Hamilton Group

Includes, in descending order, the Mahantango (Dmh) and Marcellus (Dmr) Formations.
State Pennsylvania
Name Hamilton Group
Geologic age Devonian
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed)
Minor
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)
Sedimentary > Clastic > Siltstone (Bed)
Incidental
Sedimentary > Clastic > Mudstone > Claystone > Bentonite (Bed)
Sedimentary > Carbonate > Limestone (Bed)
References

Berg, T.M., Edmunds, W.E., Geyer, A.R., and others, compilers, 1980, Geologic map of Pennsylvania: Pennsylvania Geological Survey, 4th ser., Map 1, 2nd ed., 3 sheets, scale 1:250,000.

Pennsylvania Bureau of Topographic and Geologic Survey, Department of Conservation and Natural Resources, Miles, C.E., and Whitfield, T.G., compilers, 2001, Bedrock Geology of Pennsylvania, edition: 1.0, digital map, scale 1:250,000.

NGMDB product
Counties Bedford - Blair - Carbon - Centre - Clinton - Columbia - Dauphin - Franklin - Fulton - Huntingdon - Juniata - Lebanon - Luzerne - Lycoming - Mifflin - Montour - Northumberland - Perry - Schuylkill - Snyder - Union