Biotite-quartz-plagioclase gneiss

Commonly very low in biotite content, with interbedded feldspathic and biotitic quartzite and amphibolite; sillimanite and garnet common, graphite sporadic.
State New York
Name Biotite-quartz-plagioclase gneiss
Geologic age Middle Proterozoic
Lithologic constituents
Metamorphic > GneissBiotite-quartz-plagioclase gneiss - commonly very low in biotite content
Metamorphic > Metasedimentary > Metaclastic > Quartzitefeldspathic and biotitic quartzite
Metamorphic > Amphibolite

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 Fulton - Hamilton - Herkimer - Saratoga