Iberville Formation (VTOib;0)

Iberville Formation

Dark-gray shale with thin discontinuous beds of crossbedded and graded dolomitic siltstone. Rocks of the Laurentian Margin. Part of the Adirondack lowlands and Lake Champlain lowlands (west of the Orwell and Champlain thrusts).

State	Vermont
Name	Iberville Formation
Geologic age	Upper Ordovician
Lithologic constituents	Major Sedimentary > Clastic > Mudstone > Shale (Bed)Dark-gray shale. Minor Sedimentary > Clastic > Siltstone (Bed)Thin discontinuous beds of crossbedded and graded dolomitic siltstone.
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	Addison - Chittenden - Franklin - Grand Isle

Iberville 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.