Brownfields exploration at existing assets
Near-mine (brownfields) exploration is key to Gold Fields’ strategy and has played an important role in building and maintaining a robust production profile across the regions. We believe brownfields exploration, which includes resource definition drilling but not grade-control activities, is critical for regional growth. It offers one of the lowest-cost opportunities for adding ounces and improving cash-flow, specifically on a per-share basis. This is particularly true for our Australian assets, where the average cost of Mineral Reserve ounce addition was US$51/oz for the three-year period from 2021 to 2023 – making it an extremely efficient use of capital.
Brownfields exploration allows Gold Fields to leverage our operational infrastructure and regional management teams and enables us to take advantage of our operational capabilities, including our proven ability to develop and mine orogenic ore bodies.
In 2023, Gold Fields spent US$102m (US$95m excluding Asanko, which we sold in March 2024) on brownfields exploration (2022: US$107m (US$100m excluding Asanko)), which supported a total of 299km (249km excluding Asanko) of drilling (2022: 420km (354km excluding Asanko)). Spend and drilling related to the Windfall project has not been included in these figures.
We incurred the majority of this spending – US$56m (A$84m) (2022: US$56m (A$81m)) – at our Australian mines. Our exploration spend in Chile was US$30.2m in 2023 (2022: US$31.9m) and US$12.7m (US$5.6m excluding Asanko) in Ghana (2022: US$16.1m (US$9.4m excluding Asanko)).
For 2024, we have planned US$84m for near-mine exploration and Mineral Resource conversion (not including Asanko or the Windfall project). Of this, US$59m is expected to be spent at our Australian operations, US$21m at Salares Norte in Chile and US$3m at Tarkwa in Ghana.
There is an unbudgeted, success-dependent proposal for Tarkwa of US$11.4m that will be reviewed based on the results of drilling in Q4 2023 and throughout 2024.
The details of the near-mine exploration activities at our Australian operations follow.
Gruyere
Gold Fields spent A$2.4m (US$1.6m) in near-mine exploration at Gruyere in 2023. The mine’s attributable Mineral Reserves (50% basis) decreased by 9% to 1.8Moz, in line with expectations and the life-of-mine plan. Mineralisation is open at depth and Gold Fields and its JV partner Gold Road Resources are reviewing the potential for moving underground in the future.
Gruyere – Mineral Reserves reconciliation (50%) (koz)
St Ives
At St Ives, total 2023 exploration spend amounted to A$39m (US$26m). Attributable Mineral Reserves decreased by 4% to 2.6Moz, net of depletion, with the Invincible complex continuing to grow, both laterally and at depth, which offset a large proportion of mining depletion.
St Ives – Mineral Reserves reconciliation (koz)
Granny Smith
Total exploration spend at Granny Smith was A$20m (US$13m) in 2023. Attributable Mineral Reserves increased by 12% net of depletion to 2.4Moz. Mineral Reserve growth occurred primarily in Zone 135 and Zone 150 of the Wallaby underground mine.
Granny Smith – Mineral Reserves reconciliation (koz)
Agnew
We spent A$23m (US$16m) on near-mine exploration at Agnew during 2023. Agnew was unable to replace Mineral Reserves after depletion during the year, with Mineral Reserves decreasing by 20% to 0.9Moz. As model cut-off dates were brought forward in 2023, results from drilling in H2 2023 have not been included in the model update and estimation.
Agnew – Mineral Reserves reconciliation (koz)
