Rhyolite and fine-grained granite

Includes some ignimbritic caldera-fill and minor intrusive rocks (part of Ossipee Mountain Complex of Kingsley, 1931); also some aphanitic gray, black, or tan quartz-feldspar porphyry.
State New Hampshire
Name Rhyolite and fine-grained granite
Geologic age Cretaceous
Lithologic constituents
Major
Igneous > Plutonic > Granitic > Granite
Igneous > Volcanic > Felsic-volcanic > Rhyolite
Minor
Igneous > Plutonicminor intrusive rocks; also some aphanitic gray, black, or tan quartz-feldspar porphyry.
Igneous > Volcanic (Pyroclastic)includes some ignimbritic caldera-fill and minor intrusive rocks
Comments Part of the New England-Quebec igneous province of McHone and Butler (1984). Overall, part of the White Mountain Plutonic-Volcanic Suite - Includes Cretaceous alkalic syenite to granitic to gabbroic plutons, minor volcanic rocks, and lamprophyre dikes of the New England-Quebec igneous province of McHone and Butler (1984); also includes Jurassic granite and syenite and less abundant quartz syenite, diorite, gabbro, nepheline syenite, and volcanic rocks of the White Mountain igneous province of McHone and Butler (1984).
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

McHone, J.G., and Butler, J.R., 1984, Mesozoic igneous provinces of New England and the opening of the North Atlantic Ocean: Geological Society of America Bulletin, v. 95, p. 757-765.

Kingsley, Louise, 1931, Cauldron subsidence of the Ossipee Mountains: American Journal of Science, v. 12, p. 134-167.

NGMDB product
Counties Belknap - Carroll - Strafford