Quinebaug Formation

Medium- to dark-gray, commonly greenish, medium-grained, well-layered gneiss, composed of hornblende, andesine, biotite, and epidote, commonly with quartz or garnet, interlayered with amphibolite.
State Connecticut
Name Quinebaug Formation
Geologic age Middle Ordovician or older
Lithologic constituents
Major
Metamorphic > GneissMedium- to dark-gray, commonly greenish, medium-grained, well-layered gneiss, composed of hornblende, andesine, biotite, and epidote, commonly with quartz or garnet.
Minor
Metamorphic > Amphibolite
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 New London - Windham