Conemaugh Formation

Includes the rocks between the base of the Pittsburgh coal and the top of the Upper Freeport coal; consists of two unnamed members which are separated by the Barton coal; both members are gray and brown claystone, shale, siltstone and sandstone, with several coal beds; lower member also contains redbeds and fossiliferous marine shales; thickness 825 to 925 feet.
State Maryland
Name Conemaugh Formation
Geologic age Pennsylvanian
Lithologic constituents
Sedimentary > Clastic > Mudstone > Shale
Sedimentary > Clastic > Mudstone > Claystone
Sedimentary > Clastic > Sandstone
Sedimentary > Clastic > Siltstone
Sedimentary > Coal

Cleaves, E.T., Edwards, J., Jr., and Glaser, J.D., 1968, Geologic Map of Maryland: Maryland Geological Survey, Baltimore, Maryland, scale 1:250,000.

In 1995 the Water Resources Division of the U.S. Geological Survey digitized the geologic map of Maryland from the 1968 paper map (Reference MD001). Information about products from the Maryland Geological Survey can be found at

NGMDB product
Counties Allegany - Garrett