The geology and nickel-copper sulphide mineralisation in the Graham Valley, North-West Nelson

Abstract

In the Graham Valley, North-West Nelson, mafic and ultramafic rocks intruding lower Paleozoic sediments, are referred to the Riwaka Complex. At this locality the complex consists of two major rock types; the most extensive is pyroxenite with minor gabbro (Pokororo Pyroxenite) which encloses small discrete masses of peridotite (Graham Peridotite). Sulphides associated with the pyroxenite include pentlandite, pyrrhotite, and chalcopyrite; and chrome-spinel is associated with the peridotites.