The deployment of Fleet Space Technologies’ ExoSphere platform to image the subsurface structure of the Fermi Exploration Ltd-owned Perch River project in Saskatchewan’s Athabasca Basin is helping build confidence in a new high-priority exploration corridor, according to the latest release from the technology company.
Perch River is an early-stage, highly prospective exploration project situated in the Athabasca Basin, an area globally recognised for its structurally-complex mineralising systems, with uranium mineralisation often hosted within fault structures, but also at the unconformity between cratonic basement and younger sandstones, giving rise to their name: “unconformity-related uranium deposits”. For such challenging targets, early geochemical vectors and subtle alteration halos are often the first indicators of major discoveries.
In 2025, Fermi deployed Fleet Space Technologies’ ExoSphere platform to image the subsurface structure of the Perch River project, where previous soil and radon sampling had outlined an area of anomalous uranium, nickel, lead isotopes, rare earth elements in soil, alongside locally elevated radon. This sampling was followed in early 2025 by a combined magnetic and gravity survey, which indicated the presence of a potential fault structure in a structurally-complex location.
With traditional line-based geophysics precluded due to the presence of a 100-m-wide river within the target area, the modularised, highly flexible multiphysics surveys enabled by ExoSphere identified a deep low-velocity zone, termed by Fermi as the “Rapids Fault System”, which was used to refine drill targeting given its potential as a migration pathway for uranium-bearing hydrothermal fluids, Fleet Space explained.
Leveraging ExoSphere’s real-time 3D imaging of the major structural zone, drill hole PR25_04A was designed to test the western extent of the low-velocity zone – intersecting a 100-m interval (290-390 m downhole depth) containing intense alteration and strongly radiogenic lead isotope signatures consistent with those observed adjacent to uranium mineralisation in the Athabasca Basin. The intense alteration seen in several intervals between 287.9 m to 322.5 m downhole in PR25_04A is characterised by pervasive chlorite-hematite alteration and accompanied by intense shearing, fracturing and brecciation. These features indicate a significant structural and hydrothermal overprint, consistent with deformation and fluid movement along nearby fault zones – a common style of alteration of both mineralised and barren zones in unconformity-related uranium systems.
Additionally, results of up to 242.8 (²⁰⁶Pb/²⁰⁴Pb) and 0.15 (²⁰⁷Pb/²⁰⁶Pb) indicate a strong radiogenic lead signature typically associated with uranium mineralisation within a major fault structure, it noted. The anomalous results lie within the ExoSphere-identified low-velocity zone, further validating the Rapids Fault System as the key structural feature governing fluid flow and alteration at the property.
It explained: “Unconformity-related uranium deposits are historically challenging to detect due to their narrow geometries, deep settings and irregular alteration systems. Deployment of ExoSphere’s passive seismic surveys revealed: a 400-m-deep, subvertical low-velocity corridor, coincident with prior soil geochemistry anomalies and proximal to the Font du Lac Fault. The survey also hinted at the structural complexity of the area, further boosting confidence in the model.
This structural architecture provided critical insights for drill targeting, helping to guide hole PR25_04A into the zone now confirmed to host lead isotope results and alteration typical in unconformity-related uranium systems, according to the company.
“Agile geoscience is fundamentally reshaping how the world discovers and develops the resources needed for future industries and abundant clean energy,” Flavia Tata Nardini, CEO and co-Founder of Fleet Space Technologies, said. “By delivering real-time, 3D subsurface intelligence in some of the world’s most complex geological environments, ExoSphere is helping to identify critical structures earlier, reduce uncertainty faster and make more confident decisions with less environmental impact.”
By integrating ExoSphere ANT data with geochemical assays, mineralogy, airborne geophysics and structural observations, Fermi Exploration has increased its confidence in the Rapids Fault System as a high-priority exploration corridor, with further work pending – greatly enhancing future targeting activities in a structurally-complex geological environment.
Tata Nardini added: “This approach not only accelerates the path to discovery in tier-one mineral districts like the Athabasca Basin, but also strengthens the resilience of global mineral supply chains at a time when secure access to uranium and other strategic resources is increasingly vital for clean energy systems and future technologies.”
By accelerating the identification of deep, structural targets, ExoSphere continues to provide explorers in complex geological environments with a rapid, scalable and environmentally low-impact pathway to reduce uncertainty and improve drill targeting confidence at scale.