|Name||Copake and Halcyon Lake Formations, Rochdale Limestone|
|Geologic age||Lower Ordovician|
|Comments||part of Beekmantown and Stockbridge Groups, Potsdam Sandstone, and Vermont Valley Sequence up to 3500 ft. (1100 m). Note that unit has no name on printed map, (part of Wappinger Group - inferred from other map sheets). Used formations for unit name here.|
|Primary rock type||limestone|
|Secondary rock type||dolostone (dolomite)|
|Other rock types||chert|
Sedimentary > Carbonate > Limestone
Sedimentary > Carbonate > Dolostone (Calcareous)
Sedimentary > Chemical > ChertHalcyon Lake Formation-chert
NYS Museum, NYS Geological Survey, NYS Museum Technology Center, 1999, 1:250,000 Bedrock geology of NYS, data is distributed in ARC/INFOr EXPORT format (with ".e00" extension) in 5 seperate files based on printed map sheets, http://www.nysm.nysed.gov/gis.html.
D. W. Fisher; Y. W. Isachsen, L. V. Rickard, 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 1:250000.
|Counties||Columbia - Dutchess - Orange|