Mount Holly Complex, calcite and dolomite marbles (VTpCAm;0)

State	Vermont
Name	Mount Holly Complex, calcite and dolomite marbles
Geologic age	Precambrian
Original map label	pCm
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	marble
Secondary rock type	granulite
Other rock types	metamorphic rock
Lithologic constituents	Major Metamorphic > Granuliteinterbedded with medium- to coarse-grained calc-silicate granulite Metamorphic > Metasedimentary > Metacarbonate > Marblecalcite and dolomite marbles - locally coarse grained; commonly contain phlogopite, actinolite, and diopside Incidental Metamorphicincludes minor amounts of other types of Precambrian rock
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	Bennington - Rutland - Windham - Windsor