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Conway Granite

Conway Granite - Typically pink, coarse-grained mesoperthitic biotite (amphibole-free) granite; locally fine-grained or porphyritic.
StateNew Hampshire
NameConway Granite
Geologic ageMiddle - Late? Jurassic
Original map labelJc1b
CommentsPart 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). Middle - Late? Jurassic White Mountain Plutonic-Volcanic Suite: Gore Mountain granitic intrusive rocks = 169+/-3 K/Ar per NH013. Percy pluton = 166+/-4 K/Ar per NH013. Pliny Range intrusive rocks = 182+/-4 and 189+/-5 K/Ar per NH013; also 183+/-2 Ar/Ar per NH019. Cannon Mountain pluton = 184+/-4 K/Ar per NH022 and 194+/-4 K/Ar per NH013. Conway Granite = 183+/-5, 182+/-4, 180+/-4, 178+/-4, 171+/-4, and 155+/-4 K/Ar per NH023. Mad River pluton = 178+/-5 K/Ar, 158+/-4 Rb/Sr, biotite, per NH022. Belknap intrusive rocks = 159+/-3 K/Ar per NH022. 161+/-5 Rb/Sr and 158+/-3 K/Ar, biotite, per NH013. 169.3+/-1.7 Rb/Sr per NH033.
Primary rock typegranite
Secondary rock type
Other rock types
Lithologic constituents
Major
Igneous > Plutonic > Granitic > Granite (Pluton)typically pink, coarse-grained mesoperthitic biotite (amphibole-free) granite; locally fine-grained or porphyritic
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.
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.
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.
Foland, K.A., and Faul, Henry, 1977, Ages of the White Mountain intrusives, New Hampshire, Vermont and Maine, U.S.A.: American Journal of Science, v. 277, p. 888-904.
Randall, K.A., and Foland, K.A., 1986, Age and time of emplacement of the Pliny Range complex, northern New Hampshire: Geological Society of America Bulletin, v. 97, p. 595-602.
Foland, K.A., Quinn, A.W., and Giletti, B.J., 1971, K-Ar and Rb-Sr Jurassic and Cretaceous ages for intrusives of the White Mountain magma series, northern New England: American Journal of Science, v. 270, p. 321-330.
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.
Loiselle, M.C., and Hart, S.R., 1978, Sr isotropic systematics of the Belknap Mtns. complex. New Hampshire [abs.]: Geological Society of America Abstracts with Programs, v. 10, p. 73.
Geographic coverageBelknap - Carroll - Coos - Grafton

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