the moss au deposit is an orogenic-style gold deposit hosted in felsic to intermediate rocks of the western shebandowan greenstone belt, close to the terrane boundary between the wawa-abitibi terrane and the quetico metasedimentary basin, ~120 km west of thunder bay. the deposit has an inferred mineral estimate of 140.07 mt of ore averaging 1.09 g/t au, which yields 4.91 moz (goldshore, 2024). the majority of the gold is hosted within diorite and dacite and is localized by shear zones and an array of quartz-carbonate-pyrite veins. the central-felsic metavolcanic belt of the shebandowan greenstone belt comprises felsic to intermediate units surrounded by late granitic intrusions, such as the burchell lake and moss lake stocks. this study focused on characterizing the alteration and mineralization at the moss deposit and investigating any correlation between alteration and gold mineralization. a combination of petrography, geochronology, geochemistry, and mineral chemistry was used to achieve the objectives of this study. alteration occurs in different styles and intensities but generally comprises albite, biotite, sericite, chlorite, carbonate, and epidote alteration. sulfide minerals are dominated by pyrite with minor chalcopyrite, sphalerite and molybdenite. sulfide abundance is commonly 2 – 10% of the samples but can be up to 15% within sulfide-rich veins. disseminated and vein-hosted pyrite are the two main textures in which pyrite occurs within the host rocks. a total of 12 vein types were observed, with quartz and carbonate being the most dominant veins occurring together in five of the vein types. using the observed textural and crosscutting relationships of the alteration, sulfides, and veins, a paragenetic sequence was developed, highlighting the secondary processes associated with the formation of the moss lake deposit. deformation textures were observed in early and late alteration phases, suggesting a long deformation history that was broadly coeval with mineralization. quartz-carbonate-pyrite ± sericite ± chlorite ± epidote veins are host to most of the observed gold occurrences, and are common within or in proximity to shear zones. gold was rarely associated with disseminated pyrite away from veins. [...]