Biotite granite

Contains minor muscovite. Makes up Cambridge Black pluton.
State New Hampshire
Name Biotite granite
Geologic age Middle Ordovician
Lithologic constituents
Major
Igneous > Plutonic > Granitic > Granite (Pluton)Biotite granite - Contains minor muscovite. Makes up Cambridge Black pluton.
Comments Rocks of the Chickwolnepy intrusions in northern New Hampshire (Middle Ordovician). Cambridge Black pluton of Chickwolnepy intrusions = 468+/-7 U/Pb per Aleinikoff, J.N., oral communication, Feb. 1994.
References
NGMDB product
Counties Coos