Patagonia advances exploration to define basement depth at Cilon

Highlights

• Patagonia analyses geophysical data from the Cilon project

• Survey results guide next steps in brine volume evaluation

• Seismic activity under review to confirm geological structure

ASX 200 exploration activity at the Cilon Lithium Brine Project in Argentina has entered a crucial stage, with geological data supporting further analysis of subsurface structures. The focus remains on evaluating the potential for lithium-rich brine in the region through advanced geophysical methods.

Patagonia Lithium (ASX:PL3) is prioritising the identification of the basement depth at its Cilon asset. The company recently reviewed reprocessed magnetotelluric data sourced from prior surveys conducted by Southernrock Geophysics. This initiative is central to better defining the reservoir potential across the targeted lithium zone.

Findings from Geophysical Reprocessing

Insights from the reprocessed data highlight correlations between deep resistive zones and elevated conductivity signals. These conductive anomalies are being interpreted as lithium-bearing brine accumulations, with the resistivity trends offering clues into the layering of subsurface materials.

The data also suggests that where resistivity begins to increase with depth, a potential transition to the geological basement may occur. However, without prior drilling intersecting this basement, its exact boundary remains hypothetical. The lack of a drilled basement rules out specific depths, prompting the team to rely on increasing resistivity as a probable indicator.

Challenges in Identifying the Basement

Determining the precise geological contact in the subsurface is complicated by electromagnetic propagation characteristics. These complexities introduce a degree of ambiguity in interpreting resistive and conductive layers, especially in real-world conditions. Therefore, multiple lines of geophysical evidence are being considered to mitigate this interpretive uncertainty.

Despite these constraints, the company believes that the most promising conductive zones remain the priority targets. These zones are believed to represent the best chances of encountering high-quality lithium brine accumulations. Until more definitive drilling occurs, estimates on basement positioning will rely on these indicators.

Planning Further Seismic Investigations

To reduce ambiguity, Patagonia is evaluating a two-kilometre seismic survey at Cilon. This would serve as a precursor to deeper drilling operations, enhancing understanding of whether the basement consists of volcanic formations or consolidated rock types. The seismic interpretation will guide strategic placement of the planned drill holes.

The seismic activity is expected to refine the geophysical model and help constrain the vertical extent of the conductive brine layer. This approach aims to establish a more definitive understanding of the basin's architecture and the nature of underlying formations, supporting future calculations of lithium resources.

Planned Drilling and Volume Assessment

One of the central activities at Cilon will be the execution of a new well, designated JAM 25-05, to a targeted depth that intersects the geological basement. The data obtained from this well will be instrumental in updating volume estimates for lithium-bearing brine within the area.

A clearer understanding of basement depth will allow for recalibration of resource potential, taking into account the vertical extent of the brine-filled formation. Establishing this measurement is key to quantifying the scale and commercial viability of the lithium deposit.

Broader Strategic Positioning

Patagonia Lithium's portfolio includes exploration rights across three properties located within Argentina’s lithium triangle. These consist of two assets in the Jujuy Province and one in Salta Province. This regional diversification supports a broader lithium exploration strategy across known lithium-rich basins.

With a focus on early-stage exploration and geophysical validation, Patagonia continues to position its projects for potential development. The outcomes of the Cilon analysis may influence future exploration priorities and investment direction across its other holdings within the lithium triangle.

Geophysical Complexity and Forward Approach

The company remains cautious about the non-uniqueness associated with electromagnetic data interpretation. This aspect of geophysics can yield different models based on similar data sets, depending on geological assumptions and processing techniques.

Despite the inherent uncertainties, the strategic use of seismic studies, along with the planned drill program, is expected to reduce interpretive gaps and provide clearer geological context. As these results emerge, they will underpin more refined project-level evaluations.

The next stage of activity at Cilon will focus on executing the seismic survey and preparing for drilling operations. Each new dataset is expected to contribute toward better geological modelling and resource assessment. These efforts reflect Patagonia’s commitment to methodical and data-driven exploration practices.

By enhancing its understanding of the subsurface environment, the company is positioning itself to make informed decisions about resource viability and potential development opportunities within Argentina’s lithium landscape.