Biotite granite

Pink, moderately to weakly foliated.
State New Hampshire
Name Biotite granite
Geologic age Late Ordovician
Lithologic constituents
Major
Igneous > Plutonic > Granitic > Granite (Pluton)Biotite granite - Pink, moderately to weakly foliated.
Comments Part of the Oliverian Plutonic Suite (Late Ordovician) - Pink, weakly to moderately foliated, locally porphyritic biotite granitoids found in mantled gneiss domes. Mafic varieties contain hornblends. Variably metamorphosed up to amphibolite facies. Oliverian Plutonic Suite: Jefferson dome intrusive rocks = 441+/-5 Rb/Sr per NH021. 444+/-8 U/Pb per NH020. 456+/-3 U/Pb per NH015. 454+/-5 U/Pb per J.N. Aleinikoff, oral commun., Feb. 1994. Sugar Hill dome intrusive rocks = 444+/-8 U/Pb per NH020. Owls Head dome intrusive rocks = 444+/-8 per NH020. Lebanon intrusive rocks = 431+/-30 Rb/Sr per NH027. Mascoma Granite = 450+/-25 U/Pb and 431+/-30 Rb/Sr per NH027. Keene and Surry dome intrusive rocks = 444+/-8 U/Pb per NH020.
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

Aleinikoff, J.N., and Moench, R.H., 1987, U-Pb geochronology and Pb isotopic sytematics of plutonic rocks in northern New Hampshire; ensimatic vs. ensialic sources [abs.]: Geological Society of America Abstracts with Programs, v. 19, p. 1-2.

Zartman, R.E., and Leo, G.W., 1985, New radiometric ages on gneisses of the Oliverian domes in New Hampshire and Massachusetts: American Journal of Science, v. 285, p. 267-280.

Foland, K.A., and Loiselle, M.C., 1981, Oliverian syenites of the Pliny region, New Hampshire: Geological Society of America Bulletin, v. 92, pt. 1, p. 179-188.

Naylor, R.S., 1969, Age and origin of the Oliverian domes, central-western New Hampshire: Geological Society of America Bulletin, v. 80, p. 405-427.

NGMDB product
Counties Cheshire - Coos - Grafton