Ayer Granodiorite

Gneissic granite to tonalite, locally coarsely porphyritic and muscovitic, southeastern New Hampshire.
State New Hampshire
Name Ayer Granodiorite
Geologic age Early Silurian
Lithologic constituents
Major
Igneous > Plutonic > Granitic > GranodioriteGneissic granite to tonalite, locally coarsely porphyritic and muscovitic.
Minor
Igneous > Plutonic > Granitic > TonaliteGneissic granite to tonalite, locally coarsely porphyritic and muscovitic.
Igneous > Plutonic > Granitic > GraniteGneissic granite to tonalite, locally coarsely porphyritic and muscovitic.
Comments Ayer Granodiorite = 433+/-5 U/Pb per NH043.
References

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.

https://ngmdb.usgs.gov/Prodesc/proddesc_37338.htm

Zartman, R.E., and Naylor, R.S., 1984, Structural implications of some radiometric ages of igneous rocks in southeasten New england: Geological Society of America Bulletin, v. 95, p. 522-539.

NGMDB product
Counties Hillsborough - Rockingham