Background
Globally, intrusion related gold systems (IRGS) display a broad range of styles, but key components in Western Australia are Proterozoic age carbonate rich host rocks, moderate structural deformation of host rocks, proximity to basin margin faults, and proximity to post depositional granite intrusions.
Due to high sulphide content buried (not outcropping) IRGS deposits are exceptionally well detected by geophysical methods such as magnetics, gravity, induced polarisation (IP) and/or electromagnetics (EM).
The Juno project is located in carbonate rich, low to moderately deformed Proterozoic host rocks on northern margin of basin proximal to major basin structures.
The Abra deposit is located 100km south-east of Juno in the same Proterozoic basin and displays IRGS type features. Abra was discovered following airborne geophysical surveys.
The discrete magnetic feature at Juno is approximately 5km x 5km in size. By way of comparison, the discrete magnetic target at Havieron is 1km x 1km in size currently 8.4Moz AuEq.
Historic Work Programme
An airborne magnetic survey which was carried out in the early 90s identified the Juno target. This was followed up by ground based magnetic and gravity surveys which were completed in the mid 1990s. This work was carried out by Australian companies Newcrest Mining and Pasminco.
Pasminco recognised the coincident nature of the Juno magnetic and gravity features and applied an Iron Oxide Copper Gold (IOCG) model. IOCG deposits are large and often display coincident magnetic and gravity signatures.
Pasminco modelled the geophysical data and planned a single drillhole to test the target – HD1
HD1 failed to intersect the source of the magnetic and gravity feature as it was poorly sited. The hole also failed to achieve target depth due to the small capacity of the drilling equipment.
However, HD1 intersected rocks which displayed thermal alteration and disseminated sulphide mineralisation suggesting close to source – skarn type features as were seen at Havieron.
Follow up work in the early 2000s by Udu Resources consisted of re-evaluating Juno as an IOCG target. Udu conducted a limited ground Electro Magnetic survey over a part of the Juno target which was successful in detecting a strong conductor.
However, the aerial extent of the survey was insufficient relative to the size of the Juno target. Udu also drilled several drillholes UHC1-4 to test the target. All holes failed to penetrate the surface rocks due to the limited capacity of the drilling equipment.
Since the early 2000s there has been little to no work carried out in the Juno area. Callum Baxter applied for the current licence in 2022 and the licence was granted in 2023.
Historical data from the 90s and early 2000s is poorly constrained and more modern surveys are required to better locate and ‘see’ the target using up to date modelling techniques, as used in the Havieron discovery.
Current Work Programme
GEO plan to use modern drilling equipment and techniques to further explore the Juno target. An indicative timeline of activity is outlined below:
Progress To Date
Exploration Licences
The Company had applied for two further Exploration Licences, E52/4391 and E08/3744, adjacent to the current Exploration Licence E08/3497 in Western Australia, via its wholly owned subsidiary Juno Gold Pty Ltd. In February 2025, the company also applied for another Exploration Licence, E08/ 3792, north of the current Exploration Licence 08/3497. Callum Baxter, exploration geologist consulting to the Company, had identified potential exploration targets within these licences which share geophysical similarities to the target within Licence E08/3497.
On the 5th May 2025 Exploration Licence E08/3744 was granted, forming the western parts of the Juno Project and on the 8th May 2025 the Exploration Licence E52/4391 was also granted, forming the eastern parts of the Juno Project. This increased the total granted tenure from 275 km² to 450 km².
Licence E08/3792 is currently pending. If granted the new Exploration Licence 08/3792 will cover an area of 194 square kilometres, and upon grant of applications the total area of the Juno project will increase from 450 square kilometres to 644 square kilometres covering multiple magnetic features.
The Company is using an intrusion related deposit exploration model seeking to locate precious and base metal mineralisation, similar to that at the Havieron and Telfer deposits in northern Western Australia.
Aeromagnetic Results
GEO’s main focus at Juno is targeting Intrusion Related Gold Systems (IRGS) similar to Havieron and Telfer. Havieron and Telfer are large gold and copper deposits located in the north of Western Australia.
Gold and copper mineralisation at Havieron was discovered following exploration drilling of a strong discrete magnetic feature. Havieron also displays a coincident gravity response.
