Litchfield Minerals Launches Geophysical Surveys at Oonagalabi and Silver Valley

Litchfield Minerals Moves From Theory to Field Testing With Three Geophysical Surveys Scheduled for July

Litchfield Minerals Ltd (ASX: LMS) is advancing its Northern Territory exploration strategy from desktop modelling to field-based testing, with three ground geophysical surveys scheduled to commence in early July 2026. The Litchfield Minerals geophysical surveys at Oonagalabi and Silver Valley represent a pivotal transition for the company, moving from conceptual frameworks into direct ground-truthing across two strategically important project areas.

According to the 30 June 2026 ASX announcement, the work represents the first test of the company's belt-scale mineral systems framework, developed through the BHP Xplor program, and will focus on two key projects: Oonagalabi in the Harts Range corridor and Silver Valley in the southern Davenport Province.

At Oonagalabi, a combined magnetotelluric (MT) and gravity survey will test a 2.5 kilometre deep conductivity anomaly, supported by up to $100,000 in co-funding from the Northern Territory Geological Survey's Geophysics and Drilling Collaborations (GDC) program.

At Silver Valley, an induced polarisation (IP) survey is scheduled to start in early July, targeting extensions to previously reported high-grade silver, lead and copper mineralisation, with results expected by the end of July 2026.

Managing Director Matthew Pustahya commented: "The completion of our mineral systems framework marked an important milestone for Litchfield. This next phase is about testing that model in the field and using the results to progressively refine our exploration targets across Harts Range and Silver Valley. By investing in high-quality geological and geophysical data, we're building a stronger technical foundation for future exploration. This systematic approach will help us better understand the geology, reduce exploration risk and ensure capital is directed to the highest-priority opportunities."

Litchfield Minerals Ltd describes itself as a capital-efficient copper explorer applying major-miner style technical discipline to early-stage exploration in the Northern Territory. The July survey program is central to that strategy.

What the Surveys Are Testing and Why It Matters

The geophysical work is intended to validate Litchfield Minerals Ltd's mineral systems framework and to sharpen future drill targeting rather than to support immediate drilling.

The company is staging work so that high-resolution geophysical data are collected first, interpreted in the context of its regional model, and then used to decide where drilling capital should be allocated.

The planned surveys, contractors and focus areas are summarised below.

For investors, this approach is designed to:

• Reduce geological uncertainty before drilling.
• Build a portfolio of higher-quality drill targets.
• Allocate capital selectively to the most prospective parts of Litchfield Minerals Ltd's tenure.

Oonagalabi: Probing a Deep Conductivity Anomaly With MT and Gravity

At the Oonagalabi Project in the Harts Range corridor, previous work identified a conductivity anomaly at approximately 2.5 km depth in the western group of tenements. Conductivity anomalies are zones where rocks conduct electricity more readily than surrounding rocks, often associated with sulphide-bearing mineralisation such as copper or nickel.

According to the announcement, Litchfield Minerals Ltd has contracted Planetary Geophysics to complete a combined MT and gravity survey designed to:

• Better define the geometry and depth extent of the 2.5 km anomaly beneath shallow cover.
• Refine priority exploration targets ahead of potential drill testing.

Key operational parameters include:

• MT station spacing: 1–2 km.
• Gravity station spacing: 500 metres.
• Start date: on or around 3 July 2026.
• Acquisition duration: approximately 30–40 days.
• Expected completion: mid to late August 2026, with processing in parallel.

The survey design was completed by Dr Kate Selway of Vox Geophysics, who will also process and invert the datasets. Data inversion is the process of converting raw geophysical measurements into subsurface models that can be interpreted geologically.

Furthermore, the ASX release notes that the survey builds on the 09GA-GA1 deep crustal seismic reflection line, using a similar deep-imaging mindset to extend subsurface coverage across Litchfield Minerals Ltd's Oonagalabi tenure.

Co-Funded Deep-Imaging Program

The MT and gravity work has been awarded up to $100,000 in co-funding from the Northern Territory Geological Survey under Round 19 of the Geophysics and Drilling Collaborations (GDC) program.

According to the announcement, the GDC program is a competitive scheme that supports exploration activities which improve geological understanding and mineral targeting in the Northern Territory, particularly in underexplored regions and at depth.

