Exploration and planning for the future
Our greenfields exploration programmes are designed to discover new Mineral Resource that will ultimately lead to the development of new, stand-alone gold mines and support the sustainability of our business.
Nevada is delivering significant intersections that will most likely be excavated through open pit mining.
In 2022, $29m was spent on greenfields exploration. Our greenfields exploration tenements cover over 9,500km2 of highly prospective ground in six countries – Australia, Argentina, Brazil, Guinea, Tanzania, and the United States.
The Silicon and Merlin prospects in Nevada were handed over to our Beatty project team, following which the greenfields exploration team refocused its efforts on the discovery of the next significant project to add to the AngloGold Ashanti portfolio.
In the United States, following the handover of the Silicon discovery to the Beatty Project team in the first quarter of 2022, the greenfields exploration function shifted its focus to seven, 100%-owned, earlier-stage greenfields projects located elsewhere in the Great Basin of Nevada. Work completed at these various projects included prospect mapping, surface sampling and geophysical surveys. Diamond drilling is planned for the Midnight Star and CR projects during 2023.
In Brazil, 1,330 stream sediments, 1,200 soil samples and 1,060 rock chip samples were collected. From the SBB terrane in the state of Minas Gerais, four districts have been identified by stream sediment sampling. Infill sampling is in progress to define projects in these districts. At the WBC terrane, which is located in the state of Matto Grosso do Sul to the south-west of Minas Gerais, one project has been advanced and will be considered for drilling in 2023.
In Argentina, an option agreement was signed with Latin Metals for the Organullo project in Salta Province. Work completed since June 2022 included soil sampling, mapping, acquisition of various spectral data sets and community engagement. At the 100%-held El Cori project, four drilling targets were identified from surface exploration.
In Guinea, we received six reconnaissance permits for the Shira district in the Siguiri Basin of Guinea. Community engagement work has started and field exploration is scheduled for the first quarter of 2023.
In Tanzania, target generation activities continued.
In Australia, we carried out exploration work in the Laverton District and, in Queensland, greenfields exploration took place at the Chillagoe and Georgetown projects.
In the Beatty District, brownfields exploration continued at North Bullfrog and successfully defined and expanded the Silicon and Merlin targets. Elsewhere across our operations, exploration continued to add confidence to the mine plans by upgrading the Mineral Resource and to the search for new Mineral Resource with a high likelihood for conversion to Mineral Reserve.
In 2022, our brownfields exploration teams across the globe completed 799km of capital and 358km of expensed drilling at a cost of $79m and $67m respectively. Drilling started slowly at a few operations but improved as the year progressed to almost reach internal targets.
Brownfields exploration activities resulting in the most notable economic intercepts, by operation, for 2022 are listed below by region.
- Geita: The key area drilled was Geita Hill which is split into six blocks. The drilling was conducted from both surface and underground and was designed to upgrade the underground project and to prepare for mining. Other significant intercepts were drilled at Star and Comet underground at Cut 3 and Ridge 8 extending the potential of the underground complex at Star and Comet. While drilling at the Nyamulilima open pit expanded and further defined the mineralisation
- Obuasi: Drilling at Block 8, Block 10 and Sansu continued to define the limits of mineralisation and prepare these areas for mining. Late in the year, drilling started at Cote D-Or examining the potential to open a second mining area
- Siguiri: The key exploration activities were at Kounkoun (Block 3) where infill and definition drilling continue as part of the overall assessment of Block 3 as a future mining area. Drilling to extend and define the known mineralisation in Block 1 and 2 was conducted
- Kibali: Two notable drilling intercepts, at Mengu Hill and Oere, were recorded during the year
- Cerro Vanguardia: Numerous veins were drilled and later in the year emphasis moved to the northwest of the property and onto the Condor ground
- AGA Mineração, CdS: Drilling of underground opportunities at both CdS I and II delivered significant intercepts at Sangue De Boi, Mutuca, Rosalino, Pinta Bem and Pneu
- AGA Mineração, Cuiabá: Drilling to extend the depth extents of Fonte Grande Sul below 21 level continued while at a shallower depth drilling to define the satellite ore bodies continued to deliver
- Serra Grande: One significant intercept, at Angicão, was drilled during the year
- Beatty: Definition and infill drilling continued at Silicon and Merlin in Nevada. Drilling at North Bull Frog started to deliver later in the year
- Sunrise Dam: The key areas delivering significant intercepts were Frankie and Vogue as part of programmes designed to define and extend mineralisation in these areas. As is typical of the Sunrise Dam mineralisation, most drilling programmes drilled significant intercepts which reflect the nuggety nature of the mineralisation
- Tropicana: Successful drilling was aimed at the three underground projects, namely, Boston Shaker, Havana and Tropicana
While many of the significant economic intersections are for unmined underground opportunities, Nevada is delivering significant intersections that will most likely be excavated through open pit mining.
Outlook in 2023:
- Greenfields exploration will continue to concentrate on discovering the next standalone mine in one of the jurisdictions in which we operate
- Brownfields exploration will work to further the definition of the new greenfields project’s Mineral Resource. At business unit level, exploration will continue to focus on the upgrading of those high-value targets which have the greatest probability of being added to the portfolio. To aid this objective, work will also continue on the enhancement of the brownfields portfolio management system developed in 2022