Madrid Formation (NHSm;0)

Madrid Formation

Massive to weakly foliated, purple biotite-feldspar granofels, layered calc-silicate, and dark pelitic-sulfidic schist containing calc-silicate pods in upper member; an eastern facies equivalent to the upper part of the Fitch Formation. Locally mapped as the Warner Formation of Nielson (1981) in southern New Hampshire.

State	New Hampshire
Name	Madrid Formation
Geologic age	Upper Silurian?
Lithologic constituents	Major Metamorphic > Granoblastic > Granofelsmassive to weakly foliated, purple biotite-feldspar granofels Metamorphic > Metasedimentary > Calc-silicate-rocklayered calc-silicate, dark pelitic-sulfidic schist containing calc-silicate pods in upper member Metamorphic > Schist > Pelitic-schistdark pelitic-sulfidic schist
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.
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 Nielson, D.L., 1981, The bedrock geology of the Hillsboro quadrangle, New Hampshire: New Hampshire Department of Resources and Economic Developement Bulletin 8, 76 p.
NGMDB product	NGMDB product page for 37338
Counties	Carroll - Coos - Grafton - Hillsborough - Merrimack - Strafford

Madrid Formation

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.

Nielson, D.L., 1981, The bedrock geology of the Hillsboro quadrangle, New Hampshire: New Hampshire Department of Resources and Economic Developement Bulletin 8, 76 p.