LaHood Formation: locally includes Table Mountain and Moose Formations in Highland Mountains

LaHood Formation: Dark gray, dark brown, reddish brown, coarse, arkosic conglomerate locally with very large clasts derived from crystalline metamorphic rocks. Grades from mega-clast conglomerate to shale or argillite over short distances. Thickness as much as 3,000 m (9,842 ft). In Highland Mountains - Table Mountain Formation: Very light gray quartzite and argillaceous quartzite. Thickness as much as 530 m (1,740 ft). Moose Formation: Silty argillite and siltite. Thickness as much as 90 m (295 ft).
State Montana
Name LaHood Formation: locally includes Table Mountain and Moose Formations in Highland Mountains
Geologic age Middle Proterozoic
Lithologic constituents
Major
Sedimentary > Clastic > Conglomerate (Bed, Arkosic)
Metamorphic > Metasedimentary > Metaclastic > Argillite
Metamorphic > Metasedimentary > Metaclastic > Quartzite
Minor
Sedimentary > Clastic > Mudstone > Shale (Bed)
Metamorphic > Metasedimentary > Metaclastic > Metasiltstonesiltite
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 Gallatin - Jefferson - Madison - Silver Bow