Washington Gneiss

Well-layered, rusty-tan weathering muscovite-biotite plagioclase-microcline-quartz granofels containing layers of rusty sulfidic calc-silicate rocks.
State Massachusetts
Name Washington Gneiss
Geologic age Proterozoic Y
Lithologic constituents
Major
Metamorphic > Granoblastic > Granofelsmuscovite-biotite plagioclase-microcline-quartz granofels
Metamorphic > Metasedimentary > Calc-silicate-rockcontaining layers of rusty sulfidic calc-silicate rocks
Comments Part of Taconic-Berkshire Zone (Ordovician and Older Rocks); in Berkshire Highlands and Green Mountain Core
References
NGMDB product
Counties Berkshire - Hampden