• Four conducive sources of massive sulphides have been identified at DeSoto’s Spectrum REE and base metals project
  • Targets have high potential for copper and REE mineralisation across a 4.5km strike length
  • Analysis shows target location abuts the gold-mineralised intersection of the Fenton Shear Zone
  • Drilling to commence after EM surveys completed and analysed


Special Report: DeSoto uncovers four prospective copper-REE targets at the Spectrum project using advanced modelling.

DeSoto Resources (ASX:DES) surged late May after inking an agreement to earn-in to the highly prospective Spectrum rare earths (REE) project in the Pine Creek minerals district in the NT.

Historic uranium-focused drilling at Spectrum was completed before REEs were recognised as a valuable critical minerals opportunity.

This drilling, however, pulled up wide zones of high-grade total rare earth oxides (TREO) over a 350m strike, including a highlight 50m @ 1.55% TREO from 245m.


Four targets identified

The multi-metal potential of Spectrum and its surrounds have been highlighted by modelling of the Vesper anomaly, interpreting four conductive sources which may represent massive sulphide bodies.

The Vesper target was identified following initial assessment of the DeSoto-NT Government co-funded SkyTEM airborne electromagnetic survey (AEM) results.

The target area is defined by a 2km-long x 0.5km-wide conductive anomaly that is located 1.5km to the southeast of the Quantum REE-gold discovery.

Desoto Resources (ASX:DES)
The Vesper AEM target, showing four newly modelled conductor plates. Pic supplied: (DES)

The historic copper Mobile Metal Ion (MMI) soil anomaly identified covers the Vesper AEM anomaly and trends north and south along the Fenton Shear Zone (FSZ), connecting both the Spectrum and Vesper prospects, and extends into DES tenure.

Regional geophysical and geological analysis shows that Spectrum is located at the intersection of the gold-mineralised FSZ and a series of trending linears including and parallel to the Hayes Creek Fault (HCF).

Copper, uranium and gold mineralisation is known along the HCF north-east of Spectrum, where the HCF is exposed at surface.

DES says the intersection of the two structures suggests a combination of gold and copper-REE-uranium mineralised systems and may explain why the Quantum REE intercepts also contain economically significant gold values.

The strong positive association of a coincident copper soil and AEM anomaly in a favourable structural setting with known REE-gold is suggestive of a complex base metal + REE-gold mineralised system.


Next steps

A suitable contractor has been identified to acquire fixed-loop ground EM follow-up surveys commencing at the end of this month.

It’s envisaged that the ground geophysical surveys and further local-scale 3D geological modelling will define drill targets to be tested during the 2024 field season.

“Geophysics has been key to focusing drilling in the right areas at Fenton and the 2023 AEM survey results have highlighted the ‘blue sky’ potential of the project well beyond the drilled area,” DES MD Chris Swallow says.

“The company is methodically thinking and working its way through a complex structural system which has the potential to host a significant REE and/or base metal deposit.

“We’re integrating its regional model with targeted geophysics and soil geochemistry to produce high-quality targets to be drill tested in the upcoming 2024 field season.”

It’s also planning a reconnaissance grid-based gravity program in tandem to define structural features in the basement better, that will assist in targeting at both Vesper and Quantum.

A fixed-loop ground EM crew will commence work by the end of June, with ground geophysical surveys to define targets.

Drilling is to commence shortly after completion and analysis of ground EM survey.



This article was developed in collaboration with Desoto 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.