Martinsburg Formation

Dark-gray, slaty to phyllitic shale, calcareous at base. Probably only lower part of Martinsburg Formation is present; overlain by Hamburg sequence rocks.
State Pennsylvania
Name Martinsburg Formation
Geologic age Ordovician
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Shale (Calcareous)dark-gray, slaty to phyllitic shale, calcareous at base
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 Berks - Lancaster - Lebanon - Lehigh