Biotite granitic gneiss

Biotite granitic gneiss.
State Massachusetts
Name Biotite granitic gneiss
Geologic age Devonian
Lithologic constituents
Major
Metamorphic > Gneiss > Biotite-gneissBiotite granitic gneiss.
Comments Part of Connecticut Valley Belt (Silurian and Devonian Rocks); mainly small lenses in Merrimack Belt (probably mostly Devonian, but may be older in part); age uncertain, probably mostly Devonian, but may be older in part.
References
NGMDB product
Counties Franklin - Hampden - Worcester