Gabbroic or noritic metanorthosite

Dark mineral content in excess of 10 percent (part of unit Ya).
State New York
Name Gabbroic or noritic metanorthosite
Geologic age Middle Proterozoic
Lithologic constituents
Metamorphic > Metaigneous > Metaintrusive > MetaanorthositeGabbroic or noritic metanorthosite
Comments Printed map does not contain a unit named 'ao'; only a unit named 'a' and mentions that 'overprint signifies dark mineral content in excess of 10 percent (mainly gabbroic or noritic metanorthosite)'. Overprint means that a different pattern is used over the color of unit 'a'. The digital version of the map has separated this unit out into a new unit and called it 'ao', so I have included it here.

Fisher, D.W., Isachsen, Y.W., and Rickard, L.V., 1970, Geologic Map of New York State, consisting of 5 sheets: Niagara, Finger Lakes, Hudson-Mohawk, Adirondack, and Lower Hudson, New York State Museum and Science Service, Map and Chart Series No. 15, scale 1:250,000.

NGMDB product
Counties Herkimer