|Name||Felsic to mafic gneiss|
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).|
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.
|Counties||Berks - Bucks - Chester - Lancaster - Lebanon - Lehigh - Northampton|