Gold Mountain Limited has reported additional high-grade rare earth mineralisation at its Ayrton Senna Prospect within the Down Under Project in Brazil, with assay results highlighting shallow mineralisation open at depth and strong magnet rare earth oxide ratios.
- High-grade TREO intersections up to 2,610 ppm
- Magnet Rare Earth Oxide ratios reach 51%
- Mineralisation open and potentially thicker at depth
- Metallurgical testing planned with ANSTO
- Follow-up auger and diamond drilling scheduled
New Assays Highlight Rare Earth Potential at Ayrton Senna
Gold Mountain Limited (ASX:GMN) has unveiled encouraging assay results from 24 auger drill holes at its Ayrton Senna Prospect, part of the Down Under Project in Brazil. The latest data confirm additional high-grade rare earth mineralisation, with Total Rare Earth Oxide (TREO) grades reaching up to 2,610 ppm over 2 metres and magnet rare earth oxide (MREO) ratios as high as 51%. These findings reinforce the scale and continuity of the rare earth system, which remains open at depth and close to surface in multiple drill sections.
Mineralisation Open at Depth in Saprolite Horizon
The mineralisation appears concentrated within the saprolite horizon of a deeply weathered profile, with Chemical Index of Alteration (CIA) values indicating strong weathering and enrichment. Drilling to date has only tested the upper portion of this weathered profile, with mineralised zones commencing near surface and extending to depths of up to 14 metres in some holes. The presence of halo magnet rare earth anomalies above significant TREO intersections suggests thicker and potentially higher-grade mineralisation may exist at greater depths, a hypothesis that will be tested by upcoming auger and diamond drilling programs.
Metallurgical Testing to Assess Extraction Potential
Selected mineralised samples will be sent to the Australian Nuclear Science and Technology Organisation (ANSTO) for ammonium sulphate leach testing. This work aims to determine whether the mineralisation is of the Ionic Adsorption Clay (IAC) type, which typically allows for more straightforward and cost-effective extraction of rare earth elements. The results of this metallurgical testing will be critical in assessing the economic viability of the mineralisation identified at Ayrton Senna.
Strategic Positioning and Next Steps
Gold Mountain holds 100% interest in 136 tenements across eastern Bahia, Brazil, with no known impediments to mining licenses, although some tenements overlap with a State Nature Reserve requiring environmental approvals. The company is advancing permitting for resource drilling at Ayrton Senna and awaits additional assay results from the ALS laboratory in Belo Horizonte. This latest data release significantly expands the prospectivity of the Down Under Project, complementing earlier high-grade discoveries at other prospects such as Irajuba and Capivara, where diamond drilling has confirmed thick zones of rare earth mineralisation with strong magnet rare earth oxide content. The company’s integrated approach of broad reconnaissance followed by targeted resource definition drilling positions it well to delineate a significant rare earth resource in Brazil.
Bottom Line?
Gold Mountain’s Ayrton Senna results open a new chapter in its Brazilian rare earth journey, but the true depth and economic potential hinge on forthcoming deeper drilling and metallurgical outcomes.
Questions in the middle?
- Will metallurgical testing confirm the mineralisation as Ionic Adsorption Clay type?
- How thick and continuous is the rare earth mineralisation below current drill depths?
- What environmental approvals will be required given overlap with protected areas?