Washington Gneiss

Coarse- to medium-grained hornblende-garnet amphibolite, hornblende-plagioclase gneiss and phlogopite-hornblende-plagioclase amphibolite (metabasalt).
State Massachusetts
Name Washington Gneiss
Geologic age Proterozoic Y
Lithologic constituents
Major
Metamorphic > AmphiboliteCoarse- to medium-grained hornblende-garnet amphibolite, and phlogopite-hornblende-plagioclase amphibolite (metabasalt).
Minor
Metamorphic > Metaigneous > Metavolcanic > Metabasaltphlogopite-hornblende-plagioclase amphibolite (metabasalt)
Metamorphic > Gneiss > Hornblende-gneisshornblende-plagioclase gneiss
Comments Part of Taconic-Berkshire Zone (Ordovician and Older Rocks); in Berkshire Highlands and Green Mountain Core
References
NGMDB product
Counties Berkshire - Hampden