Nassau Formation

Gray to dark-greenish-gray, siliceous phyllite with abundant beds of quartzite, olive-gray metasiltstone and subgraywacke (includes Bomoseen Graywacke Member and Zion Hill quartzite Member).
State Massachusetts
Name Nassau Formation
Geologic age Lower Cambrian and Proterozoic Z
Lithologic constituents
Major
Metamorphic > Metasedimentary > Metaclastic > PhylliteGray to dark-greenish-gray, siliceous phyllite.
Minor
Metamorphic > Metasedimentary > Metaclastic > Quartzite
Metamorphic > Metasedimentary > Metaclastic > Metasiltstoneolive-gray metasiltstone and subgraywacke
Metamorphic > Metasedimentary > Metaclastic > Metasandstone > Metagraywackeolive-gray metasiltstone and subgraywacke
Comments Part of Taconic-Berkshire Zone (Ordovician and Older Rocks); in the Taconic Allochthon
References
NGMDB product
Counties Berkshire