For investors following Litchfield Minerals Ltd, this contribution reduces the company-funded portion of the survey cost and supports the acquisition of high-quality data on a deep target that may not otherwise be tested rapidly.

Silver Valley: IP Survey Follows High-Grade Rock Chip Results

Silver Valley is described as a separate project in the southern Davenport Province, hosting epigenetic, structurally controlled, quartz-vein hosted silver, lead and copper mineralisation within the Murray Downs Dome. In simpler terms, the metals occur in quartz veins that were introduced into the rock along structures such as faults or fractures after the host rocks formed.

Previous reconnaissance rock chip sampling, as reported on 23 April 2026, returned high-grade polymetallic results, including:

• 378 g/t Ag, 0.91 g/t Au, 5.04% Cu and 44.9% Pb (sample SV2-04).
• 128 g/t Ag, 0.07 g/t Au, 0.02% Cu and 16.1% Pb (sample SV3-01).

These rock chips confirm the presence of high-grade silver and lead with associated gold and copper at surface. The planned IP survey is intended to assess whether similar sulphide mineralisation continues below surface and along strike.

According to Litchfield Minerals Ltd, the pole–dipole (PDIP) IP configuration has been chosen because it is well suited to detecting the sulphide mineralisation associated with this style of deposit and can test to moderate depths.

Key details provided in the announcement include:

• Project: Silver Valley (EL32241).
• Contractor: Australian Geophysical Services.
• Start: early July 2026.
• Objective: test for extensions to known high-grade mineralisation and refine priority drill targets.
• Results timing: by the end of July 2026.

For investors, the Silver Valley IP survey represents the earliest potential catalyst in Litchfield Minerals Ltd's current exploration schedule, as results are expected within weeks of survey commencement.

Educational Section: Understanding the Geophysical Techniques

Geophysical methods are central to the current program. For many non-specialist investors, terms such as MT and IP can be opaque. However, the following section explains these techniques in accessible language while retaining the key technical points.

Magnetotelluric (MT) Surveying

What is MT?
Magnetotelluric surveying is a passive geophysical technique that measures natural variations in the Earth's electric and magnetic fields to estimate how well rocks conduct electricity at depth.

• Data source: Natural signals from lightning and solar activity.
• Measurement: Changes in electric and magnetic fields at the surface.
• Output: A 2D or 3D image of electrical conductivity at depth.

Why does conductivity matter?
Rocks that contain sulphide minerals (which host metals such as copper, nickel, silver and lead) often conduct electricity better than surrounding rocks. MT can therefore highlight conductivity anomalies that may correspond to large mineralised systems, even several kilometres beneath the surface.

Investor relevance at Oonagalabi:

• MT is one of the few cost-effective tools that can investigate targets at around 2.5 km depth.
• A consistent, well-defined MT anomaly improves confidence when deciding where Litchfield Minerals Ltd should consider future drilling.
• Combining MT with gravity and other datasets helps distinguish between different possible rock types that could cause the anomaly.

Gravity Surveying

What is gravity surveying?
Gravity surveys measure very small changes in the Earth's gravitational field caused by differences in rock density.

• Denser rocks: produce slightly stronger gravity responses.
• Less dense rocks: produce slightly weaker gravity responses.

By measuring these variations at regular station spacing (in this case 500 m), geophysicists can infer changes in rock type and large-scale geological structures.

Why combine gravity with MT?

• MT focuses on electrical properties; gravity responds to density.
• When both methods highlight a coincident anomaly, the geological interpretation is often more constrained.
• At Oonagalabi, this combined approach supports a more detailed model of the deep anomaly before any drilling decisions are made.

Induced Polarisation (IP) Surveying

What is IP?
Induced polarisation is an active geophysical technique. An electrical current is injected into the ground using electrodes, then switched off. Instruments measure how the ground temporarily holds and releases this electrical charge.

• Rocks containing disseminated sulphide minerals often retain charge for longer.
• This property is referred to as chargeability.

Pole–dipole configuration (PDIP):

• One electrode is placed far away (the "pole") and a pair of electrodes closer together (the "dipole").
• This arrangement can be adjusted to probe different depths.
• It is commonly used in base and precious metal exploration.

