Tillkännagivande • Jun 13
Aura Energy Limited Provides an Update on the Mineral Resource Estimate for the Tiris Uranium Project in Mauritania
Aura Energy Limited provide an update on the Mineral Resource Estimate ("MRE") for the Tiris Uranium Project ("Tiris" or the "Project") in Mauritania. The drilling program undertaken in 2024 has delivered a major increase to the Project's Global Mineral Resources totalling 184 Mt at 225ppm for 91.3 Mlbs U3O8 at a 100ppm cut-off grade. This is a 55% increase in the contained U3O8 from the previous MRE, reported in 2023, of 113Mt at 236ppm for 58.9Mlbs[5] U3O8. This drilling program was aimed at assessing additional resource potential at Tiris East and delivered a 10.3 Mlbs or 35% increase of Measured and Indicated ("M&I") Resources, which stands at 83 Mt @ 219ppm for 39.9 Mlbs U3O8, and a 76% increase in total Inferred Resource, which stands at 102 Mt @ 229ppm for 51.4 Mlbs U3O8. The detail of the upgraded resource across the project areas. In April 2024[6], Aura completed an air core ("AC") drilling program of 2,995 holes for 15,262 metres, a 37% increase in the total number of holes available for resource calculations, to evaluate a previously announced exploration target of between 8 Mlbs and 32 Mlbs[7]. The Mineral Resource increase of 32.4 Mlbs U3O8 exceeded the upper end of the exploration target range, providing strong support to Aura's exploration methodology, and is a strong indication to the mineralisation potential that may be available in regional leases that are currently under application[8]. In addition to targeting extensions to known mineralisation, and testing previously un-drilled radiometric anomalies around Tiris East, the program considered several conceptual targets over low-level radiometric anomalies. Several of these conceptual targets returned very positive results, further increasing exploration potential of the area. This is a major change from previous exploration in the area. Mineral Resource estimates were undertaken utilising Multiple Indicator Kriging ("MIK") estimation methodology and recoverable Mineral Resources reported using a 10x10x1m Selective Mining Unit ("SMU"). The Competent Person for the 2024 Tiris Mineral Resource Estimates is Mr. Arnold van der Heyden of H&S Consulting Pty Limited. The Tiris Uranium Project is in north-eastern Mauritania, approximately 1,200km northeast of the capital, Nouakchott. Access is via Zouérat, 744 km by bitumen road and then a further ~700km on hardpan desert roads (Figure 1). The Mineral Resource Estimate ("MRE") is based on drilling conducted on two Mineral Exploration permits held 100% by Aura Energy: 562B4 Oum Ferkik, 2365B4 Oued EL Foule Sud, and on two Exploitation permits: 2492C4 Oued El Foule, 2491C4 Ain Sder held by Tiris Ressources SA (85% Aura Energy). Oum Ferkik is under application for conversion to an Exploitation Permit. Global Mineral Resources at Tiris currently stand at 184Mt at 225ppm for 91.3Mlbs U3O8, including Measured and Indicated Resources of 83Mt @ 219ppm for 39.9Mlbs U3O8 and Inferred Resource of 102Mt @ 229ppm for 51.4Mlbs U3O8 (applying a 100ppm U3O8 cut-off grade). The recently released FEED[9] study defined a near-term low-cost 2 MlbsU3O8pa uranium project with a 17-year mine life and very strong economics; NPV8 US$ 388 M, IRR 36% and 2.5 year pay-back at a US$80/lbU3O8price. The Project has significant optionality in the design, allowing expansion to expand to accommodate growth in Mineral Resources. The Tiris East Mineral Resources are very shallow (less than six metres deep), free dig mineralisation, with no crushing or grinding that has proven exceptional beneficiation characteristics which gives rise to Tiris' robust economics. The Tiris Uranium Project lies in the north-eastern part of the Reguibat Craton, an Archaean (>2.5 Ga) and Lower Proterozoic (1.6-2.5 Ga) aged complex composed principally of granitoids, meta-sediments and meta-volcanics. The resources lie within Proterozoic portions of the craton. This part of the craton generally consists of intrusive and high-grade metamorphic rocks of amphibolite facies grade. In addition to the Archaean and Paleoproterozoic basement rocks, two principal types of Cainozoic surficial sediments occur; Hamada (sand and outwash fan material) and Cailloutis (flat lying calcrete layers, typically 1 to 3 metres thick, in places partially silicified) which in this area stand out as small mesas up to a few metres above the surrounding land surface. Several small uranium occurrences were known in the Reguibat Craton from exploration during the 1950's. All the resource zones are generally at less than 5m depths lie beneath flat land surfaces covered by surficial hamada and thin aeolian sand deposits. This shallow overburden largely covers the basement rocks, which only appear as scattered outcrops. The uranium resources generally lie either within weathered, partially decomposed red granite or in colluvial gravels developed on or near red granites. Small portions occur in other rock types such as meta-volcanics and meta-sediments. The resources are believed to have developed within shallow depressions or basins, either within weathered granitic rocks or where colluvial material has accumulated in desert sheet wash events. The pebbles within the gravels are generally unweathered fragments washed in from the nearby exfoliating granites and other crystalline rocks, mixed with sand, silt, calcrete, gypsum and yellow uranium vanadates. The gravels and weathered granite occur at surface or under a very thin (<30 cm) veneer of wind-blown sand and form laterally continuous, single, thin sheets overlying fresh rock, usually granite. The uranium mineralisation generally forms thin shallow horizontal tabular bodies ranging in thickness from 1 to 12 m hosted in weathered granite and granitic sediments. It is inferred that the deposits were formed by near-surface leaching of uranium from the uraniferous red granites by saline groundwaters during the wet Saharan "pluvial" periods. There have been several periods over the past 2.5 million years, the most recent ending only 5,900 years ago. Evaporation during the subsequent arid periods caused the precipitation of uranium vanadates, along with calcium, sodium and strontium carbonates, sulphates and chlorides. The host material at Tiris is granitic gravel or weathered granite containing powdery calcium carbonate (calcrete) and sulphates. Although the Tiris mineralisation is associated with calcium carbonates, it differs from other well-known calcrete uranium deposits such as Langer Heinrich and Yeelirrie, in that they are river valley-fill deposits. The Tiris deposits have formed in shallow depressions in unconsolidated and uncemented gravels and in partially decomposed granites. In Namibia and Western Australia, the mineralisation is typically within calcareous clays or massive hard calcrete which forms below the water table, often at several levels related to the changing positions of the water table.