GEO has targeted the northern parts of E08/3497 as its initial area of focus. Processing and imaging of aeromagnetic data covering the northern portion of the main Juno magnetic feature is complete (Figure 1). Imaging has revealed the data is of high quality and very detailed in nature.
The new aeromagnetic data confirms the location, highlights the strong intensity and verifies the large size of the Juno magnetic feature. This new detailed aeromagnetic data reveals structures and other features not seen in historical, lower resolution, magnetic data. The aeromagnetic survey was carried out during October 2024 using a fixed wing aircraft at 50m line spacing.
Figure 1 – Newly acquired 50m line spaced data overlayed on historic 400m line spaced data.
Figure 1 – Newly acquired 50m line spaced data overlayed on historic 400m line spaced data.
LiDAR Data Delivery
GEO received the complete processed LiDAR package for the Juno Project, including 0.5 m- and 1 m-resolution Digital Terrain Models (DTMs) and high-resolution ground imagery, completing the survey announced in December 2024.
Sub-20 cm Spatial Accuracy – The LiDAR dataset was levelled against multiple ground-control points, delivering spatial accuracy better than 20 cm—sufficient to detect subtle topographic and geological features critical for drill-target definition.
Integrated Targeting Workflow – The LiDAR dataset was levelled against multiple ground-control points, delivering spatial accuracy better than 20 cm—sufficient to detect subtle topographic and geological features critical for drill-target definition.
Ground Gravity Data
- Analysis confirms a significantly large residual gravity response
- Large gravity response spatially aligns with prominent magnetic feature at Juno
- Alignment is typical signature of IRGS style mineralisation as per Havieron copper gold deposit
Ground gravity data was collected over the central north of the Juno Project area from late November to mid December 2024. A total of 1400 ground gravity observations were taken at station spacings of 400m x200m, and 200m x 200m where added resolution was required. Post processing and imaging of the gravity data was completed during late December 2024 and early January 2025. Delivered products include high resolution raw and residual gravity data.
The newly acquired 2024 ground gravity data has successfully confirmed the gravity response that was initially suggested by the historic work from the 1990s. Importantly, the Company’s recent detailed and spatially accurate gravity work has successfully identified a significant residual gravity response that is coincident with the large magnetic response at Juno (Figure 1).
The residual gravity response covers an area of approximately 4km x 2km (8sq kms) with a peak amplitude of 2mgal. The magnetic feature covers an area of approximately 5km x 2km (10sq kms) with a peak response of +1000nT. Coincident magnetic and gravity response of this size and amplitudes is consistent with IRGS and IOCG (Iron Oxide Copper-Gold) type deposits.
The Company is targeting IRGS type mineralisation at Juno. By comparison, Havieron, a large IRGS gold and copper deposit (+8Moz gold equivalent) located in the north of Western Australia, displays a 1km x 1km (1 sq km) magnetic response with a coincident gravity response peaking at 0.5mgal. The intensity of the gravity response at Juno is more elevated than Havieron, and the footprint of the coincident response at Juno is several times larger which illustrates the significant size of the opportunity at Juno.
Several historic exploration holes have been attempted at Juno since the mid 1990s to the early 2000s (Figure 2). Several holes targeted the large Juno magnetic feature but failed to reach the target depth due to limited capacity drilling equipment. Modern drilling equipment has the ability to overcome these earlier shortcomings, and advanced modelling of detailed subsurface geophysical data provides accurate 3D models for efficient drill targeting.
Figure 1 – Juno Aeromagnetics and Ground Gravity
Figure 2 – Juno Project Aeromagnetics (image) with Residual Ground Gravity (contour) and historic drilling.
Figure 1 – Juno Aeromagnetics and Ground Gravity
Figure 2 – Juno Project Aeromagnetics (image) with Residual Ground Gravity (contour) and historic drilling.
Geophysical Modelling
- Integrated 3-D magnetic-and-gravity modelling has refined an IRGS style target and places the top of the primary body approximately 600m below surface.
- Unconstrained and forward models converge on a single, coherent footprint spanning roughly 4 km × 2 km, confirming the system’s large scale.
- Historic hole PHD001 stopped just short of the newly modelled body, highlighting immediate drill potential.
