Located approximately 300 km west-southwest by road from the capital city Accra, and 80 km west by road from the port of Takoradi.
Adamus Resources Limited is an operating gold mine located in the Nzema area of Ghana's Western Region, approximately 300 km west-southwest of the capital, Accra, and 80 km west of the port of Takoradi.
Adamus was Nguvu Mining's first acquisition, completed in the last quarter of 2016, and remains a flagship operation delivering consistent production, strong safety performance and deep community engagement.
The operation has received multiple industry honours, including Best Mining Company, Best Community Outreach Project and National First Aid & Safety Champion.
In detail
Production, geology & exploration
Conventional open-pit mining by owner mining, with ore processed on site using Carbon-in-Leach technology.
Oxide ore throughput
2.1 Mtpa
Transition & fresh ore throughput
1.6 Mtpa
Workforce
1,228
Employees from local communities
59%
The mine commenced initial mining operations in November 2010 and commercial production in April 2011. The mine employs the conventional open pit mining method, with mining activities carried out by owner mining.
The mined ore is processed by Carbon-in-Leach (CIL) technology. The processing plant is designed to treat oxide, transition and primary ores. The design throughput treatment rate depends on the hardness of the ore, at 2.1 Mtpa for the softer oxide ore and 1.6 Mtpa for the harder transition and fresh ore.
The mine has a workforce of approximately 1,228 people, made up of 1% expatriates and 99% Ghanaians, of which about 59% come from the local communities.
Birimian Supergroup host rocks on the south-western margin of the Ashanti Belt.
The major gold deposits in Ghana are hosted by Palaeoproterozoic rocks of the West African Craton. These include the Birimian Supergroup, a series of meta-volcanic and meta-sedimentary rocks; the Tarkwaian Group, comprising fluvial meta-sedimentary rocks; and various gabbroic to granitic intrusives.
Gold mineralisation within the Birimian Supergroup is associated with mesothermal quartz veins and is structurally controlled, while both mesothermal shear-hosted and palaeoplacer gold deposits occur in the Tarkwaian Group. The project area is underlain by Birimian Supergroup rocks with minor granitic intrusions, bounded by large granitoid bodies to the west and east, and poorly defined areas of the Tarkwaian Group in the east.
Metamorphic grade of the Birimian rocks is greenschist facies, with local amphibolite facies aureoles around granitoid plutons. Recent work in the southern Ashanti region suggests that the greenschist facies is widely retrograde after amphibolite facies conditions. Both belt and basin packages are highly deformed, with widespread isoclinal folding and regional bedding-parallel cleavage attributed to regional north-west to south-east compression during the peak of the Eburnian Orogeny (c. 2100 Ma).
Regional north-east striking shear zones parallel to the belt margins are also assumed to have developed during peak Eburnian, and appear to be fundamentally important in the development of the Birimian gold deposits for which Ghana is well known — such as Ashanti, Prestea-Bogosu, Konongo and Bibiani. ARL’s Nzema Gold Project covers the south-western margin of the famous Ashanti Belt.
The Nzema Gold Mine is located at the southern end of one of five parallel, evenly spaced belts of folded Birimian metalavas known as the Ashanti Belt. The deposits have been identified as three main groups: the Salman Trend, the Anwia (Adamus) deposit, and the satellite deposits.
Major gold deposits of Ghana, with the Nzema Gold Mine on the Ashanti Belt.Regional geology map of the Nzema Gold District.
A discovery target of at least 350,000 oz, pursued through the Nzema exploration programme.
Land package
369.95 km²
Mining leases
4
Prospecting licences
8
Untapped Salman sulphide resource at 1.80 g/t Au
973 Koz
The Nzema Gold Project is a land package of about 369.95 km² located in south-west Ghana, made up of four mining leases and eight prospecting licences, with two joint-venture permits.
A vast exploration potential exists on the mining leases and the surrounding prospecting permits, which are currently being explored for economic gold deposit discoveries to extend the life of mine.
