Patagonia Lithium Advances Resource Estimate with Strong Well Data

Interim Technical Review Highlights Porosity and Lithium Potential

Patagonia Lithium Ltd (ASX:PL3) has taken a significant step forward in delineating its lithium brine resources with an interim progress report from Atacama Water Consultants (AWC). The report synthesises data from seven drilled wells at the company’s Formentera and Cilon concessions in Argentina, focusing on lithology correlations, passive seismic data, and porosity metrics derived from core samples and gamma surveys.

Executive Chairman Phil Thomas emphasised the value of the work, particularly in correlating porous sand units across the aquifers and interpreting seismic data that partially delineates the sub-basin basement. This insight is crucial for the design of the initial production wells aimed at feeding the lithium carbonate demonstration plant, targeted to operate at 22,000 litres per hour.

Aquifer Characteristics Support Lithium Extraction Potential

The aquifer intervals dominating between 250 and 400 metres depth stand out with lithium assays and porosity exceeding 10%, which is notably twice the average porosity of comparable nearby salars. AWC’s geological assessment identified eight distinct units, including clastic-evaporitic sediments, volcaniclastic sequences, and the underlying basement rock, providing a robust stratigraphic framework for resource modelling.

Importantly, wells situated in zones of high conductivity, as indicated by magnetotelluric (MT) geophysics, correspond with elevated lithium concentrations and specific yields. Some wells could not be positioned in the highest conductivity zones due to water proximity constraints, yet those located within these zones delivered encouraging results.

Resource Estimate Update Hinges on Well Eight Completion

The previous Mineral Resource Estimate (MRE), released in July 2025, reported a maiden resource of 3.814 million tonnes lithium carbonate equivalent (LCE) and a drainable resource of 551,400 tonnes LCE. This comprises 14,800 tonnes in the Indicated category at 393 mg/L lithium concentration and 536,600 tonnes Inferred at 292 mg/L.

Completion of well eight, currently drilled to 362 metres depth, along with its gamma survey following installation of a PVC lining, will provide the final data required to complete the MRE. This milestone will feed into a follow-on scoping study, expected to refine project economics and development plans.

Ongoing Drilling and Pump Tests Reinforce Project Momentum

Patagonia Lithium’s drilling and pump testing campaign continues to yield positive indicators. Recent packer flow rates and porosity results have demonstrated the aquifers’ capacity to sustain lithium brine extraction at commercial rates. The company’s approach integrates multiple data streams, assays, core porosity, gamma logs, and geophysical surveys, to build confidence in resource continuity and quality.

The company confirmed no material changes to the assumptions underpinning the previous MRE, maintaining continuity in technical parameters and interpretations. This stability provides investors with a clear line of sight on project progression and resource reliability.

Investor Engagement and Project Footprint

Patagonia Lithium operates two major lithium brine projects in Argentina’s lithium triangle: Formentera/Cilon in Jujuy province and Tomas III in Salta province. The company also holds exploration concessions in Brazil targeting ionic rare earth elements, niobium, antimony, and lithium in pegmatites, strategically positioned near the largest niobium producer CMOC in Goiás state.

Shareholders are invited to an investor briefing on 19 August 2026, where Executive Chairman Phil Thomas will provide a detailed update on drilling progress, resource estimates, and next steps in project development.