Monadnock Mountain pluton - essexite (VTJme;0)

Monadnock Mountain pluton - essexite

Pyroxene-biotite-hornblende andesine gabbroic rock grading into quartz syenite. Monadnock Mountain pluton: Composite stock of quartz syenite, syenite granite, and essexite. K-Ar age of 175±4 Ma (Foland and Faul, 1977). Part of the White Mountain Igneous Suite.

State	Vermont
Name	Monadnock Mountain pluton - essexite
Geologic age	Middle Jurassic
Lithologic constituents	Major Igneous > Plutonic > Syenitic > Quartz-syenite (Pluton)Pyroxene-biotite-hornblende andesine gabbroic rock grading into quartz syenite. Igneous > Plutonic > Gabbroic (Pluton)Pyroxene-biotite-hornblende andesine gabbroic rock grading into quartz syenite. Essexite.
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	Essex

Monadnock Mountain pluton - essexite

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.