Silicate, sulfide, and platinum - group petrology and mineralogy of the Kawene Intrusion, Quetico subprovince

Abstract

The Kawene Intrusion is an ultramafic, layered, metamorphosed Cu- Ni- PGE- bearing intrusion located 29 km east of Atikokan within the Quetico Subprovince of northwestern Ontario. The Kawene Intrusion is emplaced primarily in metasedimentary turbiditic wacke. The intrusion is composed of hornblende wehrlite in the center, with hornblende clinopyroxenite, clinopyroxene hornblendite, and hornblende melagabbro at the margin. The intrusion has been metamorphosed to upper greenschist - to - lower amphibolite metamorphic grade. The mineralized area is composed of alternating layers of hornblende clinopyroxenite and clinopyroxene hornblendite intruded by tonalite veins, and sulfide veinlets. The sulfide veinlets and the disseminated sulfides consist mainly of chalcopyrite, pyrrhotite, and pentlandite. The other sulfides found in these ultramafic rocks in decreasing order of abundance are ; galena, violarite, and sphalerite. The Platinum - Group Minerals (PGM) are spatially associated with the sulfides.