Hydrothermal alteration, mineralization and exploration potential of the Mars alkalic copper-gold-molybdenum porphyry occurrence, Laberge map area (105E/7), Yukon
Description
The Mars property occurs on the southwestern margin of the Teslin Crossing pluton, a composite intrusion of intermediate, alkalic composition that was emplaced into sedimentary rocks of the Middle Jurassic Tanglefoot formation at about 175 Ma. Exposed alteration and mineralization define a northwest-trending zone 2.8 by 1.5 km. New field and petrographic data document a core zone dominated by sodic and magnetite-rich alteration, surrounded by more extensive calc-potassic alteration; each assemblage contains disseminated and fracture-hosted copper-gold mineralization. Subzones of younger quartz veins with strong copper-molybdenum±gold mineralization are widely distributed. Sericitic and propylitic alteration is minor and weakly mineralized. The system has low sulphide mineral content with a high ratio of chalcopyrite to pyrite. Hornfels in the Tanglefoot formation has stronger pyrite-pyrrhotite and also carries copper-gold mineralization. The Mars system is a silica-oversaturated alkalic copper-gold-molybdenum porphyry deposit with strong similarities to the Cadia and Goonumbla deposits in Australia.