Miner Creek and Cokedale Formations

Livingston Group. Miner Creek: Alternating beds of olive gray tuffaceous siltstone and greenish gray volcaniclastic sandstone, silicified tuff, and bentonite. Sulphur Flats Member (lower part of formation): massive, cross-bedded, poorly sorted sandstone. Inland coastal plain. Thickness as much as 410 m (1,345 ft). Cokedale Formation: Olive gray, tuffaceous siltstone, dusky yellowish green and light gray, volcaniclastic-rich sandstone, grayish brown mudstone, water-laid tuff, bentonite, and carbonaceous claystone; coal in lower part. Transitional inland coastal plain to brackish. Thickness as much as 790 m (2,592 ft).
State Montana
Name Miner Creek and Cokedale Formations
Geologic age Cretaceous
Lithologic constituents
Major
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Siltstone (Bed, Tuffaceous)
Minor
Sedimentary > Clastic > Mudstone (Bed)
Sedimentary > Clastic > Mudstone > Claystone > Bentonite (Bed, Carbonaceous)
Incidental
Sedimentary > Coal
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 - Park