Mount Holly Complex, quartzite and schist (VTpCAsq;0)

Mount Holly Complex, quartzite and schist - Quartzite, locally in massive beds as much as 30 ft thick, micaceous quartzite, and quartz-mica schist that commonly contains garnet or pseudomorphs (largely chlorite) after garnet; schists are locally rusty weathered and contain conspicuous flakes of graphite; also includes amphibolite and minor hornblende gneiss, biotite gneiss, and pegmatite.

State	Vermont
Name	Mount Holly Complex, quartzite and schist
Geologic age	Precambrian
Original map label	pCsq
Comments	Part of Green Mountains Cores of abraded zircon obtained from College Hill Granite Gneiss of Mount Holly Complex have a U-Pb upper intercept age of 1245 +/-14 Ma, interpreted as crystallization age for that granite (Aleinikoff and others, 1990) per VT016.
Primary rock type	quartzite
Secondary rock type	mica schist
Other rock types	amphibolite; mafic gneiss; biotite gneiss; pegmatite
Lithologic constituents	Major Metamorphic > Schistquartz-mica schist that commonly contains garnet or pseudomorphs (largely chlorite) after garnet; schists are locally rusty weathered and contain conspicuous flakes of graphite Metamorphic > Metasedimentary > Metaclastic > QuartziteQuartzite, locally in massive beds as much as 30 ft thick, micaceous quartzite, Minor Metamorphic > Gneissminor hornblende gneiss, biotite gneiss Incidental Igneous > Plutonic > Granitic > Leucocratic-granitic > Pegmatite Metamorphic > Amphibolite
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. Ratcliffe, N.M., in press, Bedrock geologic map of the Jamaica quadrangle and portions of the Townshend quadrangle, Windham County, Vermont: U.S. Geological Survey Miscellaneous Investigations Series Map, I-__, 1 sheet, scale 1:24,000. [http://pubs.er.usgs.gov/publication/i2453]
Geographic coverage	Addison - Bennington - Rutland - Windham - Windsor