References

Vuke, S.M., Porter, K.W., Lonn, J.D., and Lopez, D.A., 2007, Geologic Map of Montana - Compact Disc: Montana Bureau of Mines and Geology: Geologic Map 62-C, 73 p., 2 sheets, scale 1:500,000. This map was digitized in 2012 as a result of a contract between the U.S. Geological Survey and the Montana Bureau of Mines and Geology.

NGMDB product
Counties Broadwater - Lewis and Clark - Powell