Massie and Osgood Shales; Dayton and Brassfield Limestones; Laurel Dolomite; Undivided

Massie Shale; gray to bluish gray; planar to irregular, thin to thick bedded; calcareous; slakes; minor limestone and dolomite beds; 0 to 10 feet thick. Laurel Dolomite; gray to tan, weathers brown; argillaceous to nonargillaceous; wavy, thin to medium bedded; 5 to 10 feet thick. Osgood Shale, blue gray to gray weathers brown; thin to massive bedded; calcareous with minor limestone and dolomite; slakes and slumps readily in outcrop; 3 to 25 feet thick. Dayton Limestone; gray to bluish-gray weathers grayish-white; medium to thick bedded; fine grained; dolomitic; 5 to 15 feet thick. Brassfield Limestone; white to pink, locally gray to reddish brown; irregular, thin to medium bedded; coarsely crystalline; abundant pelmatozoan fossils; grayish-green glauconitic partings; cliff forming; 20 to 50 feet thick. Interval ranges from 32 to 100 feet in thickness.
State Ohio
Name Massie and Osgood Shales; Dayton and Brassfield Limestones; Laurel Dolomite; Undivided
Geologic age Silurian
Lithologic constituents
Major
Sedimentary > Carbonate > Limestone (Bed)Massie: minor limestone. Osgood: minor limestone. Dayton Limestone; gray to bluish-gray weathers grayish-white; medium to thick bedded; fine grained; dolomitic; 5 to 15 feet thick. Brassfield Limestone; white to pink, locally gray to reddish brown; irregular, thin to medium bedded; coarsely crystalline; abundant pelmatozoan fossils; grayish-green glauconitic partings.
Minor
Sedimentary > Carbonate > Dolostone (Bed)Massie: minor dolomite. Osgood: minor dolomite. Dayton: dolomitic. Laurel Dolomite: gray to tan, weathers brown; argillaceous to nonargillaceous; wavy, thin to medium bedded; 5 to 10 feet thick.
Sedimentary > Clastic > Mudstone > Shale (Bed, Calcareous)Massie: gray to bluish gray; planar to irregular, thin to thick bedded; calcareous; slakes; 0 to 10 feet thick. Osgood: blue gray to gray weathers brown; thin to massive bedded; calcareous; slakes and slumps readily in outcrop; 3 to 25 feet thick.
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 Champaign - Clark - Greene - Madison - Montgomery - Warren