Biotite-quartz-plagioclase gneiss

Light-greenish-gray to pinkish-gray, well-foliated and well-layered quartz-rich gneiss and more mafic biotite-hornblende-pyroxene-quartz-plagioclase gneiss irregularly distributed within unit. Unit may be in part older than the tonalitic gneiss (Y2bt). Paragneiss. Rocks of the Adirondacks in Vermont and in the Whitehall, N.Y., area.
State Vermont
Name Biotite-quartz-plagioclase gneiss
Geologic age Middle to Early Mesoproterozoic
Lithologic constituents
Major
Metamorphic > Metasedimentary > ParagneissLight-greenish-gray to pinkish-gray, well-foliated and well-layered quartz-rich gneiss and more mafic biotite-hornblende-pyroxene-quartz-plagioclase gneiss.
Comments Original label is Y2bpg, but age is Middle to Early Mesoproterozoic. Changed symbol to Y1Y2bpg.
References
NGMDB product
Counties Rutland