Uranium Equities Limited has identified a significant new exploration target within the Company’s 100%-owned Nabarlek Mineral Lease, directly beneath the historical high-grade Nabarlek Uranium Mine in the world-class Alligator Rivers Uranium Province (ARUP) in the Northern Territory.
The target, which was identified following a recent review of the ore geometry and alteration vectors in the area surrounding the rich deposit, represents a potential offset extension of the high-grade Nabarlek orebody at depth. The offset target sits below a cross-cutting dolerite sill which truncates the deposit.
The offset target represents a new high-priority exploration opportunity for Uranium Equities, which the Company intends to drill test as soon as possible.
Nabarlek Offset Target
Work by Uranium Equities’ technical team during the wet season has focused on characterising alteration patterns associated with the previously-mined high-grade Nabarlek deposit (historical production: 24Mlbs @ 1.84% U3O8) and identifying new drill targets with similar patterns.
In conjunction with this alteration study, the Company has developed a new geological model for the Nabarlek orebody. This model indicates that while the orebody dips to the north-east, it plunges to the north before it is truncated by the Oenpelli Dolerite sill. This suggests that a potential ‘offset’ extension of the Nabarlek orebody may be located to the north beneath the barren dolerite sill (Figure 1).
The concept is supported by limited historical drilling beneath the dolerite sill which had targeted down-dip extensions of the orebody, but not the modelled down-plunge extensions of the system below the sill. Analysis of the spectral and geochemical signatures of these deeper holes has identified alteration chemistry and mineralogy analogous to the Nabarlek signature, suggesting that these holes intersected an alteration halo adjacent to the untested offset target located north of the historical drilling (Figure 2). This provides a clear vector for the Company to target offset mineralisation beneath the dolerite.
The Company considers this structural target to be analogous to the Ranger 3 Deeps mineralisation discovered by ERA in 2009, where the principal structure that hosts mineralisation – a reverse fault with associated breccia zones, alteration and mineralisation – extends to over 500m vertical depth (Figure 3).
Drawing on this analogy, the interpreted offset target has the potential to extend the high-grade mineralisation at Nabarlek by a further 400 vertical metres down-plunge.
The alteration study comprised the collection of new analytical data and a reassessment of existing data, including short-wave infrared (SWIR) spectral and multi-element geochemical data, from historical and company drilling. This included analysis of a number of historical holes which had been drilled under the old pit at Nabarlek, using the Northern Territory Government’s “HyLogger” analyser.
The study builds on knowledge of characteristic signatures of uranium and other sediment hosted metal deposits globally that the Company’s geologists, working with recognised industry experts, have extensive knowledge of and believe to be proprietary to the Company.
The re-assay and mineral spectral analysis defined a distinctive alteration pattern surrounding Nabarlek within Cahill Formation equivalents which are the host rocks to the Nabarlek deposit (Figure 4). These associations include:
- Vanadium enrichment and lithium anomalism strongly correlated with the uranium lodes; and
- Molybdenum anomalism proximal to ore.
Short Wave Infra-Red (SWIR) Spectral Signature
- Short wavelength (magnesium-rich) chlorite halo proximal to ore; and
- A core of aluminium-poor white mica (phengite) proximal to ore within a broad zone of muscovite representing calcium-sodium (Ca-Na) depletion.
Click here to view Appendix 1 Nabarlek Drilling JORC Criteria