The Goldstrike deposits are Carlin style deposits. Carlin deposits comprise stratabound disseminated gold mineralization hosted by Silurian-Devonian carbonate rocks that have been metamorphosed to varying extents. The deposits are hydrothermal in origin and are usually structurally controlled. The carbonate host rocks are part of an autochthonous miogeoclinal carbonate sequence exposed as tectonic windows beneath the Roberts Mountains allochthon.

Meikle is a high-grade ore body which is mined by transverse longhole stoping, underhand drift and fill mining methods.

The Goldstrike property has two processing facilities: an autoclave installation, which was originally designed to treat the property’s non-carbonaceous sulfide (refractory) ore; and the roaster, which is currently used to treat the property’s carbonaceous ore (whose active carbon content responds poorly to autoclaving). The original combined installed capacity of these two facilities was approximately 27,000 to 30,000 tonnes per day. After the implementation of the thiosulfate modifications described below, the combined installed capacity of the two facilities is expected to be approximately 26,000 to 27,000 tonnes per day. These process facilities treat the ore from Goldstrike’s open pit and underground mines, as well as ore from other Barrick properties. Gold recovered from the ore is processed into doré on-site and shipped to outside refineries for processing into gold bullion.

The TCM technology uses calcium thiosulfate to leach the gold after pressure oxidation rather than cyanide. Resin is used to collect the dissolved gold rather than activated carbon. First gold from the TCM process was produced in November 2014, following completion of construction of the first phase of the TCM facility. After a staged start-up, the autoclaves are expected to reach full production capacity of 12,000 tonnes per day in 2015. The new TCM circuit will allow the autoclaves to continue to operate through the remaining life of the mine. As a result, Goldstrike expects to be able to process stockpiled carbonaceous material earlier than anticipated and increase its capacity to process ore transported to Goldstrike from other properties. The expected average annual contribution is approximately 350 to 450 thousand ounces of production (including Cortez ore processed at Goldstrike) in the first full five years following implementation of this process.