| State | Pennsylvania |
|---|---|
| Name | Conestoga Formation |
| Geologic age | Ordovician and Cambrian |
| Lithologic constituents |
Major
Sedimentary > Carbonate > Limestone (Bed)Light-gray, thin-bedded, impure, contorted limestone; in Chester Valley, includes micaceous limestone in upper part, phyllite in middle, and alternating dolomite and limestone in lower part
Minor
Metamorphic > Metasedimentary > Metaclastic > Phyllitein Chester Valley, includes micaceous limestone in upper part, phyllite in middle, and alternating dolomite and limestone in lower part.
Sedimentary > Clastic > Conglomerate (Bed)conglomeratic at base
Sedimentary > Carbonate > Dolostone (Bed)in Chester Valley, includes micaceous limestone in upper part, phyllite in middle, and alternating dolomite and limestone in lower part.
Incidental
Sedimentary > Clastic > Mudstone > Shale (Bed)contorted limestone having shale partings
|
| 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 - Chester - Delaware - Lancaster - Montgomery - Philadelphia - York |