London-listed miner Rainbow Rare Earths reports that, resulting from a recent structural and lithological review of its Burundi-based Gakara project, three large carbonatite bodies have been identified, representing the regional source of rare earth elements.

The structural and lithological review involved the reinterpretation of high-resolution geophysical data by TECT Geological Consulting, which was conducted in March and April.

The results confirm the highest priority areas for the ongoing exploration programme.

The review combined the structural information with the comprehensive mapping database accumulated by Rainbow over several years, as well as the geological knowledge derived from PhD research completed in December 2019.

This was used to define a data-driven, objective appraisal of sites where rare earth elements mineralisation, in the form of vein stockworks and / or breccias, are likely to have been more intensely developed. This work has defined 57 exploration targets.

In parallel with the structural review and targeting, Rainbow has been reviewing the historical mining and exploration data to ensure the full historical knowledge of the Gakara project is included in the next phase of exploration planning.

The combination of historical data, recent structural analysis and upcoming three-dimensional (3D) mineralisation models, will be used to refine the targets for ongoing exploration and trial mining, aimed at converting exploration targets into mineral resources.

This work is being led by mining consultancy CSA Global UK former MD Malcolm Titley, who is in the process of compiling mineral resource and exploration target three-dimensional (3D) models that comply with the standards defined by the Joint Ore Reserves Committee (Jorc) code.

Rainbow continues to operate trial mining and processing activities, demonstrating that the ore from veins found across the licence area is amenable to simple processing through gravity separation to produce a high-grade concentrate, which averages between 52% and 58% total rare earth oxide.

It states that this oxide is suitable for direct shipping with minimal radioactive elements or other deleterious by-products often associated with rare earth projects.

Rainbow CEO George Bennett says that since his appointment as CEO in August 2019, his focus has been to develop a deeper understanding of the deposit to realise the enormous potential it has to offer. “Understanding the structural controls that gave rise to the mineralisation is a key element to this.”

He adds that incorporating this knowledge into Rainbow’s 3D mineralisation models, alongside the existing mining and drilling data, will enable Rainbow’s initial Jorc resource base to better reflect project potential and help drive future exploration activities in the correctly targeted manner.