| Summary: | The Sugar gold prospect, located 20 km southeast of the Coffee gold deposits and 10 km northwest of the Casino Cu-Au-Mo deposit in the Yukon Territory, is hosted in the mid- Cretaceous Dawson Range batholith. Sugar forms a part of a belt of gold mineralization within the Dawson Range and as such a study of its lithology, alteration, and mineralization offers important information for metallogeny in the Yukon, Canada. Three mappable sub-units are recognized in the field area: a biotite hornblende quartz monzodiorite; a K-feldspar phyric hornblende biotite syenogranite; and a biotite hornblende diorite. These plutonic rocks bearing continental-arc geochemical signatures are cut by steep, west to northwest-striking andesite dikes of unknown age which themselves bear continental-arc geochemical signatures. Altered and mineralized zones coincide with fault-fracture zones that are parallel and proximal to dikes and their margins. Alteration is characterized by an early phase of calc-sodic (albite-amphibole) and potassic (pervasive biotite, fracture-controlled K-feldspar, and localized albite-biotite) alteration and a later phase of silica and sericite alteration. Gold mineralization is associated with disseminated sulphides proximal to zones of silicification and sericitization with variably sheared veins of quartz-carbonate-arsenopyrite ± pyrite ± freibergite ± stibnite ± sphalerite. Late chalcedonic quartz-carbonate and ferroan carbonate veins represent the lowest temperature expression of the hydrothermal system. Earth and Ocean Sciences, Department of Science, Faculty of Unreviewed Undergraduate
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