| State | Pennsylvania |
|---|---|
| Name | Felsic to mafic gneiss |
| Geologic age | Precambrian |
| Lithologic constituents | Major
Metamorphic > Gneissfelsic to mafic gneiss - light, medium grained; predominantly quartz and feldspar of igneous origin.
|
| Comments | Digital map differences from 1980 printed map: name changed from (Granitic gneiss). |
| 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 - Lancaster - Lebanon - Lehigh - Northampton |