Lockatong Formation

Dark-gray to black, thick-bedded argillite containing a few zones of thin-bedded black shale; locally has thin layers of impure limestone and calcareous shale.
State Pennsylvania
Name Lockatong Formation
Geologic age Triassic
Lithologic constituents
Major
Metamorphic > Metasedimentary > Metaclastic > ArgilliteDark-gray to black, thick-bedded argillite.
Minor
Sedimentary > Carbonate > Limestone (Bed)Locally has thin layers of impure limestone and calcareous shale.
Sedimentary > Clastic > Mudstone > Shale (Bed, Calcareous)Locally has thin layers of impure limestone and calcareous shale.
Incidental
Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed)Dark-gray to black, thick-bedded argillite containing a few zones of thin-bedded black shale.
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 - Bucks - Chester - Montgomery