Ammonoosuc Volcanics of Billings (1935) - metamorphosed andesitic and basaltic tuff, crystal tuff, and tuff breccia (VTOaa;0)

Ammonoosuc Volcanics of Billings (1935) - metamorphosed andesitic and basaltic tuff, crystal tuff, and tuff breccia

Dark-greenish-gray to medium-bluish-gray metamorphosed andesitic and basaltic tuff, crystal tuff, and tuff breccia; minor pillow lava. Commonly contains plagioclase and (or) altered mafic phenocrysts. Stratified rocks of the Bronson Hill arch and Sawyer Mountain belt. Stratified rocks of the Bronson Hill arch and Sawyer Mountain belt.

State	Vermont
Name	Ammonoosuc Volcanics of Billings (1935) - metamorphosed andesitic and basaltic tuff, crystal tuff, and tuff breccia
Geologic age	Upper and Middle Ordovician
Lithologic constituents	Major Metamorphic > Metaigneous > Metavolcanic > MetaandesiteDark-greenish-gray to medium-bluish-gray metamorphosed andesitic and basaltic tuff, crystal tuff, and tuff breccia; minor pillow lava. Commonly contains plagioclase and (or) altered mafic phenocrysts. Metamorphic > Metaigneous > Metavolcanic > MetabasaltDark-greenish-gray to medium-bluish-gray metamorphosed andesitic and basaltic tuff, crystal tuff, and tuff breccia; minor pillow lava. Commonly contains plagioclase and (or) altered mafic phenocrysts.
References	Ratcliffe, N.M., Stanley, R.S., Gale., M.H., Thompson, P.J., and Walsh, G.J., 2011, Bedrock geologic map of Vermont: U.S. Geological Survey Scientific Investigations Map 3184, 3 sheets, scale 1:100,000. https://pubs.er.usgs.gov/publication/sim3184
NGMDB product	NGMDB product page for 96860
Counties	Essex - Orange - Windsor

Ammonoosuc Volcanics of Billings (1935) - metamorphosed andesitic and basaltic tuff, crystal tuff, and tuff breccia

Ratcliffe, N.M., Stanley, R.S., Gale., M.H., Thompson, P.J., and Walsh, G.J., 2011, Bedrock geologic map of Vermont: U.S. Geological Survey Scientific Investigations Map 3184, 3 sheets, scale 1:100,000.