Tempest Minerals Ltd (ASX:TEM) has completed regional Electron Paramagnetic Resonance (EPR) surveys across its Yalgoo and Mt Magnet projects in Western Australia with more than 250 potentially mineralised responses detected.
This work confirms the prospectivity of the company’s portfolio and the correlation of the responses to multiple existing targets provides further evidence as Tempest moves towards drilling multiple areas in the coming quarter.
Data from the survey’s first phase has yielded at least 250 metal-related anomalies. At least 50 are in the Meleya Project area and five are spatially proximal to a number of established high-priority exploration localities including the high-profile Orion target and the Master target at which TEM is drilling.
What is EPR?
EPR is the process of measuring the differing spectra emitted as a result of unbound electron spin changes and relaxation from an excited state due to the influence of a magnetic field.
In addition to the magnetic field, unpaired electrons are also sensitive to their local environments.
The resulting interaction between the electron and the nuclei can provide a great deal of information about the sample including providing information about the number and identity of nuclei in a complex as well as their distance from the unpaired electron.
Committed to innovation
Tempest Minerals is committed to innovation in all aspects of its work. This focus includes adapting new technologies that have the potential to advance its operations.
EPR was identified in 2021 and researched as a potential tool for advancing non-invasive exploration at its projects in Western Australia.
Tempest entered into a partnership in 2022 with Southern Sky Energy, which is a primary provider of proprietary EPR services in Australia.
Together, the team designed a ‘broad brush’ regional scale survey across the Yalgoo and Mt Magnet portfolios.
Trial scoping survey
This trial scoping survey using the first two of a number of possible phases of the survey technique (airborne with ground tie-in points) was completed recently.
As with all potential field and remote sensing methods, EPR must be cross-referenced with a wide variety of spatial, mapping and geochemical data to understand their full relevance.
Factors such as signal interference and non-unique solutions are possible, meaning that all targets shall be assessed against other geoscientific datasets prior to drilling.
EPR technology
EPR has been extensively implemented across a wide variety of industries including material science, biomedical, food quality control and hydrocarbon exploration.
Although previously having limited mainstream adoption within the metalliferous sector, EPR has been used in Australia since at least the 1990s and used on several occasions to identify mineralisation in exploration of several commodities including base metals.
More recent work in Western Australian gold exploration identified that “As the emphasis in exploration changes to more difficult terrains, the suitability of EPR needs to be widely tested. These preliminary results from Western Australia suggest that EPR may have some significant role to play in the search for deeply buried gold deposits.”
When certain ground conditions can be met, this spectroscopic technique has the potential to detect hydrocarbons, metals, halogens, biomarkers and other pathfinder elements potentially associated with precious and base metal deposits at significant depth.
This technique can advance regional targeting - for example - in the absence of other large grid-based soil or shallow sampling by disregarding areas that have no EPR signal and focusing on priority areas. EPR augments and can be used in conjunction as another layer of evidence with more well-known methods of standard exploration methods such as magnetics and drilling.
Next steps
The next steps for Tempest at these properties include:
- Validation of results with comparative analysis to other datasets.
- Ongoing fieldwork including large-scale mapping and surface sampling programs.
- Multiple drilling programs planned for 2022 and 2023.