Alligator Rivers Uranium Field
The ARUF is a world-class uranium province which is analogous to the Athabasca Uranium Province in Canada in terms of its uranium endowment and geological setting. However, in contrast to the Athabasca, the ARUF is at a relatively early phase of its exploration history, having received a fraction of the exploration expenditure of its Canadian counterpart.
The ARUF hosts the Energy Resources of Australia Limited’s Ranger Uranium Mine and Jabiluka Deposit and the historical Nabarlek Deposit. The Field’s mineral endowment, including mined resources, exceeds 500 million pounds of uranium (see Figure 5). The recent discovery of high-grade uranium by Cameco Australia Pty Ltd at its Angularli Prospect – where drill-hole WRD0084 returned intersections including 12.2m @ 1.1% U3O8 and 20.2m @ 5.2% U3O8(1) – has added to the prospectivity of the region.
In June 2014 the Company announced it had purchased Arnhem Minerals Pty Ltd, holder of 7 Exploration Licence Applications covering 2,096 km2 in West Arnhem Land (see Figure 4). This acquisition has consolidated the Company’s dominant position in the region, now totalling 5,140km2, once combined with the existing Nabarlek Project and exploration licence applications (see Figure 5).
The focus of the Company’s exploration activities in the ARUF is on the discovery of additional high-grade Nabarlek-style uranium deposits. UEQ believes that there is outstanding potential to discover more of this style of mineralisation in the region, and has been actively involved with exploring the West Arnhem area in Joint Venture with Cameco Australia Pty Ltd since 2007.
Recently released information regarding Cameco Australia’s Angularli Prospect, located approximately 65km to the north of Nabarlek, displays a similar lithological and structural regime. Buried beneath Kombolgie Sandstone cover sequences, this Nabarlek-style structural quartz breccia zone is strongly mineralised adjacent to the unconformity position with some mineralisation extending into overlying sandstones.
The discovery of significant uranium mineralisation at Angularli greatly expands the area which UEQ considers to have excellent prospectivity for the discovery of further uranium resources (see Figure 5).
The geology, physiography and exploration history of the four Arnhem Minerals licence areas to the north of Nabarlek are very similar. All are located on gently undulating, readily accessible sandy plains, often with thin remnants of weathered Cretaceous sediments or localised outliers of Kombolgie Sandstone on the northern boundary of the McArthur Basin. There are numerous high tenor radiometric anomalies on these tenements that have not been adequately tested.
Underlying basement sequences consist predominantly of Palaeoproterozoic Nimbuwah Complex gneiss, migmatite and granitoids. The exceptions are EL25385 and EL25386, which lie within areas of the Myra Metamorphic terrane and may include domed Archaean sequences similar to those found in the vicinity of Ranger – Jabiluka and adjacent to Caramal.
In light of the recent Angularli discovery and UEQ’s own investigations in the West Arnhem region, all areas will now be re-examined through systematic exploration work. The Company believes that the newly acquired application areas could potentially yield significant uranium resources following a sustained exploration effort.
(1) Source: Northern Territory Geological Survey (NTGS) AGES Conference 2013 presentation by Ian Scrimgeour
(2) Sources: Energy Resources of Australia Limited ASX Announcement – Annual Statement of Reserves and Resources – 30th January 2014
Alligator Energy Limited ASX Announcement – Quarterly Activities Report – 30th April 2014
Lally FH and Bajwah ZU, 2006. Uranium Deposits of the Northern Territory. NTGS Report 20