Gold Mountain is set to kick-off rare earths exploration work this month at its Down Under project in Brazil, along strike from and flanking ground hosting Brazilian Rare Earths’ massive 510.3-million-tonne resource.
Management says it will be drilling in the next six months, guided by a local geologic consultant, who will assess radiometric and magnetic data in conjunction with satellite imagery to define prospective areas begging to see the drill bit.
The company says its first exploration priority will be “free-digging” ionic-adsorption clay (IAC) rare earths mineralisation that exists within the first 30m to 40m of ground. It will be followed by a close look at prospectivity within the hard-rock interval beneath, where it hopes mafic-ultramafic bodies and shear zones may hold exceptionally high rare earths grades.
Gold Mountain’s geological model is that the structures in the region, believed to be dominated by strike-slip faulting, were likely conduits for intrusion of hydrothermal rare earths mineralisation and mafic-ultramafic rare earths-mineralised bodies. Management believes the intrusive bodies are the source of clay-hosted rare earths deposits derived by weathering of the primary host rocks. It says the high-grade, hard rock style of mineralisation is known in a strike length exceeding 80km in tenements adjacent to and along strike from its ground at more than 30 locations.
Gold Mountain’s main chunk of ground is less than 40km – and as close as 5km – south of seven defined rare earths deposits in Brazilian Rare Earths’ tenure that comprises its Rocha da Rocha project boasting grades as high as 40 per cent total rare earth oxides (TREO) – that’s a coffee-spitting 400,000 parts per million.
Brazilian Rare Earths is a Gina Rinehart-backed, New South Wales-based explorer and has revealed a hulking inferred resource of 510.3 million tonnes grading 1513ppm TREO at the project.
Down Under is in the state of Bahia in north-east Brazil and Gold Mountain’s main tenement groups sit about 190km along sealed roads from the port of Salvador on the east coast. The area has seen a rush of companies into the area of late hunting for rare earths and lithium, many of those hailing from Australia – leading to the project’s patriotic name.
While Gold Mountain prepares to take a look at Down Under, work at the company’s undrilled Custodia hard-rock lithium project, also in north-east Brazil, has produced some eyebrow-raising results.
Stream sampling at Custodia has identified 15 new areas with lithium concentrations exceeding background levels and only two of the areas have seen overlapping soil sampling programs to date. The company says it will be back on the ground shortly to conduct an extensive follow-up soils program before getting a drill bit in the ground as soon as possible.
Management says the Custodia project area has plenty of exploration potential and remains relatively unexplored, with a total of 18 pegmatites mapped across the tenements and rock chip samples assaying as high as 431ppm lithium oxide.
Results of a 28-sample rock chip program from the pegmatites released to the market in January last year showed 10 samples that assayed at more than 100ppm lithium oxide, all with geochemistry suggesting the rock type is lithium, caesium and tantalum (LCT)-bearing pegmatite – the kind of rock that is developed globally to feed the lithium-hungry battery manufacturing market.
Gold Mountain seems well placed to feed the requirements of the global energy transition, with both lithium and rare earths on its books and a huge Brazilian landholding in an area where mining is seen as a force multiplier for local economies.
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By Andrew Duffy
