Antler’s Erongo Gold Project comprises four licenses (EPL 5455, 6162, 7261 and 6550) under option and a further five (EPL 7854, 7930, 7960, 8010 and 8042) under application, for a total landholding of approximately 83,576ha (835.8km2) and is located in central Namibia near the towns of Usakos, Karibib and Omaruru. The project covers areas of the Navachab-Damara Belt, which is highly prospective for gold, and overlies similar lithologies and structures as the known Namibian Gold mines (QKR’s Navachab and B2 Golds’ Otjikoto) as well as the recent Twin Hills discovery.
Antler used a systematic and diligent Mineral Systems Analysis approach to put together its Erongo Gold project. The mineral systems approach to mineral deposit genesis provides a framework that considers all the geological processes that control the formation and preservation of major mineral deposits. Preliminary work by Antler focused on re-interpretation of the government aeromagnetic data, which lead to the discovery of a large, previously unmapped, deep regional structure – now named the Kranzberg Fault Zone. The Kranzberg Fault stretches across Antler’s Central Project from the Kranzberg Dome, in the southwest, through Antler’s EPL 6162, 7261 (under option) and 7854 (under application) and around Antler’s Etiro Dome property (EPL 6550 under option) in the northeast. This structure can be traced over 50km and has several historically mapped gold anomalies along it and on splays leading off it.
Our Erongo Gold Project is located approximately 130 km north-west of Namibia’s capital city Windhoek and benefits from Namibia’s well-established infrastructure of paved highways, railway, power and water. Namibia is mining-friendly and generally regarded as one of the continent’s most politically and socially stable jurisdictions.
Geology of the Erongo Gold Project
The Erongo Gold Project is hosted by rocks within the Southern Central Zone of the Damara Orogen. This terrane comprises mid Proterozoic granitic basement inliers, overlain by metamorphosed late Proterozoic arkoses, shelf carbonates, turbidites and minor volcanic rocks that have been intruded by numerous granites and pegmatites.
The bulk of the Project area is underlain by meta‐sedimentary rocks of the Nosib Group meta‐arkoses (Etusis Formation) or the stratigraphically younger Swakop Group marine carbonates and meta‐turbidites comprising the Arandis Formation (biotite schist, minor quartz schist calc‐silicate rock and amphibolite), the Karibib Formation (dominantly dolomitic and calcitic marbles with minor calc‐silicate) and the overlying Kuiseb Formation (schistose quartz feldspar mica meta‐greywacke and meta‐pelite). Glaciogenic mixtites of the Chuos and Ghaub Formations have limited exposure in the project area. The Swakop Group sediments have been intruded by a series of syn‐, late‐syn‐ and post‐tectonic granite and pegmatite bodies.
The Erongo Gold Project is straddled by the magnetically defined regional scale Omaruru and Welwitschia Lineaments in the west and the Abbabis and Erongo Lineaments in the east. These lineaments are interpreted to be important tectono‐stratigraphic boundaries associated with changes in sedimentology, structure and type of granitic intrusion observed in the Damara Orogen and have known association and control with uranium and other forms of mineralization. The structural setting of the Project area is fairly complex with sediments deformed during poly‐phase deformation and metamorphosed to upper greenschist‐amphibolite facies.
The structural geology of the Erongo Gold Project area is dominated by features typical of the Southern Central Zone of the Damara Belt; Abbabis Basement and/or basal Damara meta‐sedimentary rocks in the cores of dome and anticlinal structures and regional synclinal structures with thick packages of Kuiseb Formation schists occupying these synclines. The larger, earlier folds tend to have fold axes with a north‐east, south‐west direction, parallel to the Omaruru Lineament, and these were subsequently deformed into open basin and dome structures or boudinaged in the more competent lithologies. Later cross cutting lineaments parallel to the Welwitschia Lineament are also evident. These NNE trending structures appear to be loci for mineralised fluid movement.
The gold mineralization in the Damara Belt in general, including Otjikoto, Navachab, Ondundu, Onguati and Twin Hills all share various similarities including stratigraphic position and relationship to regional and local structure. A significant relationship is observed between gold and quartz ‐ sulphide veins hosted dominantly in schists and calc‐silicate rocks and to a lesser extent within marbles and dolomitic marbles, as seen at Navachab (and associated satellite deposits). These discoveries and the historical gold deposits and occurrences, in general, highlight the Central and Northern Zones of the Damara Orogen, as a prime target for further discovery.
Antler recently discovered the previously unmapped Kranzberg Fault Zone. The Kranzberg Fault Zone is an arrangement of ENE and NNE trending thrusts and faults that can be traced for over 50 km and may have developed by reactivation of the larger Omaruru, Onguati and Abbabis Lineaments during the transpressional D3 / D4 Damaran deformation. Structures associated with the D3 / D4 event have been shown to be important conduits for hydrothermal fluids and highly prospective for gold mineralisation, as demonstrated by the Navachab Gold Mine and Osino’s Twin Hills Project.
This fault zone is parallel to and shares many similarities to the Karibib Fault Zone which hosts Osino’s Twin Hills Project. The associated Kranzberg Gold Trend, with peak historical rock assay values up to 80 g/t, stretches across Antler’s Central Project from the Kranzberg Dome, in the southwest, through Antler’s EPL 6162 and 7261 and around Antler’s Etiro Dome property (EPL6550) in the northeast. In total, Antler holds approximately 20 km of strike length along this gold trend.
The Kranzberg Gold Trend contains a number of historical smaller scale mines and prospects including Onguati, Brown Mountain and Western Workings (all previously worked during the 1950’s and 1960’s). In addition, a number of significant gold in soil and gold in rock anomalies have been historically defined. These gold anomalies are located along the Kranzberg Fault Zone within Antler’s EPLs 7261, 6162 and 6550 and contain gold in soil assays of up to 7000 ppb gold and gold in rock assays of up to 80 g/t gold, all against a background of less than 5 ppb gold. Note these results are historic and have not been verified by Antler. The historic mines, prospects and soil anomalies occur in association with folds; faults; fault splays and jogs; and late- to post-tectonic leucogranite intrusions, all typical of fertile orogenic belts.
The Kranzberg Gold Trend is located in the saddle region of a moderate-to-gently inclined doubly plunging anticline with associated large-scale, deep penetrating, crustal structures of the Kranzberg Fault Zone. Interpretation and delineation of this fault zone was only made possible by Antler’s geophysicists through reprocessing of the Government regional aeromagnetic data taking cognisance of the negative impact of magnetic attenuation due to increased survey ground clearance required over the Erongo Mountains in the north of the Central Project. The Erongo Mountains are a post-Karoo aged volcanic caldera that tower 1,000 meters above the flatter plains of the Central Project. Downward continuing and reprocessing the data to mitigate the impact of non-ideal survey heights in conjunction with the initial field visit has resulted in the identification of this previously unrecognized but significant Kranzberg Fault Zone.
Antler will be focusing its efforts on advancing these two high potential Projects;