Upper part of Rangeley Formation

Rusty-weathering, pelitic schist, metasandstone, and local coarse-grained metasandstone lentils; calc-silicate pods common; minor coticule. Probably equivalent to member C of Rangeley Formation of Maine.
State New Hampshire
Name Upper part of Rangeley Formation
Geologic age Lower Silurian (Llandoverian)
Lithologic constituents
Major
Metamorphic > Metasedimentary > Metaclastic > Metasandstonemetasandstone, and local coarse-grained metasandstone lentils
Metamorphic > Schist > Pelitic-schist
Minor
Metamorphic > Metasedimentary > Calc-silicate-rockcalc-silicate pods common; minor coticule
Comments Part of the Central Maine Composite Terrane (Central Maine Trough) - Variably metamorphosed sedimentary and volcanic rocks of greenschist to granulite facies, locally migmatized. Area includes structural belts between the Monroe fault on the west and the Campbell Hill fault on the east; that is, the Bronson Hill anticlinorium, Piedmont allochthon, Kearsarge-central Maine synclinorium, central New Hampshire anticlinorium, and Rochester-Lebanon (Maine) antiformal synclinorium. Granite sill, Gilmanton quadrangle (point within formation): 372+/-? U/Pb, monazite per NH030. Granite pegmatite, Suncook quadrangle (point within formation) 375+/-? U/Pb per NH030.
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

Eusden, J.D., Jr., and Barreiro, Barbara, 1988, The timing of peak high-grade metamorphism in central-eastern New England: Maritime Sediments and Atlantic Geology, v. 24, p. 241-255.

NGMDB product
Counties Belknap - Carroll - Cheshire - Grafton - Hillsborough - Merrimack - Strafford - Sullivan