Manganese ore in New Zealand

Abstract

Abstract Manganese ore in New Zealand can be divided into: (a) manganese gangue in auriferous quartz lodes; (b) manganese pockets or masses associated with contemporaneous “Red Rocks” in Permian–Cretaceous sediments; and (c) manganese pockets or lenses associated with metamorphosed “Red Rocks” in regionally metamorphosed schists. All the manganese mined has come from Permian–Jurassic rocks in (b), the characteristic features of the deposits being their patchiness and their close association with “Red Rocks” that are intercalated as scattered subordinate masses in the dominant greywackes and argillites. The “Red Rocks” consist of spilitic lavas, jaspers, cherts, volcanic argillites and carbonate, and the manganese is considered to have been precipitated during the submarine volcanism. The deposits do not lend themselves to large scale mining but selectively worked by small parties, as is done in the Otau region, they can contribute to New Zealand's mineral wealth and could supplement imports if ever there ...