Satellite Gold Exploration West Africa: 68-Point Proof

This is what happens when a client takes a satellite target set into the field and checks it, zone by zone. The satellite gold exploration work was ours. The reconnaissance that follows was designed, executed and written entirely by the client’s own geologist, on their own budget, with no involvement from us — which is exactly what makes their conclusions worth reading. They came back and reclassified the whole concession.

Over four days in late March 2026, a field team traversed a Birimian Supergroup concession in West Africa, moving between the target zones our satellite screening had flagged. They logged 68 distinct localities of gold mineralisation, each fixed by GPS and elevation. They were not there to prove the geology in the abstract. They had three concrete jobs: confirm that heavy diamond drilling rigs could physically reach the priority zones, choose ground for the pit, waste dump, processing plant and offices, and map the cocoa and food farms that would need compensation before anyone mobilised.

What they wrote at the end of it is the sentence that matters most in this entire report: the area “is not merely an alluvial site but hosts a robust primary hard-rock system.” That single reclassification moves a project from small-scale alluvial economics into hard-rock exploration economics — a different capital plan, a different drill programme, a different investor conversation.

68 GPS-logged localities in four field days — and every ranked zone returned quartz, veining or worked ground.

What satellite gold exploration delivered before the team flew out

Before the field team booked a flight, they already knew where to walk. Our screening had taken the whole concession — a large licence in dense, actively farmed cocoa country — and compressed it into 14 ranked target zones, delivered as georeferenced GIS polygons with a geological interpretation attached: host structure, likely controls, and where inside each polygon the strongest evidence sat.

That is the whole economic argument for satellite gold exploration in one sentence. A conventional programme would have put crews on the ground for weeks simply to work out which parts of the licence deserved attention — grid sampling, reconnaissance traverses, trenching across ground that turns out to be barren. This team skipped that phase entirely. They landed with a route already drawn, and spent all four of their field days on productive ground, logging 68 mineralisation localities, evaluating infrastructure sites and mapping farms.

Four questions, answered in four days

A field pass over a ranked target set answers four questions at once — and on this concession, all four came back with usable answers inside a single four-day campaign:

• ✔ Presence — is there mineralisation at the target? Every ranked zone returned evidence: quartz float, veining, gossan, oxidised material or historic workings.
• ✔ Character — primary hard rock, or secondary alluvial? In-situ boulders and fractured veins reclassified the concession as a primary hard-rock system.
• ✔ Access — can heavy rigs reach it? Rig routes, a bridge crossing point and flat rig-setup ground were all identified in the same pass.
• ✔ Land and community — who farms it? Cocoa, cassava and plantain farms were mapped for compensation before mobilisation, not after.

Answering all four at once is what makes a target set operationally useful rather than merely interesting. The team came home with a drill queue already sorted into build order.

Want this run on your own licence? Get a quote for satellite mineral detection, or map your ground first at mining.farmonaut.com.

How the target zones were generated

The client supplied a concession polygon and a target mineral. Our satellite-based mineral detection workflow then screened the whole area from orbit before anyone bought a plane ticket. The general shape of that process is public; the specific tuning is not, and this case study deliberately keeps the recipe generalised.

Satellite gold exploration works because reflected electromagnetic energy carries a fingerprint. Different minerals and alteration assemblages absorb and reflect at different wavelengths, so a multispectral or hyperspectral stack can distinguish an iron-oxide-stained, clay-altered, silica-rich patch of ground from ordinary weathered regolith. Layered on top of that spectral evidence, we read the landscape itself: structural lineaments and fracture corridors, drainage geometry, terrain roughness, radar backscatter that penetrates canopy, and thermal behaviour across seasons.

Two design choices in that cascade matter for a project like this one. First, seasonal persistence: a signal that appears in one dry-season scene and vanishes in the next is usually surface noise, not geology, and it gets filtered out. Second, canopy penetration: this is a densely vegetated cocoa-farming landscape, and optical sensors alone would have been badly handicapped. Radar backscatter sees structure that a true-colour image cannot, which is why the target set survived contact with a forest.

The deliverable the client took into the field was a set of ranked zones with a geological interpretation attached — host structure, likely controls, and where in each polygon the strongest evidence sat. Our Premium+ tier goes further and adds TargetMax™ drilling intelligence: recommended drilling angles to maximise the probability of intersecting a vein rather than drilling parallel to it, plus interactive 3D subsurface models of the vein structures. On a NE–SW fracture system like the one confirmed here, drilling angle is not a detail — it is the difference between a barren hole and an intersection.

Four days, 68 localities: what the ground returned

The traverse covered a landscape of gentle-to-steep hills and valleys typical of a Birimian metasedimentary basin, with elevations rising toward the eastern portion of the concession and ranging roughly 60 m to 110 m above sea level. That is low relief by exploration standards, which is good news for haulage and bad news for outcrop — most of the evidence had to come from float, excavated exposures and existing workings rather than clean cliff sections.

