Smalls Falls Formation, Felsic metavolcanic member

Smalls Falls Formation, Felsic metavolcanic member.
State New Hampshire
Name Smalls Falls Formation, Felsic metavolcanic member
Geologic age Upper to Middle Silurian (Ludlovian and Wenlockian)
Lithologic constituents
Metamorphic > Metaigneous > Metavolcanicfelsic metavolcanic
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. Felsic metatuff of the Rangeley Formation (shown on this map as the Smalls Falls Formation) = 432+/-8 U/Pb per NH015.

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.

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.

NGMDB product
Counties Coos