Claggett Formation

Dark gray to gray shale that weathers brown, with thin, gray sandstone laminae and beds in upper or middle part and calcareous concretions in lower part. Marine. Thickness as much as 170 m (558 ft).
State Montana
Name Claggett Formation
Geologic age Cretaceous
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Shale (Bed, Calcareous)
Minor
Sedimentary > Clastic > Sandstone (Bed, Calcareous)
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 Big Horn - Blaine - Carbon - Chouteau - Fergus - Garfield - Golden Valley - Hill - Judith Basin - Liberty - Meagher - Musselshell - Petroleum - Phillips - Rosebud - Stillwater - Toole - Valley - Wheatland - Yellowstone