Bluebird Mountain through South Creek: Bluebird Mountain, Railroad Canyon, Surrett Canyon, and South Creek Formations

Bluebird Mountain Formation: Medium gray to brownish gray quartzite interbedded with yellowish brown, very fine-grained sandstone, gray calcareous siltstone, and medium-gray sandy limestone. Marine. Thickness 275 m (902 ft). Railroad Canyon Formation: Medium gray and brownish black, phosphatic mudstone, shale, limestone, limestone conglomerate, and medium gray sandstone. Marine. Thickness 260 m (853 ft). Surrett Canyon Formation: Dark gray, massive limestone with much scattered white bioclastic debris. Marine. Thickness at type section 67 m (220 ft). South Creek Formation: Dark gray, thin-bedded, chert bearing limestone that alternates with dark gray, argillaceous limestone. Marine. Thickness at type section 91 m (300 ft).
State Montana
Name Bluebird Mountain through South Creek: Bluebird Mountain, Railroad Canyon, Surrett Canyon, and South Creek Formations
Geologic age Pennsylvanian and Mississippian
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Shale > Phosphatic-shale (Bed)
Metamorphic > Metasedimentary > Metaclastic > Quartzite
Sedimentary > Carbonate > Limestone (Bed)
Minor
Sedimentary > Clastic > Conglomerate (Bed)
Sedimentary > Clastic > Siltstone (Bed, Calcareous)
Sedimentary > Clastic > Sandstone (Bed)
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 Beaverhead