Porphyritic phase of hornblende-biotite tonalite

Porphyritic phase of hornblende-biotite tonalite.
State New Hampshire
Name Porphyritic phase of hornblende-biotite tonalite
Geologic age Middle Ordovician
Lithologic constituents
Igneous > Plutonic > Granitic > Tonaliteporphyritic phase of hornblende-biotite tonalite.
Comments Rocks of the Chickwolnepy intrusions in northern New Hampshire (Middle Ordovician). Chickwolnepy Complex of Moench and others (1982) = 467+/-4 U/Pb per NH018.

Lyons, J.B., Bothner, W.A., Moench, R.H., and Thompson, J.B., Jr., 1997, Bedrock Geologic Map of New Hampshire: Reston, VA, U.S. Geological Survey Special Map, 2 sheets, scale 1:250,000.


Aleinikoff, J.N., and Moench, R.H., 1992, U-Pb zircon ages of the Ordovician Ammonoosuc Volcanics and related plutons near Littleton and Milan, New Hampshire [abs.]: Geological Society of America Abstracts with Programs, v. 24, p. 2.

NGMDB product
Counties Coos