Washington Gneiss

Rusty-weathering, muscovite-biotite-sillimanite and/or kyanite-garnet schist; blue-quartz ribbed conglomerate, interlayered garnet-plagioclase-quartz metadacite.
State Massachusetts
Name Washington Gneiss
Geologic age Proterozoic Y
Lithologic constituents
Major
Metamorphic > Schist > Mica-schistmuscovite-biotite-sillimanite and/or kyanite-garnet schist
Minor
Metamorphic > Metaigneous > Metavolcanic > Metadaciteinterlayered garnet-plagioclase-quartz metadacite
Sedimentary > Clastic > Conglomerateblue-quartz ribbed conglomerate
Comments Part of Taconic-Berkshire Zone (Ordovician and Older Rocks); in Berkshire Highlands and Green Mountain Core
References
NGMDB product
Counties Berkshire - Hampden - Hampshire