Granite porphyry (NHJ1hx;0)

State	New Hampshire
Name	Granite porphyry
Geologic age	Early Jurassic
Original map label	J1hx
Comments	Part of the White Mountain 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). White Mountain Plutonic-Volcanic suite, Mount Lafayette Granite Porphyry = 195+/-6 K/Ar per NH023.
Primary rock type	granite
Secondary rock type
Other rock types
Lithologic constituents	Major Igneous > Plutonic > Granitic (Pluton)granite containing phenocrysts of smoky quartz and microperthite; alkalic amphibole, hornblende, and hedenbergite or fayalite may be present
Map references	Bennett, D. S, , Wittkop, C.A., and Dicken, C.L., 2006 , Bedrock Geologic Map of New Hampshire - A Digital Representation of the Lyons and others 1997 map and ancillary files: U.S. Geological Survey Data Series 215, scale 1:250,000, CD-ROM. [http://pubs.er.usgs.gov/publication/ds215]
Unit 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, 1:250,000, 2 sheets. Billings, M.P., 1955, Geologic map of New Hampshire: Washington, D.C., U.S. Geological Survey, scale 1:250,000. 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. Eby, G.N., Krueger, H.M., and Creasy, J.W., 1992, Geology, geochronology, and geochemistry of the White Mountain batholith, New Hampshire, in Puffer, J.H., and Ragland, P.C., eds., Eastern North American Mesozoic magmatism: Geological Society of America Special Paper 268, p. 379-397.
Geographic coverage	Carroll - Coos - Grafton