Armada Metals Ltd (ASX:AMM) has kicked off a series of ground-based natural source audio-magnetotelluric (NSAMT) surveys over the Libonga-Matchiti Trend at Nyanga Project in Gabon.
The survey is designed with a depth of investigation (DOI) of up to 1,000 metres below the surface to follow up on targets where magmatic sulphides were encountered during a phase one drilling program.
Notably, the Libonga-Matchiti Trend (LMT) is considered highly prospective for nickel-copper-PGE mineralisation hosted in potential magmatic massive sulphide accumulations within ultramafic units.
Surveys will start at the Libonga South target and, if successful, will then be moved to other high-priority targets along the LMT and then to the high-priority regional Ngongo and Yoyo targets.
The completion of data collection is expected by the end of September 2022 with the final processed results expected towards the end of October 2022.
Impact scale and prospectivity
Armada managing director and CEO Dr Ross McGowan said: “Following the positive technical results of our recent Phase 1 drill program, we are very excited to mobilise this ground geophysical survey on our Nyanga Project.
“With a better understanding of the geology and visible magmatic sulphides observed through the intersected magmatic host rocks, this survey seeks to directly detect metal and sulphide accumulations subsurface and will drive future drill testing.
“The results of this survey will impact not only the exploration pipeline for the Nyanga Project but also its scale and extent of prospectivity.”
Survey program
NSAMT systems calculate ground resistivity by measuring the magnitude of naturally occurring electric and magnetic fields.
Resistivity values are calculated from these measurements and used to create 2D and 3D images of the subsurface. Magmatic sulphide accumulations are defined by extremely low resistivity values.
The results of the survey will be compared with the Xcite™ airborne electromagnetic data and physical property measurements on core from the phase one program, to provide a basis for ranking AMT anomalies to define targets for the next phase of drilling.
Geophysical Surveys and Systems cc (GSS), South Africa, has been contracted to carry out the surveys and is currently on site.