Rockdale Run Formation

Mostly limestone; some dolomite interbeds; some chert near middle and top; stromatolitic limestone in middle; pinkish marbleoid limestone and chert at base.
State Pennsylvania
Name Rockdale Run Formation
Geologic age Ordovician
Lithologic constituents
Major
Sedimentary > Carbonate > Limestone (Bed)mostly limestone; stromatolitic limestone in middle; pinkish marbleoid limestone and chert at base.
Minor
Sedimentary > Carbonate > Dolostone (Bed)
Sedimentary > Chemical > Chert (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 Cumberland - Dauphin - Franklin - Fulton