Formentera Drilling Hits 335m Depth; Brine Samples Sent for Assay

Drilling Progress and Sampling Success

Patagonia Lithium Ltd (ASX – PL3) has reported significant progress in its Formentera lithium brine project located in Argentina’s lithium triangle. The company’s drilling at well JAM 25-05 has reached a depth of 335 metres without any operational issues, marking a key milestone in its exploration campaign. This vertical diamond drilling has intersected sandy and clay layers with encouraging volumes of lithium-bearing brines.

Two sets of brine samples, collected from depths of 98-104 metres and 134-140 metres using a single packer airlift system, have been dispatched to reputable laboratories Alex Stewart and ALS Global for assay. To enhance sampling accuracy at greater depths, Patagonia has engaged a specialised double packer system designed to minimise contamination and capture representative brine samples once the well reaches its terminal depth, projected at 600 metres.

Core Analysis and Environmental Compliance

Alongside brine sampling, four core samples measuring 15 centimetres each were extracted and sent to a laboratory in Buenos Aires for porosity analysis. These cores provide critical data on the permeability and transmissivity of the sedimentary layers hosting the brines, which directly influence lithium extraction potential.

In line with environmental regulatory requirements, Patagonia has also collected surface and subsurface brine samples for isotope testing, including oxygen-18 and carbon-14 analyses. These tests aim to understand the age and fluvial conditions of the brines, supporting the company’s environmental plan submission and sustainable development commitments.

Context Within Broader Exploration Strategy

The Formentera project forms part of Patagonia Lithium’s broader portfolio in northern Argentina, which includes the Cilon and Tomas III projects. The company’s recent Mineral Resource Estimate upgrade, released in July 2025, reported a substantial 319% increase in lithium carbonate equivalent (LCE) resources to 551,400 tonnes, underscoring the project’s potential.

Patagonia’s Executive Chairman Phillip Thomas highlighted the encouraging nature of the brine volumes encountered so far and confirmed plans to recommence drilling on 6 January 2026 after a brief holiday break. The company also intends to conduct a 48-hour pumping test at 335 metres to further characterise aquifer flow properties.

Next Steps and Market Implications

Looking ahead, Patagonia Lithium plans to drill one or two additional wells, undertake seismic surveys, and perform gamma porosity measurements before updating its Mineral Resource Estimate. These steps are critical to refining the resource model and advancing the project towards development.

With lithium demand continuing to surge globally, driven by electric vehicle and battery storage growth, Patagonia’s methodical approach to exploration and resource definition positions it well within the competitive lithium brine sector. Investors will be watching closely for the forthcoming assay results expected within six weeks, which will provide further clarity on the grade and economic viability of the resource.