Walloomsac Formation (VTOw;0)

Walloomsac Formation

Same description as Hortonville Formation - Dark-gray siliceous shale and phyllite containing thin beds of bluish-gray argillaceous limestone and minor beds of gray to tan quartzite. Grades into limy shales of the Stony Point Formation. Tectonically shredded, silty varieties near and on Whipstock Hill constitute the Whipstock Breccia Member of Potter (1972) (Oww). Vermont Valley sequence and Middlebury synclinorium (above the Orwell and Champlain thrusts).

State	Vermont
Name	Walloomsac Formation
Geologic age	Upper Ordovician
Lithologic constituents	Major Sedimentary > Clastic > Mudstone > ShaleDark-gray siliceous shale and phyllite. Sedimentary > Carbonate > Limestone (Bed)Containing thin beds of bluish-gray argillaceous limestone. Metamorphic > Metasedimentary > Metaclastic > PhylliteDark-gray siliceous shale and phyllite. Minor Metamorphic > Metasedimentary > Metaclastic > QuartziteMinor beds of gray to tan quartzite.
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	Bennington - Rutland

Walloomsac 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.