Theresa Formation

Dolostone, sandstone (Chateauguay in Quebec).
State New York
Name Theresa Formation
Geologic age Cambrian - Lower Ordovician
Lithologic constituents
Sedimentary > Carbonate > Dolostone
Sedimentary > Clastic > Sandstone
Comments part of Beekmantown Group, Potsdam Sandstone, and Vermont Valley Sequence up to 2500 ft. (760 m). Secondary unit description from USGS Geologic Names lexicon (ref. NY046): Named Theresa formation in central and eastern NY. Consists of somewhat calcareous, sandy dolomites with interbedded weak sandstones, especially near base. Thickness is 20 to 70 feet. Very closely related to underlying Potsdam sandstone and formerly included in Potsdam but here separated as distinct formation. Base drawn at base of first dolomite layer. Unconformably underlies the Pamelia limestone (of Chazy age) in Theresa and Alexander Bay quadrangles, Jefferson County. The Theresa is of Late Cambrian age.

Fisher, D.W., Isachsen, Y.W., and Rickard, L.V., 1970, Geologic Map of New York State, consisting of 5 sheets: Niagara, Finger Lakes, Hudson-Mohawk, Adirondack, and Lower Hudson, New York State Museum and Science Service, Map and Chart Series No. 15, scale 1:250,000.

USGS Geologic Names lexicon found at:

NGMDB product
Counties Clinton - Franklin - Jefferson - Lewis - Saint Lawrence