The evidence that reclassified the project

The pivotal observation was made at Zone 1. Large quartz boulders were found in situ on hilltops and slopes — not rounded, not transported, not sitting in a stream bed, but resting where they weathered out. In-situ boulders on a hilltop are the signature of a vein system eroding in place beneath them. Downslope, at the foot of those hills, the team confirmed fractured quartz veins trending NE–SW, a structural orientation the report describes as a regionally recognised high-grade gold corridor.

Put those two observations together and you have a coherent picture: a hard-rock vein set, oriented along a known regional control, shedding boulders onto the slopes around it. That is a fundamentally different asset from a placer deposit. Alluvial gold is finite, shallow and quickly worked out. A primary vein system has depth extent, and depth extent is what a diamond drilling programme is designed to measure.

Fig. 1 — Representative in-situ quartz boulder at the priority zone, compass for scale. Close-up field photograph reproduced from the client’s redacted report; no landscape, skyline or infrastructure is visible and no coordinates are attached.

Fig. 2 — A large quartz mass exposed in excavated ground, marker for scale. Boulders of this size resting in place, rather than rounded in drainage, are what separates a primary hard-rock interpretation from an alluvial one.

Fig. 3 — Quartz gravels with iron-oxide staining at a hill foot, pen for scale. Iron oxide alongside quartz is a classic surface expression of an oxidising sulphide-bearing vein system, and it is also one of the spectral signatures the satellite screening keys on.

Fig. 4 — Quartz boulders on the surface at a secondary zone. Rounding and position relative to slope are the field criteria used to separate transported float from in-situ material.

The ranked zone queue

The field team scored each zone on two axes that a drill manager actually cares about: how good the geology looks, and how hard it is to put a rig on it. The full ranking below is reproduced from the client’s summary table.

Read down the “field evidence” column and one thing stands out: there are no blanks. Every ranked entry returned something — in-situ veining, boulders, gravels, laterite with quartz fragments, or old workings. Not every zone is a drill target, and the team was clear about that, but not one of them was barren ground. For an early-stage screening exercise over a large concession, an all-positive presence result is the outcome you hope for and rarely publish, because it is usually the ambiguous middle that gets written up.

Zone 1 — the primary target

The report’s language about Zone 1 is unusually direct: it “demonstrates the structural integrity and scale required for a major discovery”, whereas other zones show only scattered quartz fragments. That distinction — integrity and scale versus scatter — is the difference between a vein system and a debris field.

Zone 5 — the immediate drilling candidate

Existing pits are an underrated form of validation. Somebody, at some point, dug there and kept digging — which is independent human evidence that the ground pays at surface. Combined with a satellite target and road access, that makes Zone 5 the lowest-friction way to get a rig turning on this concession.

One 35–45 metre bridge stands between a diamond drill rig and the best ground on the concession.

The bridge that unlocks the best ground

This is the finding that would never appear on a prospectivity map, and it is arguably the single most valuable line in the client’s report. Zone 1 — the exceptional target, the one with the vein system and the regional structural control — is on the wrong side of a river.

The team did not just note the obstacle. They walked the river and identified an optimal crossing point for a 35–45 metre bridge, then confirmed that the northern section beyond it offers relatively flat terrain suitable for rig setup. They also proposed locations for the pit, waste dump, processing plant and offices, and confirmed those sites sit in reasonable proximity to one another — which matters a great deal for haulage distance and site power, and which is exactly the kind of thing you can only settle by standing on the ground.

Framed commercially, one discrete piece of civil engineering converts the concession’s best geological target from unreachable to drillable. The report calls it “the key to unlocking the most prospective ground in the concession for heavy drill rigs”, and describes the river as “a manageable logistical challenge” rather than a blocker. That is a capital allocation question with a clean answer, and the field team handed it to management in a form they could act on.

Cocoa, compensation and community consent

Several of the target zones intersect active cocoa, cassava and plantain farms. The report is unambiguous about the consequence: a full crop compensation inventory must be finalised before drill mobilisation, and formal permission and support must be sought from village chiefs and the paramount chief.

One of the field team’s four stated objectives was to map the farms for future compensation purposes — planned in from the start, not discovered as an obstacle later. That ordering is the whole point. Crop compensation negotiated before mobilisation is a budgeted line item. Crop compensation negotiated after a rig is already parked in someone’s cocoa is a dispute with leverage on the wrong side of the table.

Zone 4 is the sharpest version of this problem. It carries large surface quartz boulders, but access is restricted by nearby buildings and a water facility. The recommendation is precision drilling combined with heightened community engagement — a narrower, more carefully sited programme rather than either abandoning the zone or bulldozing through the constraint.

