Newport Intrusive Complex - diorite and trondhjemite

Metamorphosed diorite, trondhjemite, and diabase, consisting of massive to foliated, light-gray to grayish-green, chalky-weathering diorite with xenoliths of green phyllite and trondhjemite; and massive, tan-weathering, medium- to coarse-grained trondhjemite with xenoliths of diabase. Numerous crosscutting quartz-feldspar veinlets show in relief on the weathering surface. Unit intrudes Cram Hill Formation. U-Pb zircon SHRIMP age of 425±3 Ma, no. 39 (Aleinikoff and others, 2011). Part of the Lake Memphremagog Intrusive Suite (425±3 Ma to 418.5±2 Ma).
State Vermont
Name Newport Intrusive Complex - diorite and trondhjemite
Geologic age Late Silurian
Lithologic constituents
Major
Metamorphic > Metaigneous > Metaintrusive > Metatonalite > MetatrondhjemiteMetamorphosed diorite, trondhjemite, and diabase; xenoliths of green phyllite and trondhjemite; and massive, tan-weathering, medium- to coarse-grained trondhjemite with xenoliths of diabase.
Metamorphic > Metaigneous > Metaintrusive > MetadiabaseMetamorphosed diorite, trondhjemite, and diabase; massive, tan-weathering, medium- to coarse-grained trondhjemite with xenoliths of diabase.
Metamorphic > Metaigneous > Metaintrusive > MetadioriteMetamorphosed diorite, trondhjemite, and diabase, consisting of massive to foliated, light-gray to grayish-green, chalky-weathering diorite.
Minor
Metamorphic > Metasedimentary > Metaclastic > PhylliteXenoliths of green phyllite.
References
NGMDB product
Counties Orleans