Tyringham Gneiss

Light pinkish-gray ferrohastingsite-biotite, quartz-rodded granodioritic to quartz monzonitic gneiss, coarsely porphyritic, locally having fine-grained aplitic border. Intrudes all Berkshire Proterozoic Y units.
State Massachusetts
Name Tyringham Gneiss
Geologic age Proterozoic Y
Lithologic constituents
Major
Metamorphic > GneissLight pinkish-gray ferrohastingsite-biotite, quartz-rodded granodioritic to quartz monzonitic gneiss, coarsely porphyritic, locally having fine-grained aplitic border.
Comments Part of Taconic-Berkshire Zone (Ordovician and Older Rocks)
References
NGMDB product
Counties Berkshire - Hampden