Heavy Rare Earths has started exploration at its Duke project in the Northern Territory to test for potentially lucrative unconformity-type REE mineralisation.

Notably, this is the same type of mineralisation found at the third-party Browns Range project in Western Australia, which is known for its high heavy REE content and is progressing towards production.

Heavy Rare Earths (ASX:HRE) has now commenced a first pass soil survey over an extensive area of rare earth enrichment and anomalous radiometric thorium at the project where historical drilling and rock chips returned assays of up to 732 parts per million total rare earths (TREE).

Large parts of the target area are also overlain by a clay-rich regolith up to 20m thick, which presents the potential for ionic adsorption clay-hosted mineralisation to be present.


Duke project’s infrastructure

Duke comprises two adjacent granted exploration licences EL33101 and EL33194 which cover 255km2 on the Phillip Creek pastoral lease about 50km northwest of Tennant Creek and 25km west of the Stuart Highway.

Additionally, both the Alice Springs to Darwin railway and Amadeus natural gas pipeline cross the central part of the project area.

Previous exploration was focused on trying to find ironstone-hosted copper-gold-bismuth and IOCG deposits.

During a reconnaissance visit carried out in April 2023 to assess access, the company took the opportunity to investigate prominent thorium anomalies from a previous explorer’s airborne magnetic/radiometric survey over the project area using portable XRF and a gamma-ray spectrometer.

The pXRF analysis confirmed the presence of elevated rare earths at outcrop (silcrete and quartz veining) with values of up to 0.21% (2100 ppm) TREE recorded.

Additionally, core from a diamond hole drilled in 2009 to test a uranium anomaly from the same airborne survey was sampled by HRE, returning assays of up to 732 ppm TREE in the Warrego Granite.

HRE’s reconnaissance work therefore confirms an extensive zone of rare earth enrichment in hydrothermal quartz veining, surficial silcrete, and in the Warrego Granite.

The company’s first-pass systematic exploration involves acquiring soil samples over a grid measuring 23km2 to cover the area of thorium anomalism, a large zone of quartz veining and a sizeable but discrete copper-gold-bismuth soil anomaly that was identified in previous exploration but never drilled.

In addition to the soil survey, the effectiveness of stream sediment sampling will be assessed to explore the more difficult-to-access northern, western and eastern portions of the project area.



This article was developed in collaboration with Heavy Rare Earths, 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.