WERNECKE BRECCIA: PROTEROZOIC IOCG MINERALISED BRECCIA SYSTEM, YUKON, CANADA

At least 65 iron oxide-copper-gold ± uranium ± cobalt (IOCG) prospects are associated with a large- scale Proterozoic breccia system in north-central Yukon Territory, Canada. The breccia system, known as Wernecke Breccia, consists of numerous individual breccia bodies that occur in areas underlain by the Early Proterozoic Wernecke Supergroup, an approximately 13 km-thick deformed and weakly metamorphosed sequence of sedimentary rocks. The IOCG mineralisation occurs as multiple episodes of veining and disseminations within and peripheral to the breccia bodies. Brecciation and mineralisation are associated with extensive sodic and potassic metasomatic alteration overprinted by pervasive carbonate alteration and are spatially associated with regional- and local-scale faults. The scale of brecciation in this area is similar to that in other large-scale breccia provinces that contain signifi cant mineralisation, e.g., Cloncurry and Gawler districts of Australia that host the Ernest Henry and Olympic Dam deposits. Implied similarities between the two areas and the possibilities for signifi cant discoveries have led to the renewed exploration interest in the Wernecke Breccias.