Mink Narrows copper deposit, Lake Athapapuskow, Manitoba

Abstract

The Mink Narrows copper deposit of Copper Reef Mines (1973) Ltd., is one of several massive sulphide deposits in the Flin Flon region, northern Manitoba. It outcrops on a small reef off the north shore of Lake Athapapsukow, 14 miles southeast of Flin Flon. The vertical sheet-like deposit occurs in the basic metavolcanic rocks of the Amisk Group and is approximately parallel to the contact of a nearby grandodioritic intrusion. The host rocks have been recrystallized and later affected by minor retrograde metamorphism. Adjacent to the intrusion, the metavolcanics have been fractured. An alteration zone of sericite, chlorite, carbonate and quartz is associated with the deposit. Pyrite, pyrrhotite, chalcopyrite and sphalerite, are the major metallic minerals within the deposit and are present as both massive and disseminated sulphides. Consistent zonation of copper and zinc is not present within the deposit, however zoning occurs in several of the hole intersections. Metamorphism of the sulphides is indicated by their recrystallization, replacement and cataclastic features. Two main genetic possibilities exist for the deposit, either emplacement by hydrothermal fluids from the granodiorite intrusion, or by activities related to the volcanism.