Mount Isa Mines tetrahedrite as ore minerals along with common accessories pyrite, pyrrhotite, quartz, carbonates and graphite. Minor arsenopyrite, marcasite, chalcopyrite, valleriite, proustite, polybasite and argentite also occur. Original surface oxidized ore contained cerussite, anglesite and pyromorphite. Silver and zinc were removed from the surface oxidized zone and were deposited as supergene ore at a depth above the primary ore. Copper occurs in brecciated "silica-dolomite" rock. Primary minerals are chalcopyrite, pyrrhotite and arsenopyrite. minor amounts of cobaltite, marcasite, valleriite, chalcostibite, galena and others are reported. Smelter operations release sulfur dioxide emissions very close to the city of Mount Isa. The Mount Isa Mines
Volcanogenic massive sulfide ore deposit sulfidic sediments, similar to SEDEX ores, and is generally manganese, barium and hematite enriched, with cherts, jaspers and chemical sediments common. Most VMS deposits show metal zonation, caused by the changing physical and chemical environments of the circulating hydrothermal fluid. Ideally, this forms a core of massive pyrite and chalcopyrite around the throat of the vent system, with a halo of chalcopyrite-sphalerite-pyrite grading into a distal sphalerite-galena and galena-manganese and finally a chert-manganese-hematite facies. Most VMS deposits show a vertical zonation of gold, with the cooler upper portions generally more enriched in gold and silver. The mineralogy of VMS massive