The Nabarlek Project comprises the 100% owned Nabarlek mining lease (MNL 962) and the 427 km2 West Arnhem Joint Venture (Uranium Equities earning 100%) and is located approximately 270 km east of Darwin, Northern Territory, and less than 60 km from the world-class Ranger and Jabiluka uranium deposits.
Nabarlek Project - key tenements and exploration targets surrounding the Nabarlek mine
Discovered in 1970, Nabarlek was Australia's highest-grade uranium mine, producing 24.4 million lbs of U3O8 at a grade of 1.84% U3O8. It was mined by Queensland Mines Ltd. between 1979 and 1988. Mining ceased when the resource was truncated by a dolerite sill. In 2008 Uranium Equities acquired Queensland Mines Pty Ltd, which owned the Nabarlek mining lease, as part of its consolidation of tenements in the district.
Geology and Prospectivity
Uranium Equities is targeting high grade unconformity-related uranium deposits, similar to that of the historic Nabarlek mine. There are numerous uranium occurrences outside of the Nabarlek mine; however, the area is under-explored and with limited effectiveness due to transported overburden or a buried basal unconformity contact. Accordingly, geophysics has important role to play in focusing exploration in priority areas.
Uranium Equities completed a technical review in early 2016 across the project area using integrated geology-geophysics-geochemical datasets. The review identified prospective areas with comparatively little historical exploration and a field activities later in the year addressed the lack of effective exploration data in key target areas. In particular, Uranium Equities is applying Gpx surveys (gravity, magnetics, EM) to target areas. Gpx surveys have been driving recent exploration successes in ARUP and Athabasca Basins.
Gravity survey over West Arnhem Joint venture ground in 2016
Key target areas within the Nabarlek Project include:
Namarrkon is located approximately 12 km SW of the Nabarlek Mining Lease.
Field mapping in 2016 identified the target along the southern extension of the Quarry Fault, which hosts the U40 prospect 10 km to the north. A follow-up radon-in-soil survey identified a 2km long radon-in-soil anomaly (at 4x background Rn) with peak values up to 44x background Rn concentrations that directly overlies the interpreted structure. Further encouragement came following a surface scintillometer survey over the same radon-in-soil survey stations showing low surface radioactivity over the radon-in-soil anomaly, which is interpreted to show that the radon – and therefore uranium mineralization – is sourced at depth below transported channel sediments.
Radon-in-soils anomaly at Namarrkon
Surface scintillometer readings over the radon-in-soils anomaly (red line)
Uranium Equities is encouraged by results to date and have made Namarrkon a high-priority target for 2017. The company is designing a RC drill program (approx. 1,500 metres) to test the basal sandstone units for the source of the radon anomalism.
Nabarlek is an unconformity-related uranium deposit. Mining ceased in the 1980s due to mineralization being truncated by a dolerite sill (the Oenpelli Dolerite).
Previous operators did not adequately test for extensions of mineralization beneath this sill. This target is referred to as the Nabarlek Offset target. In 2015, Uranium Equities drilled two lines of holes to test the prospectivity of the target.
Uranium Equities’s drilling and historic drilling, including the older hole NAD083, recorded structure, alternation zones and anomalous amounts of Mo, Li, Cu, Ag with trace U. The alteration zones and pathfinder geochemistry are consistent with proximity to uranium mineralisation, thus supporting the Nabarlek offset model beneath the Oenpelli Dolerite.
Modelled alteration halo
Uranium Equities’s priority target is an untested 2.1km long structure beneath Oenpelli Dolerite.
The GC-11 target is located to the south-west of the Nabarlek Mining Lease.
The target has been generated from the confluence of several geochemical, geological and geophysical techniques – defined as gravity lows and intersecting fault structures determined through a combination of gravity and EM, favourable orientation of basement structures is NNW-NW which is subparallel to the Nabarlek fault, previous drilling indicated characteristic alteration and uranium mineralisation suggest drilling intersected the margin of a U-related alteration halo.
GC-11 Target at depth
Follow-up geophysics has been completed to define trend of mineralising structure(s) and RC drilling is planned at GC-11.
The SMLB prospect is located immediately to the north of the Nabarlek Mining Lease.
It covers an area of mostly poorly explored Cahill Formation schists intruded by Oenpelli Dolerite within an extensive area of transported sands, and an eastern area comprising a prominent range of outcropping Kombolgie Sandstone. Previous RAB and diamond drilling has been largely ineffective due to poor targeting and the rugged terrain has restricted access for drill testing.
A ground gravity survey completed by Uranium Equities has defined a set of subparallel interpreted structures mostly aligned along a NW orientation. Uranium Equities believes that these target areas require follow-up with effective exploration techniques and it is proposed to field check the target and determine the appropriate next step in testing these targets.
SMLB ground gravity survey (1VD) showing interpreted structures and priority target area
The East QFZ survey is located east of Nabarlek and directly adjacent to the Quarry Fault Zone survey completed in 2011, in an area which has received only limited exploration focus. The recently completed gravity survey by Uranium Equities has identified a network of interpreted structural lineaments and areas of extensive near surface Oenpelli Dolerite sills/dykes.
The target areas outlined on the ground gravity survey represent prominent gravity low trends. Other prominent gravity lows occur along subparallel structures, some of which airborne radiometric anomalies and coincident soil anomalism.
East QFZ ground gravity survey showing interpreted structures, Oenpelli Dolerite, and priority target areas (11-19).
The Company will soon prioritise areas for exploration follow-up.
In latter half of 2007, Uranium Equities acquired a 40% interest in the Nabarlek package of tenements from Cameco by spending A$6 million (excluding the Nabarlek Mining lease which is owned 100% by Uranium Equities).
A further spend of A$2 million by 31 December 2017 will increase the Company’s ownership to 100%. As of 31st December 2016 the Company has incurred expenditure of A$1.91 million, with a further $0.09 million remaining.
Cameco have clawback rights for 51% of any deposit exceeding 50 million lbs of U3O8 within the West Arnhem JV area.