Biotite-quartz-oligoclase gneiss

White- to light-gray-weathering, light- to medium-gray or greenish-gray, fine- to coarse-grained, massive to moderately well layered, foliated gneiss composed of oligoclase or andesine, quartz, biotite, and, locally, garnet. Commonly interlayered with amphibolite.
State New Jersey
Name Biotite-quartz-oligoclase gneiss
Geologic age Middle Proterozoic
Lithologic constituents
Major
Metamorphic > Gneiss > Biotite-gneissWhite- to light-gray-weathering, light- to medium-gray or greenish-gray, fine- to coarse-grained, massive to moderately well layered, foliated gneiss composed of oligoclase or andesine, quartz, biotite, and, locally, garnet.
Minor
Metamorphic > Amphibolite
References

Dalton, R.F., Herman, G.C., Monteverde, D.H., Pristas, R.S., Sugarman, P.J., and Volkert, R.A., 1999, New Jersey Department of Environmental Protection, Bedrock Geology and Topographic Base Maps of New Jersey: New Jersey Geological Survey CD Series CD 00-1; ARC/INFO (v. 7.1), scale 1:100,000.

Drake, Avery A. Jr.,Volkert, Richard, A., Monteverde, Donald H., Herman, Gregory C., Houghton,Hugh F., Parker, Ronald A., and Dalton, Richard F., 1996, Bedrock Geologic Map of Northern New Jersey: U.S. Geological Survey Miscellanenous Investigations Map I-2540-A, 4 cross sections, 2 sheets, size 56x40; 58x41, scale 1:100.000.

https://pubs.er.usgs.gov/publication/i2540A

NGMDB product
Counties Bergen - Hunterdon - Morris - Passaic - Sussex - Warren