Nickeliferous Pyrrhotite Deposits, Knox County, Southeastern Maine
Published:January 01, 1976
Nickeliferous ores (pyrrhotite, pentlandite, and chalcopyrite) in the Harriman peridotite and Warren gabbro-diorite of Knox County, southeastern Maine, occur as lenticular bodies in the Ordovician Penobscot Formation. The ore bodies were emplaced in Late Ordovician time, most likely synchronously with the Taconic orogeny; they were later modified by Acadian dynamothermal and Permian thermal metamorphism.
The Harriman body is a feldspathic lherzolite peridotite with limited serpentinization in the central zone. The amount of serpentine, amphiboles, talc, and carbonate minerals increases markedly away from the central zone, thus defining a crude zoning pattern. Sulfides occur interstitially or, less commonly, as thin massive...