Minbos Resources Ltd (ASX:MNB) has identified new targets through a recent airborne geophysical survey at its Ambato Rare Earths Project in Madagascar.
High-resolution helicopter magnetic and radiometric data was obtained by New Resolution Geophysics from two blocks within the Ambatofinandrahana area using its Xplorer system.
The western survey block is centred over the Ifasina and Marovoalavo project areas, and a second, smaller block over the Ankazohambo project area.
Geophysics interpretation results
Data was collected in an east–west direction with 100-metre line spacing and a nominal ground clearance of 20 to 30 metres.
Results confirm:
Radiometric anomalies have a strong correlation to rare earth occurrences at Ankazohambo as verified in 2018 drilling;
Two additional radiometric anomalies were delineated at Ankazohambo, one around 800 metres in length on the eastern ridge and another on the western ridge around 1.5 kilometres in length; and
Three radiometric anomalies were identified in the western survey block.
Radiometric interpretation
Despite thick laterite cover, the radiometric signatures provide a good indication of the form and extent of the rare earth (REE) mineralisation at the Ambato project.
At Ankazohambo, radiometrics highlight the exposed mineralised microsyenite dyke and show an extension to the known mineralised dyke, which is stronger and more extensive to the north.
The Marovoalavo prospect is represented by a set of sub-parallel dykes within a larger oval-shaped feature that may be a Pan African age granite intrusive.
Magnetic interpretation
Magnetic data products and images were used to compile lithological and structural interpretations for the two survey areas.
The magnetics in the Ankazohambo area showed little or no distinction between the non-magnetic limestone and quartzitic ltremo sediments, however, was present under the laterite covered Ankazohambo hill.
2019 work program
A 2019 work program is being prepared by the company and is likely to include soil sampling and mapping over the Marovoalavo anomaly, as well as additional soil sampling over Ankazohambo.
Soil sampling has previously been effective in identifying rare earth mineralisation.
- Jessica Cummins