Fox Hills Formation

Yellowish orange to gray, fine- to medium-grained, non-calcareous sandstone in upper part, and interbedded sandstone, siltstone, and black shale with calcareous concretion zone in lower part. Marginal marine. Thickness 30–45 m (98–148 ft).
State Montana
Name Fox Hills Formation
Geologic age Cretaceous
Lithologic constituents
Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed, Calcareous)
Sedimentary > Clastic > Siltstone (Bed)
Sedimentary > Clastic > Sandstone (Bed)

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 Big Horn - Blaine - Chouteau - Fergus - Garfield - Golden Valley - McCone - Musselshell - Petroleum - Phillips - Richland - Roosevelt - Rosebud - Stillwater - Sweet Grass - Treasure - Valley - Wheatland - Yellowstone