Normanskill Formation

Shale, argillite, siltstone.
State New York
Name Normanskill Formation
Geologic age Middle Ordovician
Lithologic constituents
Major
Sedimentary > Clastic > Mudstone > Shale
Minor
Sedimentary > Clastic > Siltstone
Metamorphic > Metasedimentary > Metaclastic > Argillite
Comments part of Trenton Group and Metamorphic Equivalents up to 8000 ft. (2400 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 Dutchess - Orange - Ulster