Cobble Mountain Formation

Red rusty-weathering schist containing thin beds of white quartz-plagioclase granofels and vitreous quartzite. Local amphibolite and thin anthophyllite amphibolite.
State Massachusetts
Name Cobble Mountain Formation
Geologic age Middle Ordovician
Lithologic constituents
Major
Metamorphic > Schist
Minor
Metamorphic > Metasedimentary > Metaclastic > Quartzitevitreous quartzite
Metamorphic > AmphiboliteLocal amphibolite and thin anthophyllite amphibolite.
Metamorphic > Granoblastic > Granofelsquartz-plagioclase granofels
Comments Part of Rowe-Hawley Zone (Ordovician and Older Rocks)
References
NGMDB product
Counties Hampden