Elbrook Formation

Microcrystalline limestone and, in places, marble; includes subordinate dolomite containing abundant phyllitic layers; occurs in Chester and Montgomery Counties; relation to Elbrook of Cumberland Valley sequence is uncertain.
State Pennsylvania
Name Elbrook Formation
Geologic age Cambrian
Lithologic constituents
Major
Sedimentary > Carbonate > Limestone (Bed)microcrystalline limestone
Minor
Sedimentary > Carbonate > Dolostone (Bed)subordinate dolomite containing abundant phyllitic layers
Metamorphic > Metasedimentary > Metaclastic > Phyllitesubordinate dolomite containing abundant phyllitic layers
Incidental
Metamorphic > Metasedimentary > Metacarbonate > Marble
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 Chester - Montgomery