Fort Ann Formation (VTOfa;0)

Fort Ann Formation

(Shown only in New York State). Medium- to dark-gray and mottled, medium- to thick-bedded dolomitic limestone and buff-weathering dolostone. Part of the Beekmantown Group. Rocks of the Laurentian Margin. Part of the Adirondack lowlands and Lake Champlain lowlands (west of the Orwell and Champlain thrusts).

State	Vermont
Name	Fort Ann Formation
Geologic age	Lower Ordovician
Lithologic constituents	Major Sedimentary > Carbonate > Limestone (Bed)Medium- to dark-gray and mottled, medium- to thick-bedded dolomitic limestone. Sedimentary > Carbonate > Dolostone (Bed)Medium- to dark-gray and mottled, medium- to thick-bedded dolomitic limestone and buff-weathering dolostone.
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	Rutland

Fort Ann Formation

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.