Braintree Intrusive Complex - metadiorite to metamonzodiorite

Medium-gray-weathering, porphyritic dikes and sills of fine- to medium-grained hornblende-biotite diorite and quartz diorite, and coarse-grained quartz monzodiorite. Has a U-Pb zircon TIMs age of 419±0.39 Ma, no. 36 (Black and others, 2004). Narrow zone of garnet-biotite-plagioclase-cordierite hornfels in the Moretown Formation postdates dominant foliation (Taconian) in host rocks. Part of the Lake Memphremagog Intrusive Suite (425±3 Ma to 418.5±2 Ma).
State Vermont
Name Braintree Intrusive Complex - metadiorite to metamonzodiorite
Geologic age Late Silurian
Lithologic constituents
Major
Igneous > Plutonic > Dioritic > Quartz-diorite (Dike or sill)Medium-gray-weathering, porphyritic dikes and sills of fine- to medium-grained hornblende-biotite diorite and quartz diorite, and coarse-grained quartz monzodiorite.
Igneous > Plutonic > Dioritic > Quartz-monzodiorite (Dike or sill)Medium-gray-weathering, porphyritic dikes and sills of fine- to medium-grained hornblende-biotite diorite and quartz diorite, and coarse-grained quartz monzodiorite.
Igneous > Plutonic > Dioritic > Diorite (Dike or sill)Medium-gray-weathering, porphyritic dikes and sills of fine- to medium-grained hornblende-biotite diorite and quartz diorite, and coarse-grained quartz monzodiorite.
References
NGMDB product
Counties Orange - Windsor