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National Geologic Map Database

Geologic Unit: Chazy

Usage:

Chazy Group (NY*,VT*)

[Use of Chazy as a lithostratigraphic term (Chazy Group) should be discontinued. It is more widely used as a North American provincial chronostratigraphic term (Chazyan Stage).]


Subunits:

GROUP STATUS (alphabetical): Crown Point Limestone (NY*,VT*), Day Point Formation (NY*,VT*) or Day Point Limestone (NY*,VT*), Valcour Formation (NY*,VT*) or Valcour Limestone (NY*,VT*).


Geologic age:

Middle to Late Ordovician (Whiterockian; Chazyan)*


Type section, locality, area and/or origin of name:

Named from exposures at Chazy, Clinton Co., eastern NY (Emmons, 1842).


AAPG geologic province:

Adirondack uplift*
Appalachian basin*
New England province*


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates published by U.S. Geological Survey authors.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).