The results, and what they were worth

Set against what the client set out to achieve, the campaign returned a clean sweep. Four objectives were stated at the top of their report. All four were met inside four field days.

The headline result goes further than any of those four. The client’s geologist reclassified the entire concession — from an alluvial site to a primary hard-rock system with depth extent. That is the reclassification that changes an asset’s capital plan, its mining method and the conversation it can have with investors, and it came out of a four-day campaign directed by satellite targets.

The programme now moves to diamond drilling, sequenced exactly as the field audit recommended: Zone 5 immediately, Zone 1 as the bridge comes in.

In the client’s own words

The most persuasive lines in this case study are not ours. They are the assessments the client’s own geologist wrote up after walking the targets — independently, on their own budget, with no input from us.

The geological upside of Zone 1 is exceptional.

Read those together and the arc of the project is clear. A satellite screening pointed at a polygon on the far side of a river; an independent geologist walked it and came back describing the structural integrity and scale required for a major discovery. That is the outcome this workflow is built to produce.

Where the time and money actually go

Traditional early-stage exploration walks a concession broadly, then narrows. Grid soil sampling, reconnaissance traverses across barren ground, trenching to find out whether a target exists at all — months of field time, at field-crew rates, in difficult terrain, much of it spent confirming that ground is empty. Satellite screening inverts the order: it narrows first, from orbit, and sends people only to the short list.

Across our exploration work generally, that reordering compresses early-stage timelines from months to days and cuts early-exploration cost by up to 80–85%. This project shows the mechanism concretely. Fourteen zones and a GIS file meant a team of geologists spent their four days logging 68 mineralisation localities, evaluating infrastructure sites and mapping farms — instead of spending the first three weeks working out where to start.

Run this loop on your own concession

The satellite gold exploration pattern this client followed is repeatable, and it is the one we recommend to every early-stage licence holder: screen from orbit, then validate on foot, then drill in access order.

1. Define the area. Send coordinates, a KML/KMZ, or a polygon, plus the country or region and your target mineral. Anything from a single licence to a multi-block portfolio works.
2. We screen it. We select the appropriate data source — multispectral or hyperspectral — acquire it, and run the analysis. Turnaround is 5 to 20 business days depending on area size and mineral complexity.
3. You receive ranked targets. High-potential zones, prospectivity heatmaps, estimated location and depth ranges, indicative quantity, geological interpretation covering faults, alteration and host rock, and seasonal anomaly validation — as a PDF plus georeferenced GIS files you can load onto a handheld GPS.
4. Upgrade if you are drilling. Premium+ adds TargetMax™ drilling intelligence — optimal drilling angles for higher ore-intersection probability, and interactive 3D subsurface models of vein structures and mineral distribution.
5. Validate on the ground. Send your geologists to the short list, exactly as this client did. Check presence, check whether the material is in situ, and check whether a rig can reach it.
6. Sequence by access, not by rank. Drill the reachable good target while you build access to the exceptional one.

Frequently asked questions

Glossary

Birimian Supergroup

A Palaeoproterozoic sequence of metasedimentary and metavolcanic rocks underlying much of West Africa, and the host of many of the region’s major gold systems.

In situ

In its original position. An in-situ quartz boulder has weathered out where it sits, rather than having been transported, which points to a vein source directly beneath.

Quartz float

Loose quartz fragments on the surface that have moved downslope from their source. Useful as a pointer, but not proof of a vein at that location.

Gossan / iron oxide staining

Rusty, iron-rich surface material produced by the weathering of sulphide minerals — often a visible expression of a mineralised system beneath, and a signature detectable spectrally from orbit.

Lineament

A linear landscape feature visible in satellite or radar imagery that commonly reflects an underlying fault or fracture — the structural plumbing that channels mineralising fluids.

Ground truthing

Physically visiting a remotely sensed target to verify what is actually there. The step this case study documents.

Diamond drilling

Core drilling that recovers a continuous cylinder of rock, allowing geologists to log and assay the mineralisation directly at depth.

Strip ratio

The volume of waste rock that must be moved to access one unit of ore in an open pit — a primary driver of open-pit mining cost.

This case study summarises a client-authored reconnaissance report published here in a redacted form at the client’s direction. Prospect and place names, GPS coordinates, elevations, the river and bridge crossing reference, and the author’s identity have been removed at source, along with 35 of 55 field photographs. The field observations, zone rankings, quoted assessments and recommendations are the client’s own; Farmonaut’s contribution was the satellite target set that directed the traverse. This is reconnaissance-stage exploration information and does not constitute a Mineral Resource or Reserve under JORC, NI 43-101, SK-1300 or SAMREC, nor does it constitute investment advice.