• High-grade intercepts at the U40 prospect have identified an extensive uranium-bearing fault zone, the U40 Fault
  • RC drilling at Nabarlek South has encountered uranium at the unconformity between the Kombolgie Sandstone and the regionally significant Cahill Formation
  • Current drilling campaign to be expanded in light of these new results

Uranium play DevEx Resources will expand ongoing drilling around its historical Nabarlek uranium mine in the NT after reporting significant new results including grades of up to 1.68% eU3O8 along a main uranium-bearing fault zone.

DevEx is currently drilling along two major uranium-bearing fault zones, the Nabarlek Fault (the Nabarlek South and Nabarlek North Prospects) and the U40 Fault (the U40 and U42 Prospects).

Both fault zones are known to host high-grade uranium mineralisation, including the historical Nabarlek mine, considered Australia’s highest-grade uranium mine with past production of 24Mlbs @ 1.84% U3O8.

New step-out drilling to the north and south of previous high-grade intercepts at the U40 prospect has identified the uranium-bearing ‘U40 Fault’, returning new uranium equivalent intercepts including:

  • 33.7m @ 0.12% (1,200ppm) eU3O8 from 59m – which is open to the south;
  • 4.9m @ 0.38% (3,800ppm) eU3O8 from 42m, including 0.5m @ 1.68% (16,800ppm) eU3O8 and 0.7m @ 0.58% (5,800ppm) eU3O8; and
  • 23.7m @ 0.19% (1,900ppm) eU3O8 from 60m, including 0.4m @ 1.07% (10,700ppm) eU3O8; 0.2m @ 0.52% (5,200ppm) eU3O8.

DevEx Resources (ASX:DEV) says the uranium mineralisation is open to the south and interpreted to continue for several kilometres, linking up with intercepts discovered last year at the U42 prospect.

At Nabarlek South, RC drilling has discovered uranium mineralisation for the first time at the unconformity between the Kombolgie Sandstone and the regionally important Cahill Formation, with significant results including:

  • 2m @ 0.77% (7,700ppm) U3O8 and 0.6g/t Au from 132m; and
  • 3.5m @ 0.18% (1,800ppm) eU3O8 from 148m.

DevEx says both holes show significant bed-rock alteration at the unconformity, consistent with other major uranium deposits in the region, including those at the Nabarlek and world-class Ranger uranium mine, which produced 300Mlbs at 0.23% U3O8.

“[We] believe that these new intercepts are indicative of a nearby uranium-bearing structure – possibly the southern continuation of the Nabarlek Fault,” the company says.

DevEx Resources
An illustration of the extension of the U40 fault zone. Pic supplied: (DEV).

DevEx MD Brendan Bradley says the company’s 2023 exploration campaign “is off to a great start, with significant uranium intercepts returned in multiple holes at several prospects”.

“The focus of step-out and in-fill drilling is along two key corridors – one along trend from the historic Nabarlek Mine, the other to the north-east along the U40-U42 trend,” Bradley says.

“Apart from the growing footprint and scale of the mineralisation, we are also excited to see new high-grade mineralisation being encountered at the unconformity between Kombolgie Sandstone and the regionally significant Cahill Formation – a classic geological host to some of the largest deposits in the district such as the world-class Ranger uranium mine.

“These exciting developments have prompted us to expand and extend the current drilling program.”

A prolific uranium province

Nabarlek is situated in the NT’s Alligator Rivers Uranium Province (ARUP), where over ~500 million pounds (Mlb) of uranium has been either mined or defined in Mineral Resources, including the historical Nabarlek uranium mine (within DevEx’s tenements) which produced 24Mlbs at an impressive grade of 1.84% U3O8.

The province’s significant uranium endowment is exemplified by the numerous-world class uranium deposits which have been discovered, including the Ranger uranium mine (which produced 269Mlbs U3O8), and the Jabiluka uranium resource (307Mlbs @ 0.55% U3O8). New mineral resource expansions at Deep Yellow’s Angulari Project (32.9Mlbs @ 1.09% U3O8) continue to show what the province can deliver.

Uranium is on its way back as a clean source of baseload energy required for the global transition to electric vehicles and other battery storage devices, as reflected in steady increases in the uranium spot price over the past year.

DevEx says the compelling investment case for uranium provides a strong backdrop to its uranium exploration campaign at Nabarlek, which is one of the few active high-grade uranium exploration opportunities on the ASX.

Next steps

DevEx says an expanded in-fill and step-out RC drilling campaign is now underway to follow up on the recent hits surrounding the old mine alongside expanding drilling between U40 and U42 Prospects.

After gaining approvals from the NT Government, the company will then also drill test the Nabarlek Fault to the northwest of the historic mine site, as ground surveys and reviews show that a significant portion of the fault remains untested.



This article was developed in collaboration with DevEx Resources, a Stockhead advertiser at the time of publishing.


This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.