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Codrus hails first-hole rare earths find in Karloning clay

Updated: May 6

RC drilling at the Karloning rare earths project in Western Australia. Credit: File

Codrus Minerals has discovered high-grade clay-hosted rare earths in the first drill hole at its Karloning project, about half-way between Perth and Kalgoorlie in Western Australia.

The company says the find adds extra value to the hard-rock hopes it had for Karloning when it entered a farm-in and joint venture agreement with Talgomine Minerals to acquire a 90 per cent interest in the project’s 3km-by-1.5km exploration licence in November last year.

Codrus also pegged a further exploration licence adjoining the south-west side of Karloning – which is centred around the 1.5km-long Karloning pegmatite. It takes in the strike extension in the same direction.

Karloning is a substantial pegmatite rare earths prospect where Codrus has just completed its first 13 RC drill holes. Observations during drilling led to rushing the first 40m of the first hole to the assay laboratory and grades up to 4764 parts per million total rare earths and yttrium oxides (TREYO) were returned in 4m from 12m downhole. A 12m hit at 2679ppm TREYO was recorded from 8m downhole.

Management believes the results significantly upgrade the Karloning project because it adds clay-hosted rare earths to its known pegmatite hard-rock mineralisation. It is now assessing the geological data and will refine the mineralisation and geological context when all assays have been received.

Codrus views Karloning as an opportunity to diversify into critical minerals and build on its copper and gold assets in a commodity sector it says has outstanding fundamentals and a strong growth outlook. The drilling program was aimed at confirming the project’s credentials as a rare earths sector growth and diversification opportunity.

The company last month completed its 1906m of RC drilling. All samples are at the laboratory, but only the initial 40m intercept from the first hole has been assayed.

The RC holes ranged in depth from 100m to 244m. Codrus says 12 holes tested a TREYO soil anomaly extending south-west from the Karloning pegmatite quarry, with drill spacing of about 80m and lines 100m apart.

One hole was drilled to test the south-west extension of the pegmatite observed in the quarry. It is outside the quarry pit immediately adjacent to the south-west side.

The first hole was drilled to 154m, with clay and saprolite seen in the first 20m, before saprolite declined in the 21m to 40m zone. TREYO mineralisation was confirmed in the clay and saprolite zone, with lower-grade mineralisation assayed in the transition to fresh rock.

Assays showed 32m grading 1433ppm TREYO from 8m with the higher-grade interval of 12m at 2679ppm TREYO from 8m, including the 4m going 4764 ppm TREYO from 12m.

This is a very exciting result from our first ever drill hole at Karloning, confirming the presence of shallow clay-hosted rare earths mineralisation in addition to the hard rock hosted REE mineralisation that the project was originally acquired for. This provides Codrus with the opportunity to pursue rare earths discoveries within two separate geological units – both the near-surface clay horizon and the pegmatites. Codrus Minerals managing director Shannan Bamforth

The project area geology is comprised of biotite granite and adamellite, with the large Karloning quartz-microcline pegmatite intruding the host rock. Mapping by the Geological Survey of Western Australia shows a strike extent of 1.5km for the Karloning pegmatite.

Codrus believes there is a potential significant extension to the pegmatite beneath cover and for multiple pegmatite horizons to be discovered within the project area. It says opportunity may exist to identify broader zones of lower-grade rare earths mineralisation in the widespread alkaline granite.

Granite with pegmatite outcrops in the Karloning quarry to north-east of the drilling area. The company’s drilling targeted areas interpreted to potentially contain clay and saprolite zones in weathered granite with pegmatite veins.

In related news today, Caprice Resources announced the identification of an outcropping pegmatite with a 1km strike length in its tenement, which immediately adjoins Codrus to the south-west. Caprice reported a significant rare earths anomaly with rock chips and soil samples returning up to 3761ppm TREO.

The discovery adds further weight to Codrus’s interpretation that the rare earths-rich Karloning pegmatite continues through its ground south-west of the Karloning pegmatite quarry and that other pegmatites probably exist in the host granite rock, which Caprice appears to have demonstrated.

Codrus undertook additional soil sampling while on-site for its drilling program. The company will plan follow-up drilling after consideration of its assay results, which are yet to be received.

While no scandium assays have been received, similar deposits such as Asra Minerals’ yttria deposit near Leonora have revealed scandium-rich zones.

Codrus has now generated proof of TREYO mineralisation within both its hard-rock pegmatite and clay-saprolite zone, helping it take a major step forward in its hunt for diversification into the rare earths space. The geological interpretation and assay results for the drilling will be the first evidence of the scale of mineralisation at Karloning and it is definitely one to watch.

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