Why IP is suited to Silver Valley:

• The mineralisation at Silver Valley is reported to be sulphide-hosted.
• IP is widely used to detect sulphide bodies that are not visible at surface.
• A strong, continuous IP anomaly that lines up with high-grade rock chips would give Litchfield Minerals Ltd a clearer basis for planning potential drilling.

Glossary of Key Technical Terms

BHP Xplor and Litchfield's Mineral Systems Approach

The announcement explains that Litchfield Minerals Ltd has built its exploration strategy around a belt-scale mineral systems framework, refined through participation in the BHP Xplor program.

Key aspects include:

• Treating the Aileron–Irindina corridor as an integrated mineral system rather than a collection of isolated prospects.
• Integrating MT, gravity, structural and isotopic datasets into a single geological model.
• Focusing on the geological controls that may influence copper and nickel mineralisation across the broader Harts Range tenure.

The MT and gravity surveys at Oonagalabi consequently form the next stage of testing this framework, with a stated objective of reducing uncertainty before drilling and refining high-priority exploration targets.

For investors, this indicates that Litchfield Minerals Ltd is using regional-scale data and major-company style workflows to guide its targeting, rather than relying solely on localised anomalies or historical workings.

Upcoming Catalysts and Exploration Timeline

The ASX announcement sets out a clear schedule of near-term activities and expected results across the two projects.

From an investor perspective, the key near-term event is the Silver Valley IP result set due by the end of July. These results have the potential to show whether subsurface chargeability anomalies correspond with the very high surface grades already reported.

The Oonagalabi MT results in Q3 2026 are more focused on deep targeting and may influence how Litchfield Minerals Ltd stages its next round of capital allocation for deeper exploration.

Why Investors Are Watching Litchfield Minerals Ltd

Within the framework of the 30 June 2026 announcement, several aspects may be of interest to investors following Litchfield Minerals Ltd:

1. High-grade surface mineralisation at Silver Valley
   Rock chip grades of 378 g/t silver and 44.9% lead, plus associated gold and copper, confirm high-grade polymetallic mineralisation at surface. The planned IP survey tests whether this continues at depth and along strike, which is a key question for any future drilling program.

2. Deep target at Oonagalabi
   A 2.5 km deep conductivity anomaly has been identified and is now being evaluated with purpose-designed MT and gravity surveys. This type of target typically requires high-quality geophysical data before drilling decisions can be contemplated, given the greater cost and complexity of deep drilling.

3. External co-funding support for geophysics
   The up to $100,000 GDC co-funding for the Oonagalabi survey reduces direct expenditure by Litchfield Minerals Ltd on this phase of work. For shareholders, this enhances capital efficiency for a technically demanding deep-imaging program.

4. Methodology aligned with major-miner practice
   The BHP Xplor-derived mineral systems framework and the integration of multiple datasets indicate a methodical approach to exploration. Litchfield Minerals Ltd describes its business model as using major-miner disciplines, structured decision gates and rigorous capital allocation to build high-quality exploration opportunities.

5. Clear near-term newsflow
   Silver Valley IP results in July and Oonagalabi MT outcomes in Q3 2026 provide defined points where new technical information will be released to the market. These datasets are expected to guide the next generation of drill targets across both projects.

Key takeaway for investors: According to the 30 June 2026 ASX announcement, the Litchfield Minerals geophysical surveys at Oonagalabi and Silver Valley mark the company's move from conceptual modelling into field-based testing, using MT, gravity and IP surveys to refine its target portfolio. With high-grade surface results already reported at Silver Valley, a deep conductivity anomaly at Oonagalabi, and geophysical results scheduled across July and Q3 2026, the coming months are positioned as an important period for data-driven refinement of the company's drill targeting and broader exploration strategy.

Want to Learn More About Litchfield Minerals' Exploration Projects?

With geophysical surveys now underway at both Silver Valley and Oonagalabi, Litchfield Minerals Ltd (ASX: LMS) is entering a pivotal period of field-based testing across its Northern Territory portfolio. From high-grade silver and lead at surface to a 2.5 km deep conductivity anomaly targeted with major-miner methodology, the company's exploration pipeline offers investors a clear series of near-term catalysts to follow. To learn more about Litchfield Minerals Ltd and its projects, visit www.litchfieldminerals.com.au.