Copake and Rochdale Formations

Copake Formation-limestone, dolostone, siltstone; Rochdale Formation-limestone, dolostone; Halcyon Lake Dolostone-locally cherty.
State New York
Name Copake and Rochdale Formations
Geologic age Lower Ordovician
Lithologic constituents
Major
Sedimentary > Carbonate > Limestone
Minor
Sedimentary > Clastic > SiltstoneCopake Formation
Sedimentary > Carbonate > Dolostone
Incidental
Sedimentary > Chemical > ChertHalcyon Lake Dolostone-locally cherty.
Comments part of Wappinger and Stockbridge Groups, Poughquag Quartzite, and Metamorphic Equivalents up to 4000 ft. (1200 m).
References

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.

NGMDB product
Counties Columbia - Dutchess - Orange