Harpers Formation

Dark-greenish-gray phyllite and schist containing thin quartzite layers; includes Montalto Member (CAhm).
State Pennsylvania
Name Harpers Formation
Geologic age Cambrian
Lithologic constituents
Major
Metamorphic > Metasedimentary > Metaclastic > Phyllite
Metamorphic > Schist
Minor
Metamorphic > Metasedimentary > Metaclastic > Quartzite
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 Adams - Cumberland - Franklin