top of page

Mount Ridley hails “prodigious” rare earths in Esperance

Updated: Apr 19

Mount Ridley Mines is hunting rare earths to impact the electric vehicle industry. Credit: File

Mount Ridley Mines has revealed some of its best rare earths results to date from its project near Esperance in Western Australia after first-pass drilling threw up a suite of intercepts, including a headline hit of 15m at 2919 parts per million total rare earth oxides (TREO) from 18m.

The program of 36 vertical air-core (AC) holes endured through a total of 988m at two targets on the company’s easternmost exploration licence, about 90km north-east of Esperance. The two targets – known as Jimmie and Lance – lie on about the same northing some 2km apart and were drilled on two separate bush tracks, with holes spaced at 400m intervals.

Management believes the results put the company in the frame to become a credible global alternative supplier for clay-hosted rare earths.

The best intercept also contains 20 per cent magnet rare earth oxides (MREO), while the next best value of 2774ppm TREO came in a 12m intercept from 6m and contains 19 per cent MREO.

The results also featured 30m at 2026ppm TREO from 9m with 20 per cent magnet rare earths (MREO).

MREO refers to the sum of the elements neodymium, praseodymium, dysprosium and terbium, which are important constituents of permanent magnets considered vital for electric vehicles (EVs) and other equipment demanded by the global decarbonisation program.

The Jimmie target was tested with 19 holes along a track running in a north-east/south-west direction, while the Lance target was drilled with 17 holes along a track oriented north-west/south-east. The results are remarkable for their relative uniformity and consistency of depth from surface, intercept thickness and grades within broad ranges.

Moreover, they represent a rewarding result from the company’s first-pass drilling in a new geological terrane – the younger Nornalup Zone granites. It had not tested it previously, but the area has been explored by OD6 Metals, which is exploring a vast tract of ground nearby for rare earths potential.

The company explains that all its previous drilling in the project area had focussed on the main block of licences where the clays lie on older terrane comprising Biranup Zone granites and Grass Patch mafic rocks.

The fact that drilling in untested areas is still locating new, high-grade zones underlines the prodigious extent of clay-hosted rare earth mineralisation at the Mount Ridley Project. It is noteworthy that almost all the world’s critical heavy rare earths, in particular terbium and dysprosium, are sourced from clay deposits in China and Myanmar. As the Mount Ridley clay-hosted REE project advances, the potential for it to become an alternative source of these critical heavy rare earths is becoming more apparent. Mount Ridley Mines chairman Peter Christie

A quick scan of the hole collars and drill logs shows that the shallowest drillhole was just 4m, while the deepest hole ran to 54m. The surface terrain is uniformly flat at about 191m above sea level and all holes were drilled to refusal – the point when they encounter rock that cannot be drilled by the method in use.

From the data, the basement mapped out by the bottom-of-drilling is undulating with rare earths-bearing clays in deeper depressions, which are possibly scours or channels, or simply variations in the natural weathered surface of the local granites prior to their burial under later sediments.

Mount Ridley holds 85 per cent of the project licence in a joint venture with Odette Geoscience, which has the remaining 15 per cent. The operation lies about 12km east of its otherwise contiguous suite of licences and together, they make up its namesake Mount Ridley rare earths metals exploration project.

The program has turned out to be literally a journey of discovery for Mount Ridley and not only extends its area of exploration by an order of magnitude, but has yielded a shallow, accessible and potentially high-grade rare earths resource close to the excellent Esperance port infrastructure for shipping.

Is your ASX-listed company doing something interesting? Contact:


Commenting has been turned off.
bottom of page