Si6 nabs more Brazilian turf for rare earths hunt

Si6 Metals has expanded its Brazilian footprint, snatching 300 square kilometres of new ground prospective for rare earths in the Brazilian State of Minas Gerais.

The newly-acquired turf, dubbed the Pimenta project, sits in the north-east of the State and has thrown up some head-turning radiometric anomalies over 26km of untested strike. It adds further ground to the Brazilian joint venture (JV) it shares with local exploration experts Foxfire Metals.

Si6 says the ground already shows significant thorium anomalies, indicating that high rare earths prospectivity exists in the weathered profile within  granitic source rock. Thorium is known as a rare earths-rich accessory mineral and is a useful indicator for areas of high prospectivity.

The company says the granites are of the magnetite-biotite variety with significant allanite content – a group of minerals that are known to contain rare earths. It says allanite-hosted rare earths deposits are well known globally as being typically large and for providing low-cost mining of ore with a high content of valuable magnetic rare earths.

Notably, American Rare Earths is sitting on 1.42 billion tonnes of measured and indicated resources grading 3296 parts per million total rare earth oxides (TREO) at Halleck Creek – an allanite-hosted deposit in Wyoming.  That mammoth deposit has encouragingly-high magnetic rare earths content sitting at 27.1 per cent.

At Pimenta, Si6 says it sees an area of elevated thorium content at more than 500ppm in the southern portion of its acreage. Additionally, it says the thorium-potassium ratio map, used to indicate preserved weathering profiles, shows a zone within the thorium anomaly where weathering may have concentrated rare earths into prospects begging to see the drill bit.

And drilling is exactly what Si6 is planning on doing at Pimenta, with a future exploration program being developed to test weathering profiles once all licence applications are granted. Three of the company’s 16 applications for new ground have already been given the go-ahead and management says it expects approval for the remaining 13 to follow in due course.

The ground is being acquired by the company’s fully-owned subsidiary Brazilian Mining Ventures as part of the Foxfire JV. The two companies held an even 50 per cent share for past ventures, but Si6 recently negotiated to elevate to a 70 per cent slice for all future acquisitions – including the latest ground grab.

The acquisition follows drilling results released to the market earlier this week where Si6 revealed an eye-watering assay of 5475ppm TREO from surface, with 36 per cent magnetic rare earth oxides. That hit was from the company’s Caldera project in the south of Minas Gerais and came from the first batch of drillholes in the area.

It was a promising start and there are more assays pending.

The next few months are shaping up to be a busy period for Si6 in Brazil as it chases more rare earths, now with an expanded footprint.

Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au