Brazil-focused explorer BBX Minerals has used ternary radiometric imaging and the Th/U factor to define 14 high-priority targets across 19.4 square kilometres of the Ema and Ema East ionic rare earths (iREE) leases in Brazil.
Th/U is often employed in identifying preserved regolith profiles which have developed on granites and felsic rocks.
The new targets have developed on top of rhyolite and are believed to be similar to deposits in the Guangxi region in southwest China.
An elevated radiometric Th/K signature was also observed, indicating leaching of potassium from the regolith.
It is widely known to be an exploration indicator for targeting preserved regolith.
Expanding potential
Chief executive officer Andre J Douchane said the new targets expand the potential area for high-grade ionic rare earths across the bulk of the 188.73sqkm of Ema and Ema East.
“The discovery of rare earth elements in this region of Brazil appears to have taken on a life of its own… it is an incredibly exciting development and seems to be much larger than our initial expectations,” he said.
“The timing is perfect as our geological team can now fully focus on this new discovery.”
He said ongoing exploration would involve deeper auger drilling and a comprehensive topographic drone survey to delineate regions of undulating topography with the potential for significant thicknesses of the preserved enriched horizon.
TREO enrichment
At Ema, zones exhibiting TREO (total rare earth oxides) enrichment commence at depths of up to 11 metres.
In similar Chinese mineralisation within the Indosinian felsic volcanic rocks of Guangxi, the enrichment begins at 1m, with the highest values occurring around 3m.
The distinction has been attributed to variations in the weathering regime, characterised as sub-tropical in southwest China and tropical in the Amazon.
Of all the iREE projects in Brazil, Ema and Ema East are considered to be unique in that they share identical characteristics to similar iREE deposits found in southwest China.
Mr Douchane said BBX would continue to progress its iREE projects at Ema, Ema East and Apui which are characterised by relatively fast drilling and development processes, low capital expenditure and operating costs, straightforward metallurgical processes and the production of high-value REE offtake products.
