- Usage in publication:
-
- Oswegatchie series
- Modifications:
-
- Named
- Dominant lithology:
-
- Limestone
- Gneiss
- AAPG geologic province:
-
- Adirondack uplift
Summary:
Named Oswegatchie series for the Oswegatchie River that flows through these rocks for many miles in northern NY. Unit is white to gray crystalline limestone, weathering nearly black, and interbedded gneiss of sedimentary origin but extremely metamorphosed. The Oswegatchie unconformably underlies Potsdam sandstone; the base of the unit is in doubt, because of uncertainty whether all gneiss of region belongs with the limestone and is a part of the Oswegatchie series, or whether part of gneiss is older and unconformably beneath the Oswegatchie. Similarity of rocks suggests equivalency to Grenville series of Canada, but local name seems desirable. It is considered of Precambrian age.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Oswegatchie Group
- Modifications:
-
- Revised
- AAPG geologic province:
-
- Adirondack uplift
Summary:
Poplar Hill Gneiss (adopted by author as Popple Hill) removed from Oswegatchie Group as Poplar Hill has basaltic origin while Oswegatchie is group of metasediments. Author regards Poplar Hill and Hyde School Gneisses as belonging to sequence of alternating platformal sedimentary and volcanic rocks. Author objects to group status assigned by Wiener and others (1984) to rocks in the northwest Adirondacks.
Source: GNU records (USGS DDS-6; Reston GNULEX).
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 conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).