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
NGMDB product
Counties Bennington