Stamford Granite - rapakivi granite (VTZCcbs;0)

Stamford Granite - rapakivi granite

Light-gray to medium-gray, very coarse grained biotite-plagioclase-microcline rapakivi granite; contains large megacrysts of microcline perthite having rims of plagioclase that contain inclusions of biotite and garnet. Unit includes lesser irregular dikes and segregations of hornblende-biotite ferrodiorite and ferromonzonite. U-Pb zircon upper-intercept age of 962±1 Ma, no. 20 (revised from Karabinos and Aleinikoff, 1990). Cardinal Brook Intrusive Suite (965±4 Ma to 945±7 Ma). Rocks of the Green Mountain and Lincoln Mountain massifs and eastern domes.

State	Vermont
Name	Stamford Granite - rapakivi granite
Geologic age	Neoproterozoic
Lithologic constituents	Major Igneous > Plutonic > Granitic > GraniteLight-gray to medium-gray, very coarse grained biotite-plagioclase-microcline rapakivi granite; contains large megacrysts of microcline perthite having rims of plagioclase that contain inclusions of biotite and garnet. Minor Igneous > Plutonic > Dioritic > Diorite (Dike or sill)Unit includes lesser irregular dikes and segregations of hornblende-biotite ferrodiorite and ferromonzonite. Igneous > Plutonic > Syenitic > Monzonite (Dike or sill)Unit includes lesser irregular dikes and segregations of hornblende-biotite ferrodiorite and ferromonzonite.
Comments	Original unit label is Y3Ccbs, but age listed as Neoproterozoic. Changed label to ZCcbs.
References	Ratcliffe, N.M., Stanley, R.S., Gale., M.H., Thompson, P.J., and Walsh, G.J., 2011, Bedrock geologic map of Vermont: U.S. Geological Survey Scientific Investigations Map 3184, 3 sheets, scale 1:100,000. https://pubs.er.usgs.gov/publication/sim3184
NGMDB product	NGMDB product page for 96860
Counties	Bennington

Stamford Granite - rapakivi granite

Ratcliffe, N.M., Stanley, R.S., Gale., M.H., Thompson, P.J., and Walsh, G.J., 2011, Bedrock geologic map of Vermont: U.S. Geological Survey Scientific Investigations Map 3184, 3 sheets, scale 1:100,000.