North Mara is located in northwestern Tanzania, in the Tarime District, 210 km northeast of Mwanza. Situated in the Mara-Musoma Greenstone Belt, mineralization occurs between a foliated volcano-plutonic-sedimentary sequence to the north and largely sandstones to the south, generally steeply dipping to the south. Over a hundred small artisanal workings are scattered around the area. The project site was first explored by Afrika Mashariki Gold Mines in 1993 and by 1996, a Resource of 1 Moz was defined, feasibility study was completed, and mining licenses were granted. The company was subsequently acquired by East African Gold Mines and first gold was poured in 2002. The project was purchased by Placer Dome in 2003, which itself became acquired by Barrick in 2006. At the time of publication of the technical report, North Mara had processed 24.3 Mt at a grade of 3.07 g/t to produce 2.0 Moz gold.
North Mara consists of three open pits and an advanced exploration deposit. The open pits are mined as conventional shovel and truck operations. The pits are fairly small and due to a high strip ratio of 8.83, unit cost of open pit mining is relatively high at $23.82/t-milled. This results in cutoff grades ranging from 0.96 g/t to 1.18 g/t. The Complex is planned to have a combined throughput of 2.9 Mtpa targeting 250 koz per year. LOM average recovery is 86.1%. As a producing mine, North Mara is under no obligation to disclose project economics. Mining Momentum has used the LOM plan and costs presented in the technical report to estimate a Pre-Tax Cashflow of US$918 M and US$552 M discounted 10% using the Reserve gold price of US$1,200/oz. This includes the $50 M closure cost mentioned in the technical report, applied to the end of mine life.
| Tonnes (Mt) | Grade (g/t) | Contained (Moz) | |
|---|---|---|---|
| Reserve | 35.6 | 3.05 | 3,485 |
| OP | 32.8 | 3.15 | 3,323 |
| UG | 0.0 | 0.00 | 0 |
| Stockpile | 2.8 | 1.79 | 162 |
| M+I | 16.0 | 2.80 | 1,440 |
| OP | 12.7 | 2.35 | 956 |
| UG | 3.3 | 4.52 | 484 |
| Inferred | 1.6 | 2.56 | 128 |
North Mara is not a contender for the coveted Tier 1 designation, but remains a solid Tier 2 performer. Due to steeply dipping and narrow vein nature of the orebody, strip ratio quickly increases, hence the fairly small pits. By managing blending strategy, the operation maintains a consistent mill feed of 2.9 Mtpa. The advanced exploration Komarera deposit is projected to be a small, high-grade pit, useful for blending, but with only a 3.7 Mt Resource, it is not particularly impactful in extending mine life. Based on the technical report, mining should conclude in 2022 with two additional years of stockpile processing. The existing pits have 10 Mt sitting in M+I Resource, although it is unsure whether conversion of these Resources is possible. 3.3 Mt of M+I Resource has been defined underground which could add a couple years of mine life. Underground exploration holds promise, since steeply dipping deposits are often not well defined by surface drilling, but hold potential at depth, and are amenable to underground mining. Mining Momentum estimates North Mara to operate until the latter half of the 2020s.
The information presented above does not constitute investment advice. This is a summary from the NI 43-101 Technical Report effective December 31, 2011 (INSERT), with commentary from the author. Statements above do not represent the views of Barrick Gold. If any discrepancies arise, the information contained within the NI 43-101 are official and final. For latest depletion data, please refer to the AIF update.