Newfane tonalite

Light-gray to cream-weathering, massive to gneissic, hornblende-biotite and muscovite-biotite metatrondhjemite and metatonalite. Forms a thick, sill-like intrusive extending northward from South Newfane, where it intrudes metavolcanics (Ochv) of the Cram Hill Formation. U-Pb zircon SHRIMP age of 502±4 Ma, no. 22 (Aleinikoff and others, 2011). North River Igneous Suite (502±4 Ma to 471.4±3.7 Ma): collection of metatonalite, metatrondhjemite, and metabasalt occurring as intrusive dikes, sills, and small stocks, and possibly meta-andesite and metadacitic tuffs. Correlative with extrusive dacitic metavolcanic and meta-andesitic rocks of the Moretown and Cram Hill Formations. Coextensive in part with igneous rocks of the Hawley Formation of Massachusetts. Part of the Volcanic-arc intrusive and volcanic rocks of the North River Igneous Suite of the Rowe-Hawley zone. Rocks of the Early to Late Taconic Accreted Terrane of the Rowe-Hawley Zone. Eastern allochthonous sequence, oceanic and accretionary realm, ultramafic inclusions, volcanic-arc intrusives, and volcanic rocks.
State Vermont
Name Newfane tonalite
Geologic age Ordovician and Late Cambrian
Lithologic constituents
Major
Metamorphic > Metaigneous > Metaintrusive > MetatonaliteLight-gray to cream-weathering, massive to gneissic, hornblende-biotite and muscovite-biotite metatrondhjemite and metatonalite.
Metamorphic > Metaigneous > Metaintrusive > Metatonalite > MetatrondhjemiteLight-gray to cream-weathering, massive to gneissic, hornblende-biotite and muscovite-biotite metatrondhjemite and metatonalite.
Comments Original unit label is Onnt; but age is listed as Ordovician and Late Cambrian. Age confirmed as only Cambrian by U-Pb age in unit description. Changed unit label to CAnnt.
References
NGMDB product
Counties Windham - Windsor