Foliated granitic gneiss

Light-gray, coarse-grained, strongly to weakly foliated gneiss, composed of phenocrysts of K-feldspar in a groundmass of plagioclase, quartz, K-feldspar, and biotite, with accessory sillimanite and garnet.
State Connecticut
Name Foliated granitic gneiss
Geologic age Devonian?
Lithologic constituents
Major
Metamorphic > Gneiss > Biotite-gneissLight-gray, coarse-grained, strongly to weakly foliated gneiss, composed of phenocrysts of K-feldspar in a groundmass of plagioclase, quartz, K-feldspar, and biotite, with accessory sillimanite and garnet.
Comments Part of Eastern Uplands; Iapetus (Oceanic) Terrane - Merrimack Synclinorium
References

Rodgers, John, compiler, 1985, Bedrock Geological Map of Connecticut: Connecticut Geological and Natural History Survey, Hartford, Connecticut, 2 sheets, scale 1:125,000.

NGMDB product
Counties Tolland