Crab Orchard Formation and Brassfield Dolomite, undivided

Crab Orchard Formation and Brassfield Dolomite, undivided; locally includes Bisher Dolomite in Estill County
State Kentucky
Name Crab Orchard Formation and Brassfield Dolomite, undivided
Geologic age Silurian
Lithologic constituents
Major
Sedimentary > Carbonate > Dolostonelithologies and lithology percentages estimated from stratigraphic column on paper source map; collectively these units are about 65% shale and 35% dolomite (some cherty)
Sedimentary > Clastic > Mudstone > Shalelithologies and lithology percentages estimated from stratigraphic column on paper source map; collectively these units are about 65% shale and 35% dolomite (some cherty)
Comments in northeastern Kentucky, thickness is 0-55 m; in east-central Kentucky, thickness is 33-57 m
References

Noger, M.C., compiler, 1988, Geologic map of Kentucky: sesquicenntennial edition of the Kentucky Geological Survey: U.S. Geological Survey and the Kentucky Geological Survey, scale 1:500,000.

NGMDB product
Counties Bath - Clark - Estill - Fleming - Garrard - Lewis - Lincoln - Madison - Mason - Montgomery - Powell - Rockcastle - Rowan