Yonkers Gneiss

Biotite and/or hornblende-quartz-feldspar gneiss.
State New York
Name Yonkers Gneiss
Geologic age Middle Proterozoic
Lithologic constituents
Major
Metamorphic > Gneissbiotite and/or hornblende-quartz-feldspar gneiss
Comments Age change per USGS Lexicon website (ref. NY046) and reference NY010.
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.

Rankin, D.W. (editor), Chiarenzelli, J.R., Drake, A.A., Jr., Goldsmith, Richard, Hall, L.M., Hinze, W.J., Isachsen, Y.W., Lidiak, E.G., McLelland, James, Mosher, Sharon, Ratcliffe, N.M., Secor, D.T., Jr. and Whitney, P.R., 1993, Proterozoic rocks east and southeast of the Grenville Front, IN Reed, J.C., Jr., and others, eds., Precambrian; conterminous U.S.: Geological Society of America, The Geology of North America, The Decade of North American Geology (DNAG), v. C-2, p.335-461.

USGS Geologic Names lexicon found at: http://ngmdb.usgs.gov/Geolex/

https://ngmdb.usgs.gov/Geolex/search

NGMDB product
Counties Bronx - Westchester