Pierina

Overview

The Pierina mine is located in the Andean Cordillera in the Department of Ancash in north-central Peru, approximately 10 kilometres northwest of the city of Huaraz, at an altitude of approximately 4,100 metres.

Pierina is an open-pit, truck-and-loader operation. Ore is crushed and transported through an overland conveyor to the leach pad area. Run-of-mine ore is trucked directly to a classic valley-fill type of leach pad.

In 2011, Pierina produced 152,000 ounces of gold at a total cash cost of $825 per ounce. Proven and probable mineral reserves as of December 31, 2011 were estimated at 771,000 ounces of gold and 23.2 million ounces of silver.

As a result of rising gold prices, and based on mineral reserves Pierina’s mine life has been extended to the end of 2016.

Location

The Pierina mine is located in the Andean Cordillera in the Department of Ancash in north-central Peru, approximately 10 kilometres northwest of the city of Huaraz, at an altitude of approximately 4,100 metres.

Ancash – ‘blue’ in the local Quechua language - is a region in northern Peru situated at the shores of the Pacific Ocean. It also encompasses part of the the Andean Cordillera and of its high plateaus.

Huaraz is the Ancash capital city located at 3,052 m altitude. From the early years of their conquest the Spaniards developed the regions mineral wealth mostly by enslaving the local population.

Geology & Mineralization

The Pierina Belt contains structurally controlled gold, silver, lead, zinc and copper mineralization in the Calipuy volcanics. A 70 km long belt of hydrothermal alteration is associated with the known deposits. The Pierina deposit is underlain by basal andesitic lavas and overlying rhyodacitic pumice and lithic tuffs. Dominant structures in the deposit trend NNW, WNW and NE.

Gold mineralization is associated with vuggy silica alteration and is dominantly hosted in the rhyodacitic pumice tuff with lesser amounts in the overlying lithic tuff and the underlying andesite. The silica altered zone is flanked by quartz-alunite and argillic alteration. Ore-grade mineralization in the pumice tuff occurs over intervals of more than 260 m. The area of currently known mineralization measures approximately 450 m wide by 1,200 m long and is open to the southeast. Significant silver mineralization is present. The highest grades of silver (to 300 g/t) are located in the north end of the deposit. Over 95% of the mineralization is oxide.

The December 31, 2011 mineral reserves were calculated at 61.08 Mt at 0.37 g/t gold for 771,000 oz gold.

Mining & Operation

Pierina is a conventional truck and shovel mining operation.

The ore body is being developed as a conventional open pit using 30-foot benches. The life-of-mine strip ratio of the Mine is 1.3:1.

Ore is crushed and transported through an overland conveyor to the leach pad area. Run-of-mine ore is trucked directly to a classic valley-fill leach pad.

Processing

The leach process is a classic valley fill method. The ore is stacked in a lined containment area behind a retention dam.

Cyanide is sprinkled on top of the low grade ore and the resulting pregnant (gold bearing) solution is then redirected to a gold recovery circuit.

Environment & Community

Barrick’s investment in local communities is already making a difference. Pierina mine has had a profoundly positive impact on local communities, where poverty has declined significantly since the mine opened, and literacy rates are on the rise. Over 90 percent of Pierina’s employees and contractors are Peruvians and they live in nearby communities.

Barrick is also involved with the A Roof for My Country an international non-governmental organization (NGO) whose volunteers build transitional homes side by side with the families who will live in them. In all, 335 homes will be built in 11 different communities around Barrick’s Pierina mine during the three-year program - 135 of which will be directly funded by the company.

As the region surrounding the mine suffers from deforestation Pierina mine holds a greenhouse that produces and holds 300,000 trees and plants per year. Barrick has already planted more than 1.2 million trees in the mine area.