- Ground-based electrical geophysics to integrate with modelling data to allow finalisation of drillhole locations ahead of Juno’s maiden drilling programme.
Juno Project 3D unconstrained results showing coincident magnetic and gravity model bodies.
Juno Project 3D Forward Modelling results showing primary target.
Successful Execution of Heritage Agreement
- Heritage Agreement successfully executed with Traditional Owners.
- Framework spans early reconnaissance through ore-body development, protecting Aboriginal Sites and Country while enabling collaborative consultation.
- Completion of the Agreement removes a key permitting hurdle and allows GEO to accelerate systematic drilling and advanced exploration programmes.
Results of Electrical Geophysics
- Electrical Geophysical programmes completed at Juno Project comprising Induced Polarisation (IP) and Electromagnetics (EM).
- IP and EM responses successfully modelled from subsurface data.
- Geophysical responses observed have upgraded the Juno Project from an IRGS perspective.
- IP and EM results integrated with existing subsurface models, and proposed maiden drillhole locations confirmed.
- Maiden holes will be drilled and expected to be vertical
Dipole-Dipole IP 2D Section Lines. Resistivity (left) showing geological contacts and Conductivity (right) showing chargeability responses. Associated with eastern and western margins of magnetic and gravity bodies.
Dipole-Dipole IP 2D Section Lines on modelled 3D magnetic and gravity bodies. Resistivity (left) and Chargeability (right). 3D model bodies from RNS dated 28 May 2025.
Fixed Loop EM Conductors with modelled 3D magnetic & gravity bodies. 3D model bodies from RNS dated 28 May 2025.
Fixed Loop EM Conductors, IP resistivity (left) / conductivity (right) sections, with modelled 3D magnetic and gravity bodies. 3D model bodies from RNS dated 28 May 2025.
Modelled 3D magnetic and gravity bodies with Fixed Loop EM conductors and proposed diamond drillhole locations. 3D model bodies from RNS dated 28 May 2025.
Drilling Contractor Appointed
- DDH1 appointed as drilling contractor for maiden campaign at the Juno Project
- Reuniting DDH1 with Geo’s JV partner Callum Baxter, who worked with DDH1 on Greatland Gold’s maiden drill holes at Havieron in 2018
GEO Exploration Limited entered into a contract with DDH1 Drilling Pty Ltd (“DDH1”) in August 2025 to undertake the Company’s maiden diamond core drilling programme at the Juno Project in Western Australia.
DDH1, part of the Perenti Group (ASX: PRN), is Australia’s leading and largest provider of diamond core drilling services, with a modern fleet, highly experienced crews, and an industry-leading safety record. The company has extensive experience in Western Australia, including Greatland Gold’s (LSE:GGP) maiden drill holes at the Havieron deposit in 2018.
This appointment also reunites DDH1 with GEO’s JV partner Callum Baxter, who was directly involved in Greatland Gold’s work at Havieron in 2018, combining proven expertise in exploration success. Support personnel assisting with drilling activities were also part of the early Greatland team working at Havieron.
Commencement of Maiden Drilling Programme
- Maiden drilling programme commenced at the Juno Project with the first hole JUD001 and second hole JUD002.
- Major milestone for GEO — expedited and prioritised to commence drilling at the earliest opportunity.
- GEO technical team on site alongside DDH1.
- JUD001 and JUD002 drilling and targeting a large IRGS precious and base metal system defined by integrated geophysical modelling and geophysics.
GEO Exploration Limited announced in August 2025 that the commencement of its maiden diamond drilling programme at the Juno Project, located in Western Australia. The programme consisted of two holes with the first drill hole JUD001 and JUD002.
This marked a significant operational milestone for the Company, following successful mobilisation of equipment and site preparation. GEO’s technical team is on site and working in collaboration with DDH1 Drilling Pty Ltd Australia’s leading diamond drilling contractor. All activities are being conducted in accordance with rigorous safety protocols and operational standards.
The drilling programme tests a 4 km × 2 km geophysical target interpreted as an Intrusion-Related Gold System (IRGS), defined through integrated 3D gravity and magnetic modelling, and further refined by Induced Polarisation (IP) and Electromagnetic (EM) survey data. Initial drilling will be done with a phased approach designed to incorporate geological results into ongoing targeting.