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Iberville Formation

Iberville Formation - Noncalcareous black shale interbedded with occasional dolomite beds and in the lower part with calcareous shale.
State Vermont
Name Iberville Formation
Geologic age Ordovician
Comments Part of Champlain and Vermont Valleys, Trenton Group
Primary rock type black shale
Secondary rock type dolostone (dolomite)
Other rock types
Lithologic constituents
Sedimentary > Clastic > Mudstone > Shale (Bed)Noncalcareous black shale; lower part with calcareous shale
Sedimentary > Carbonate > Dolostone (Bed)
Map references
Nicholson, S.W., Dicken, C.L., Horton, J.D., Foose, M.P., Mueller, J.A.L., and Hon, Rudi, 2006, Preliminary integrated geologic map databases for the United States: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, Rhode Island, and Vermont: U.S. Geological Survey Open-File Report 2006-1272.
Unit references
Doll, C.G., Cady, W.M., Thompson, J.B., Jr., and Billings, M.P., 1961, Centennial Geologic Map of Vermont: Vermont Geological Survey, Miscellaneous Map MISCMAP-01, scale 1:250,000.
Counties Addison - Chittenden - Franklin - Grand Isle