Cannonball Formation

Gray and tan siltstone, sandy to silty claystone, and fine-grained, calcareous clayely to silty sandstone, and abundant, round to lenticular carbonate concretions. Thickness up to 180 ft (55 m).
State South Dakota
Name Cannonball Formation
Geologic age Paleocene
Lithologic constituents
Sedimentary > Clastic > Siltstone (Bed)
Sedimentary > Clastic > Mudstone > Claystone (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Carbonate (Lens)abundant round to lenticular carbonate concretions

Martin, J.E., Sawyer, J.F., Fahrenbach, M.D., Tomhave, D.W., and Schulz, L.D., 2004, Geologic Map of South Dakota: South Dakota Geological Survey, GM 10, scale 1:500,000.

NGMDB product
Counties Corson - Harding - Perkins