Estill Shale and Drowning Creek Formation, Undivided

Estill Shale, reddish to greenish gray, weathers light gray, minor interbedded dolomite, planar to irregular bedding, thin to thick bedded, 30 to 180 feet thick. Forms unstable slopes susceptible to landslides. Drowning Creek Formation; dolomite with minor shale; bluish gray to gray weathers yellowish orange; argillaceous and silty in part; planar to lenticular, thin to thick bedded; 20 to 90 feet thick.
State Ohio
Name Estill Shale and Drowning Creek Formation, Undivided
Geologic age Silurian
Lithologic constituents
Major
Sedimentary > Carbonate > Dolostone (Bed)Estill Shale: minor interbedded dolomite. Drowning Creek Formation: dolomite, bluish gray to gray weathers yellowish orange; argillaceous and silty in part; planar to lenticular, thin to thick bedded; 20 to 90 feet thick.
Sedimentary > Clastic > Mudstone > Shale (Bed)Estill Shale: reddish to greenish gray, weathers light gray, planar to irregular bedding, thin to thick bedded, 30 to 180 feet thick. Drowning Creek Formation: minor shale.
References

Slucher, E.R., (principal compiler), Swinford, E.M., Larsen, G.E., and others, with GIS production and cartography by Powers, D.M., 2006, Bedrock geologic map of Ohio: Ohio Division of Geological Survey Map BG-1, version 6.0, scale 1:500,000.

NGMDB product
Counties Adams