Hornblende diorite gneiss

Coarse-grained hornblende-plagioclase (±quartz) dioritic gneiss and gabbroic gneiss mapped in the Londonderry area, where it is interpreted as metagabbro and has a U-Pb zircon SHRIMP age of 1,393±9 Ma, no. 1 (Aleinikoff and others, 2011). South Londonderry Igneous Suite (Middle and Early Mesoproterozoic) (1,393±9 Ma to 1,309±6 Ma). Mount Holly Complex intrusive rocks. Rocks of the Green Mountain and Lincoln Mountain massifs and eastern domes.
State Vermont
Name Hornblende diorite gneiss
Geologic age Early Mesoproterozoic
Lithologic constituents
Major
Metamorphic > Metasedimentary > ParagneissCoarse-grained hornblende-plagioclase (±quartz) dioritic gneiss and gabbroic gneiss.
Metamorphic > Metaigneous > Metaintrusive > MetagabbroGabbroic gneiss mapped in the Londonderry area, where it is interpreted as metagabbro.
References
NGMDB product
Counties Bennington - Windham - Windsor