METAMORPHIC P-T PATHS FROM THE EASTERN FLIN-FLON BELT AND KISSEYNEW DOMAIN, SNOW LAKE, MANITOBA

Alteration zones around a volcanogenic Cu-Zn-Au massive sulfide deposi t in the Paleoproterozoic Trans-Hudson Orogen at Photo Lake, near Snow Lake, Manitoba, and in the Kisseynew Domain experienced multiple stag es of metamorphism and metasomatic alteration during the deformation e vents. In the Snow Lake area, F-1 produced a chlorite-grade schistosit y. During F-2, pressure increased by 1-2 kbar, and temperature increas ed by 10-50 degrees C, up to approximately 5 kbar and 550 degrees C, a t which time most of the F-2 strain occurred, destroying most evidence of S-1. This was followed by a continued temperature increase of 10-2 0 degrees C. Peak metamorphic, syn-F-2 assemblages in the altered volc anic rocks include staurolite + garnet + biotite, and kyanite + chlori te. F-3 produced a crenulation of S-2, along with minor chloritization at 400-450 degrees C. In alteration zones in the Kisseynew Domain, S- 1 is obscure, but garnet grew prior to, during, and after the developm ent of the S-2 fabric, as is the case at Snow Lake. Likewise, metamorp hic conditions during F-2 were similar to those at Snow Lake during F- 2. However, rocks in the Kisseynew Domain were heated another 100-150 degrees C after growth of the garnet, as shown by the assemblage silli manite + garnet + biotite and geothermometry. They also acquired a gne issic fabric at or near the thermal peak of metamorphism Garnet + cord ierite assemblages and geobarometry suggest that metamorphic pressures during the thermal peak were similar to those at garnet grade. The fi nal heating event occurred after F-2 deformation, and requires a sourc e of heat localized under the Kisseynew Domain. Likely scenarios inclu de emplacement of plutons in and under the Kisseynew Domain during F-2 .