The Betze-Post mineralization, the largest deposit in the Carlin Trend, is subdivided into sub-deposits which, from east to west, are the Deep Post, Post, Betze, West Betze, and Screamer. Other zones within the pit are North Betze, West Barrel, and North Screamer.

Overall, the open pit deposits consist of five stacked zones which, when combined, average 500 ft thick and 600 ft wide but may attain a thickness of 700 ft, a width of 1,100 ft, and a length of 3,400 ft.

Five generations of pyrite mineralization have been recognized at the Betze-Post open pit. Early stages of diagenetic pyrite, and coarse grained pyrite in the metamorphic aureole of the Goldstrike diorite, are barren. Early hydrothermal, very fine grained pyrite and marcasite grains of the third generation are coated by a 25 µm thick rind and cut by micro-veinlets of arsenic and gold bearing pyrite of the fourth generation. Barren, late hydrothermal coarse grained pyrite and marcasite is accompanied by barite and stibnite. Sulphides make up approximately 5% by weight of the ore, locally up to 20%.

The gold bearing arsenian pyrite may be subdivided into coarse grained sulphides at ±200 µm diameter and fined grained at 10 µm to 20 µm, with the latter carrying proportionately much more gold. Gold at 0.05 µm to 0.1 µm is occluded in the iron sulphides. Approximately 10% to 20% of the gold is free, 20% to 30% is held in the fine grained pyrite/marcasite, a few percent is contained in coarse pyrite, and the balance is in very fine pyrite associated with clay.

Barrick’s Betze-Post open pit is a large scale operation utilizing a traditional truck and shovel fleet.

Pit dimensions: 3.3km long x 2km wide x 600m deep (w/out backfill) and Typical bench height 6-13m.

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.