Metabasalt

Sequence of conformably layered volcanic rocks of fine-grained to aphanitic, greenish-gray, retrogressively metamorphosed greenstone, greenschist, and basalt. Greenschist contains clots and lenses of blue quartz and abundant sulfide. Unit does not crop out and is known only from subsurface borings and artificial exposures. Interpreted to be Late Proterozoic by Volkert and Drake (1993) on the basis of geochemical similarity to Late Proterozoic metadiabase dikes in New Jersey Highlands.
State New Jersey
Name Metabasalt
Geologic age Late Proterozoic
Lithologic constituents
Major
Metamorphic > Metaigneous > Metavolcanic > Metabasaltfine-grained to aphanitic, greenish-gray, retrogressively metamorphosed basalt
Metamorphic > Schist (Greenschist)fine-grained to aphanitic, greenish-gray, retrogressively metamorphosed greenschist; greenschist contains clots and lenses of blue quartz and abundant sulfide
Metamorphic > Metaigneous > Greenstonefine-grained to aphanitic, greenish-gray, retrogressively metamorphosed greenstone
Comments Rocks of the Trenton prong
References
NGMDB product
Counties Mercer