St George Mining has delivered what it says are “groundbreaking” clay-hosted rare earths grading up to a huge 5125 parts per million total rare earth oxides (TREO) in the company’s first drilling foray into its Destiny project in Western Australia’s Goldfields region.
Highlights from the company’s maiden 61-hole air-core (AC) program at Destiny include 30m at 1885ppm TREO and 399ppm magnetic rare earth oxides (MREO) from 20m, including the 2m section at a massive 5125ppm TREO and a 6m chunk at 3578ppm TREO. The thickest hit was 42m at 1832ppm TREO and 351ppm MREO from 12m.
St George says the rare earths enrichment is now confirmed by drilling through a 7km-long section of strike and remains open in all directions. Less than 10 per cent of the target area has been tested by the drillbit to date and the company believes the mineralised geology may extend for up to 70km.
Management says the valuable MREOs – which are critical for their role in making the high-strength permanent magnets used in electric motors – comprise an average of 19 per cent of the TREO.
The less common, but highly-valuable heavy rare earth oxides (HREO) make up an average of 17 per cent of the TREO and are a critical element of the orebody makeup, as some elements within the group are facing shortages as global demand outpaces supply.
St George Mining executive chairman John Prineas said: “The high grades returned in the assays are very exciting. Together with the scale of the prospective geology – which may extend for more than 70km – the potential of the Project is impressive. Importantly, the assays show a high proportion of sought-after magnetic rare earths – a feature that could be a huge value driver for the Project.”
Prineas said management was keen to resume drilling at Destiny in the new year in a bid to unlock its rare earths potential. He said the project complemented the company’s lithium and nickel assets.
St George is targeting the rare earths-enriched clays at Destiny after Mincor Resources tripped over them in 2010 while drilling for nickel in the area, which it named Woolgangie. Mincor’s reverse-circulation (RC) assays showed 24m at 649ppm cerium-lanthanum-yttrium from 8m in one hole and 36m at 556ppm from 20m and 84m at 386ppm from 96m in the other.
Mincor’s rotary air-blast (RAB) holes returned assays as high as 32m at 236ppm cerium-lanthanum-yttrium from 24m, 20m at 567ppm from 86m, 16m at 382ppm from 26m and 18m at 244ppm from 28m. Significantly, the holes were not assayed for MREO or HREO, leaving plenty of potential on the table.
The Destiny project covers an area of 3350 square kilometres, encompassing more than 90km of the Ida Shear Zone – a 500km-long regional lineament trending north-south and separating the Eastern Goldfields Terrane from the older Southern Cross Terrane.
Ida is suspected of controlling hard-rock lithium mineralisation in the area. including Liontown Resources’ Kathleen Valley lithium deposit that boasts 156 million tonnes at 1.4 per cent lithium oxide and Delta Lithium’s Mt Ida deposit, which has 14.6 million tonnes grading 1.2 per cent lithium oxide.
St George is looking for lithium at Destiny, too, with a soil and rock-chip sampling program underway in virgin ground. Along strike of the Ida Shear and adjacent to Destiny’s tenements, Neometals announced last month that holes drilled at its Spargos project showed spodumene-bearing pegmatites – although assays are yet to be returned.
The maiden set of rare earths assays from St George’s first look at Destiny only represent a 30-sq-km patch of its ground holding and cover about 7km of the Ida Shear at a wide spacing of 500m. The company will no doubt be looking forward to infill drilling near the recent hit, in addition to walking the rigs out to see what else Ida has to offer.
St George says it will be back drilling at Destiny early next year and will kick off metallurgical testing on selective drill samples to determine the characteristics of the mineralisation, including the extractability. The lithium prospectivity will also be tested with the drillbit following initial target-generation to be established through fieldwork.
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By Andrew Duffy
