Clough Formation (VTSc;1)

State	Vermont
Name	Clough Formation
Geologic age	Silurian
Original map label	Sc
Comments	Part of Eastern Vermont Secondary unit description from USGS Geologic Names lexicon (ref. VT030)4:40:01 PM Clough is considered the key stratigraphic unit in Bronson Hill anticlinorium because 1) it is dominated by distinctive, readily recognizable rock types, 2) where present, it is base of Silurian-Devonian sequence, resting with detectable unconformity on older rocks, and 3) it contains late Llandoverian fossils at several localities in western NH and adjacent VT, and at Bernardston, MA. Consists mostly of quartz-pebble conglomerate in which pebbles are typically deformed; other lithologies are quartz grit or white to pink, well-bedded quartzite. Locally contains some mica schist beds.
Primary rock type	conglomerate
Secondary rock type	quartzite
Other rock types	mica schist
Lithologic constituents	Major Sedimentary > Clastic > Conglomeratequartz-conglomerate Minor Metamorphic > Metasedimentary > Metaclastic > Quartzitequartzite; lenses of fossiliferous calcareous quartzite in upper part Incidental Metamorphic > Schist > Mica-schistmica schist
Map references	Nicholson, S.W., Dicken, C.L., Horton, J.D., Foose, M.P., Mueller, J.A.L., and Hon, Rudi, 2006, Preliminary integrated geologic map databases for the United States: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, Rhode Island, and Vermont: U.S. Geological Survey Open-File Report 2006-1272. [http://pubs.er.usgs.gov/publication/ofr20061272]
Unit references	Doll, C.G., Cady, W.M., Thompson, J.B., Jr., and Billings, M.P., 1961, Centennial Geologic Map of Vermont: Vermont Geological Survey, Miscellaneous Map MISCMAP-01, scale 1:250,000. USGS Geologic Names Lexicon (GEOLEX) [http://ngmdb.usgs.gov/Geolex/]
Geographic coverage	Essex - Windham - Windsor