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Valcour, Crown Point, and Day Point Limestones

Valcour, Crown Point, and Day Point Limestones - locally reefy, Ste. Therese Siltstone at base; Middlebury Limestone in Vermont; St. Martin and Rockcliffe Limestones in St. Lawrence Valley. Includes some Otbr and Obk adjacent to Champlain Thrust in Vermont.
State New York
Name Valcour, Crown Point, and Day Point Limestones
Geologic age Middle Ordovician
Comments Chazy Group 0-725 ft. (0-221 m)
Primary rock type limestone
Secondary rock type siltstone
Other rock types
Lithologic constituents
Major
Sedimentary > Carbonate > Limestone (Reef)limestones - locally reefy
Minor
Sedimentary > Clastic > SiltstoneSte. Therese Siltstone at base
Map references
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.
Unit references
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 Clinton - Essex - Orange - Saint Lawrence - Washington