A total resource of 973 Koz @ 1.80 g/t Au of untapped refractory Salman ‘sulphide’ ore exists. Metallurgical studies to find an appropriate treatment method for the sulphide ore are underway.
South-west Ghana geology, showing the Nzema Gold Project.
Nzema Project — summary geology & mineralisation
The Nzema Project area straddles the Ashanti Belt–Kumasi Basin margin. It is currently the only large-scale operating mine south of the Prestea–Iduapriem mines. The geology of the project area is dominated by alternating thick bands of greywacke and phyllite to the west of the Ashanti Fault. Some of the greywacke–phyllite contacts are sheared, with gold mineralisation often localised in structures associated with these shears and faults. Further west into the basin, the phyllite–greywacke units have been multiply folded, with gold mineralisation often hosted in fold-related structures. Typical fold-related gold deposits in the Nzema land package include the Adamus deposit, hosted at a fold limb, and the Nfutu deposit, hosted at a fold nose.
The dominant rock types to the east of the Ashanti Fault are meta-volcanics, volcaniclastics and belt sediments. The main structures known to occur to the east of the Nzema Project area are the NNE-trending Avrebo Shear, which hosts about 40 Koz Indicated resource, and extensive volcanics–granitoid margins with some untested geochemical anomalies of interest. Several granitoid bodies of various shapes and sizes have intruded both the basin sediments and the volcanics and volcaniclastics units. The intrusive–sediments and volcanics contact areas are part of the potential areas to receive exploration attention.
Defined exploration targets over geology
Defined exploration targets over geology.
The current Nzema Project pipeline of exploration targets was developed by integrating existing geochemical, drilling, geophysical and geological data.
Target generation work — continuing data review, field and pit mapping, rock and soil sampling, and ground magnetic surveys — is being carried out to define drilling targets for deposit discoveries and life-of-mine extension.
Drill testing of some targets commenced in January 2022. Successful targets would be advanced to the resource definition stage, with a mineral resource estimate to be delivered for mine planning.
The objective is to progressively produce 350 Koz and replace depleted reserves at a discovery cost below US$20/oz.
The Nzema exploration strategy for life-of-mine extension
1. Development of existing assets (Salman–Nfutu–Adamus deposits and surroundings) for incremental ounces
Salman Trend remnant oxide & refractory ores
Drilling for oxide ore along the Salman Trend focused on targets in the dilatant zone, with a mineral resource estimate to follow.
Salman Deeps — test drilling for extensions of the sulphide ore at depth was completed in January 2022. The outcome confirmed extensions of the ore shoots at approximately 100 m below the current resource. Infill drilling for strike and up-dip extensions of the ore shoots is planned.
Nfutu deposit (incremental ounces conversion)
The initial phase of drilling confirmed the down-plunge extension of the medium- and high-grade ore shoot to the south-east, defining a resource of 327 Kt @ 1.47 g/t Au.
Adamus pit (incremental ounces conversion)
Deep drilling is planned to test for potential underground extensions of gold mineralisation.
2. Development of early-stage prospective targets
Focus on untested exploration targets within a 5–10 km radius of the processing plant that have the potential to yield an economic mineral resource estimate.
Priority targets include Gama, Mamposo, Bernard West and the Boanome East extension, and Nfutu West, among others.
3. Build a strong social licence for smooth operation
Provide employment and other job opportunities for local people.
Comply with environmental and safety requirements in the catchment areas.
Provide social support to the communities directly impacted by ARL’s mining operations.
Salman ‘sulphide’ project — potential for resource upgrade
Salman Trend sulphide project, long section.
Potential exists for a resource upgrade of the unexploited 973 Koz sulphide resource at depth and along strike.
Existing drilling has probed the mineralisation to a vertical depth of around 100 m. The drilling campaign at the dilatant zone sought to confirm extensions of the ore shoots a further 100–150 m below the current resource; assays of one initial diamond drill hole returned 8 m @ 3.35 g/t Au.
