Origin and emplacement of volcanogenic massive sulfide-hosting, Paleoproterozoic volcaniclastic and effusive rocks within the Flin Flon subsidence structure, Manitoba and Saskatchewan, Canada

The Flin Flon, Callinan, and 777 volcanogenic massive sulfide (VMS) deposits indicate a very complex succession of distinctive, heterolithic, effusive and volcaniclastic units.; The large volume, variable thickness, and restriction of volcaniclastic and effusive units in the Flin Flon formation to particular fault blocks, indicates they were emplaced into a large, fault controlled, volcanic-tectonic subsidence structure, or caldera, which has a minimum north-south strike extent of 5 km, and deepens to the north and east. Volcaniclastic rocks are dominantly basaltic to andesitic, they were emplaced as high-particle concentration mass flows, and represent primary, pyroclastic deposits or their redeposited, syneruptive equivalents derived from vents located within and, to a lesser extent, outside the subsidence structure. Renewed volcanism of voluminous basaltic and andesitic flows of the Hidden formation buried the Flin Flon formation and subsequently contained the VMS deposits. (Abstract shortened by UMI.)...