Gold mineralisation at Tarkwa is hosted by Proterozoic Tarkwaian metasediments, which unconformity overlie a Birimian greenstone belt sequence. Gold mineralisation is concentrated in conglomerate reefs and has some similarities to deposits in the Witwatersrand Basin in South Africa. The deposit comprises a succession of stacked, tabular palaeoplacer units consisting of quartz pebble conglomerates. Approximately 10 such separate economic units occur in the concession area within a sedimentary package ranging from 40 metres to 110 metres in thickness. Low-grade to barren quartzite units are interlayered between the separate reef units. The Tarkwaian belt has been subject to moderate folding and at least five episodes of deformation have been recognised. Mainly tabular auriferous conglomerates are exploited, similar to those mined in the Witwatersrand Basin of South Africa, from four open pits, namely Pepe-Mantraim, Teberebie, Akontansi and Kottraverchy. During 2022, Tarkwa will finish mining the only hydrothermal style mineralisation at the Kobada open pit. The local ore body geology is dominated by the Banket series, which can be further subdivided into a footwall and hangingwall barren quartzite, separated by a sequence of mineralised conglomerates and pebbly quartzites. The stratigraphy of the individual quartzite units is well-established with auriferous reefs interbedded with barren immature quartzites. The units thicken to the west and current sedimentological param ........

Four large open pits currently exploit the stacked narrow auriferous conglomerates. Tarkwa has an ore stockpile and ‘spent ore’ on the south heap leach (SHL) pad included in Mineral Resources and Mineral Reserves. Using open-pit, conventional drill and blast with truck and shovel methods, mining operations are carried out using contractor mining. Mining occurs from several pits, which haul to the processing facility. Blast restrictions are applied to the Teberebie Cut 4 pit only. Slope stability has been supported by effective wall monitoring and blasting practices. In Q3 2021, Gold Fields initiated a scoping study to evaluate LoM expansion opportunities at Tarkwa. The study is investigating the potential to reduce unit mining costs through increased equipment size and alternative mining methods, with the ultimate objective of expanding the economic pit’s footprint and increasing the Mineral Reserve and life at Tarkwa. The study is focused on the following key elements: • Mining: Evaluation of pit expansion potential with reduced unit mining costs • Tailings: Storage alternatives, logistics and costs to enable additional ore processing • Infrastructure: Identification of mining and processing infrastructure potentially impacted by Akontansi pit expansions and estimation of relocation/replacement costs • Communities: Identification of communities potentially impacted by pit or tailings expansions and assessment of best possible relocation options and costs ........

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Ore is processed through a conventional gold recovery plant, consisting of two gyratory crushers with one gyratory crusher followed by an additional two-stage crushing circuit, both feeding a SAG/ball mill circuit, thickeners and twin CIL circuits. Gold is recovered from a gravity recovery circuit and the CIL carbon elution circuit pregnant solution by electrowinning and smelting in an induction furnace. The initial development, Tarkwa Phase 1, was completed in April 1998 processing 4.7 million tonnes per annum (Mtpa) heap leach feed ore. An expansion, Phase 2, was completed in July 1999 increasing ore production to the heap leach to 7.2Mtpa. Process improvements and optimisations resulted in the throughput increasing to 9.4Mtpa. In August 2000, GFGL acquired the northern part of the Teberebie lease. These facilities increased ore production to the heap leach to 16Mtpa. Cyanide addition ceased on the south heap leach in October 2012 with leaching continuing for a period thereaf ........