Calc-silicate alteration in the Hemlo gold deposit, Ontario: mineral assemblages, P-T-X constraints and significance

A late calc-silicate alteration characterizes the Archean Hemlo gold deposit in Ontario, Canada. Calc-silicate minerals, including epidote-clinozoisite, remolite-actinolite, titanite, prehnite, pumpellyite, allanite, grossular garnet, antimonian vesuvianite, and armenite, oc-cur as mono- or bi-mineralic veins or aggregates but are volumetrically minor in the main orebody (Golden Giant mine). Aggregates of various combinations of tremolite-actinolite, clinopyroxene, phlogopite, talc, chlorite, calcite, dolomite, microcline, tourmaline, and quartz are abundant in the diffuse westward extension (C zone of the Williams mine an