Wernecke Breccia-associated iron oxide-Cu-Au mineralization, Yukon, Canada

Abstract

Iron oxide-copper-gold mineralization occurs within Early Proterozoic Wernecke Breccia and adjacent metasomatised country rock. Multiple phases of mineralization are evident and occur as disseminations, breccia matrix and veins. Brecciation is associated with widespread albite andlor potassium feldspar alteration, local ankerite-magnetite±hernatite alteration and abundant carbonatization. Breccia emplacement took advantage of pre-existing crustal weaknesses such as faults, fold axes and joints. Breccias occur as large zones with crackle brecciated contacts and smaller "dyke-like" bodies with sharp contacts. Mineralization associated with Wernecke Breccia is included within the Proterozoic iron oxide (Cu-V-Au-REE) class and is similar to deposits in other areas including those in the Cloncurry and Olympic Dam districts of Australia.