Washington Gneiss

Dark-rusty-grayish-brown-weathering, graphitic garnet-plagioclase-biotite-quartz (┬▒sillimanite) schist; rusty-weathering blue-quartz-ribbed quartz schist; and garnet quartzite and rusty-weathering layers of sulfidic calc-silicate rock. Exposed in southernmost part of Green Mountain massif. Distinctive quartz ribbing decreases northward where more aluminous, less quartzofeldspathic rocks are mapped as Y2rs. Part of the aluminous schists and gneisses of the Washington Gneiss and Wilcox Formation and related rocks. Mount Holly Complex paragneiss. Rocks of the Green Mountain and Lincoln Mountain massifs and eastern domes.
State Vermont
Name Washington Gneiss
Geologic age Middle Mesoproterozoic
Lithologic constituents
Major
Metamorphic > SchistDark-rusty-grayish-brown-weathering, graphitic garnet-plagioclase-biotite-quartz (┬▒sillimanite) schist; rusty-weathering blue-quartz-ribbed quartz schist.
Minor
Metamorphic > Metasedimentary > Calc-silicate-rockRusty-weathering layers of sulfidic calc-silicate rock.
Metamorphic > Metasedimentary > Metaclastic > QuartziteGarnet quartzite.
References
NGMDB product
Counties Bennington - Windham