Graphitic felsic gneiss

Includes Pickering Gneiss and small areas of marble; dominantly quartz and feldspar with varying amounts of graphite and various metamorphic minerals; medium grained, light to dark gray and greenish gray; sedimentary origin.
State Pennsylvania
Name Graphitic felsic gneiss
Geologic age Precambrian
Lithologic constituents
Major
Metamorphic > Gneissgraphitic felsic gneiss - includes Pickering Gneiss and small areas of marble; dominantly quartz and feldspar with varying amounts of graphite and various metamorphic minerals; medium grained, light to dark gray and greenish gray; sedimentary origin.
Minor
Metamorphic > Metasedimentary > Paragneissgraphitic felsic gneiss - includes Pickering Gneiss and small areas of marble; dominantly quartz and feldspar with varying amounts of graphite and various metamorphic minerals; medium grained, light to dark gray and greenish gray; sedimentary origin.
Metamorphic > Metasedimentary > Metacarbonate > Marblesmall areas of marble
Comments Digital map differences from 1980 printed map: name changed from (Graphitic 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 - Chester - Lancaster - Lebanon