Best known as a producer of tin and gold, Tasmania is now in the global eye as an exciting new destination for the hunt for rare earths after a number of significant recent discoveries.
Importantly, the exciting new discoveries have not only been very large, they have also been found to contain some of most sought-after and valuable rare earth elements (REEs).f
The exciting potential of the new discoveries has led to a land rush as explorers move quick to grab a piece of the rich action.
There has been a noticeable increase in tenement applications on the island. These have included the search for rare earths in their planned activity descriptions, while already established miners and explorers are having historic drill cores re-tested for traces of rare earths.
Leading the way in creating this new excitement is Abx Group, which has obtained some dramatic drilling results this year.
ABx Group Limited’s (ASX: ABX) latest assay results have confirmed a 6.5km mineralized channel connecting the company’s Deep Leads and Rubble Mound rare earth discoveries, located in northern Tasmania.
The clay-hosted rare earth elements (REE) occur within a shallow channel structure that increases the prospect size by 27% to 5.1km2 and demonstrates the potential for the mineralized zone to deliver thick intersections as well as expand significantly along strike.
The combined prospective area to be drill tested has increased to more than 30km2.
“Our latest results represent a milestone moment in our development of the rare earth channel at Deep Leads and Rubble Mound. The extensive channel structure has connected and combined the two discoveries into a single deposit and, excitingly, the mineralization has also been shown to return results which are thick – exceeding 20m thickness – and near surface,” said Dr Mark Cooksey, ABx Group’s managing director and CEO.
“These are only first-pass results, with this emerging discovery possessing clear potential to significantly expand the mineralized corridor between the connected areas as well as along strike.
“The assays confirm the rare earth oxides encountered are rich in the four high-value ‘permanent magnet’ elements that are critical for advanced technologies, such as electric vehicles, smart phones, and wind turbines.
“Furthermore, not all clay-hosted rare earths are created equal. Only those clay deposits formed by ionic adsorption of REE metals onto clays (IAC REE) achieve high extraction rates at low cost and are the most sought-after deposits.
“ABx Group has confirmed Deep Leads possesses these ionic adsorption clays and has successfully delivered extraction rates of 50% to 75% of contained REE using benign, low-cost processing techniques. ABx is the first to discover true IAC REE in Tasmania,” he added.
The company says assay results confirm the adjoining mineralization contains “excellent grades”, with holes such as RM217 returning a maximum of 2,511ppm of total rare earth oxide (TREO). This hole has also proven that the channel can host thicker intercepts, in this case to a depth of over 20m. Further work will be required to assess the size and depth potential of this connected area.
To date, rare earths encountered have typically been concentrated in buried channel structures of six to 12m depth. However, the latest results demonstrate the region’s capacity to host even shallower mineralization, with RM219 recording a 1m assay grading 1,884ppm TREO at surface.
These results will feed into a maiden JORC Resource Estimation, which is already underway.
The receipt of the company’s latest assay results has increased ABx’s confidence in its geological interpretation and has informed targeting work for the current drilling programme, which commenced in October 2022.
Exciting REE adventure for Venture
Elsewhere, Venture Minerals Limited (ASX: VMS) – perhaps best known as a tin miner – has discovered shallow clay hosted REE mineralization after undertaking a re-assaying exercise.
The new assay results identified valuable REEs immediately adjacent to existing tin zones within the Mount Lindsay Project’s tin resources.
The discovery followed the re-assaying of a preliminary selection of 39 remnant pulp samples from clay zones in the hanging wall of the Reward Tin Deposit (0.5 Mt @ 0.9% Tin).
TREO results included:
- RW021 16.4m @ 1,029ppm TREO from 31.9m, including 1.6m @ 2,549ppm TREO & 0.19% Sn from 46.7m
- RW034 7.5m @ 1,287ppm TREO from 2m, including 3.0m @ 2,055ppm TREO from 2.0m
- RW027 19.3m @ 725ppm TREO from 64.2m, including 2.8m @ 2,486ppm TREO from 65.7m
- RW004 8.0m @ 729ppm TREO from 75m, including 2.0m @ 1,770ppm TREO from 81m
Venture says the preliminary re-assaying of Reward pulps for REEs represents only <5% of the historic Reward assay sample database and all but two samples returned REE anomalous or mineralized materials.
In view of these highly encouraging results the company is now initiating a broader and systematic programme re-assaying of historic drill core from the Reward and Livingstone tin deposits for clay hosted REE mineralization.
The company has already prioritized a drill rig to follow-up the newly identified REE mineralization at the Reward Tin Deposit to further define this REE opportunity, and the first hole is currently in progress.
Venture believes the REE zone could potentially be mined concurrently with the tin thereby increasing the value proposition of mining at Reward. At this stage, the identified REE mineralization is open in all directions.
New studies
The state’s rare earths potential will also be part of a study being undertaken by the University of Tasmania.
The University’s Centre for Ore Deposit and Earth Sciences (CODES) recently received an A$3.5M federal government grant to fund a novel three-year collaborative partnership between researchers from CODES, education researchers in the College of Arts, Law and Education and the Tasmanian minerals industry.
The partnership will enable UTAS to work with industry and government to investigate environmentally sustainable critical metals and improve educational outcomes and regional job opportunities for communities in Tasmania’s west coast region.
Nine Tasmanian industry partners will participate in the project, along with the Tasmanian Minerals, Manufacturing and Energy Council and Mineral Resources Tasmania. The research project will be known as “environmentally sustainable production of critical metals”.
The collaboration will also include partner academic institutions – the University of Queensland and the Université de Liège (Belgium). The nine industry partners include ABx Group and its Deep Leads exploration project.
