Collinsville Formation

Brown to rusty-brown schist containing coticule and locally massive amphibolite at base.
State Massachusetts
Name Collinsville Formation
Geologic age Middle Ordovician or older
Lithologic constituents
Major
Metamorphic > Schistbrown to rusty-brown schist containing coticule
Metamorphic > Amphibolite
Comments Part of Bronson Hill Zone (Ordovician and Older Rocks)
References
NGMDB product
Counties Hampden