Browns polymetallic ore deposit "sulfide" resources. The oxide resources consist of supergene or weathered sulfide ore where the ore mineralogy is dominated by metal oxides, hydroxides, clays and carbonates after the original sulfide mineralogy. The Browns deposit is currently being developed as a major base metals mine by Compass Resources NL, an Australian public company, in joint venture with Hunan Nonferrous Metals Corporation, a Chinese government company. The mine is due to be complete in August 2008, after suffering cost escalation and construction delays, and will produce 15,000 tonnes of copper, 4,000 tonnes of cobalt and 4,000 tonnes of nickel per annum, with a
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