Patagonia Lithium has advanced drilling at its Formentera lithium project in Argentina to 308 metres, revealing encouraging porosity and brine characteristics that suggest strong lithium potential. Six successful packer tests indicate increasing brine concentration and flow rates, with further drilling planned to deepen the resource understanding.
- Drilling at Formentera reaches 308m with high porosity sands
- Six packer tests show increasing specific gravity and conductivity
- Brine flow rates exceed 1,000 litres per hour
- Core samples sent for assay to independent laboratories
- No material changes to prior Mineral Resource Estimate
Drilling Progress and Geological Context
Patagonia Lithium Ltd (ASX – PL3) has reported significant progress at its Formentera lithium brine project in Argentina, with Well 6 reaching a depth of 308 metres as of early February 2026. The drilling has encountered sandy and silty units exhibiting moderate to high porosity between 80 and 220 metres, a promising sign for lithium brine accumulation. The company has installed steel casing to 218 metres to stabilise the borehole and prevent collapse, reflecting careful operational management in challenging subsurface conditions.
Executive Chairman Phillip Thomas highlighted the encouraging nature of the geological findings, noting the increasing specific gravity and electrical conductivity of the brines sampled. These parameters are key indicators of dissolved ion concentration, which correlates with lithium presence in brine deposits. The porosity observed is particularly notable given the sedimentary basin context, where such depths often transition to harder rock formations.
Packer Tests and Brine Characteristics
The company has completed six packer tests at various depths (103m, 130m, 155m, 195m, 225m, and 302m), all yielding successful results. These tests measure the flow and quality of brine within discrete intervals of the well, with flow rates exceeding 1,000 litres per hour, indicating good aquifer permeability. Specific gravity values have risen from 1.02 to 1.10 gm/cm³, while electrical conductivity has increased substantially, suggesting a higher concentration of dissolved minerals.
Brine samples collected during these tests have been dispatched to reputable laboratories in Jujuy and Salta for detailed assay analysis. While visual estimates of mineral content are not reliable proxies for lithium concentration, the laboratory results will provide definitive data on lithium grades and other relevant elements. The company emphasises that lithium ions are only detectable through assay, underscoring the importance of these forthcoming results.
Resource Implications and Future Work
Patagonia Lithium confirmed that there have been no material changes to the assumptions underpinning its July 2025 Mineral Resource Estimate (MRE), which currently stands at 551,400 tonnes of lithium carbonate equivalent (LCE). The ongoing drilling and testing are expected to refine and potentially expand this resource base. The company plans to deepen Well 6 to a projected 600 metres and conduct additional geophysical surveys, including seismic and gamma porosity assessments, to better delineate the lithium brine aquifers.
Beyond Formentera, Patagonia Lithium maintains a diversified portfolio with projects in the lithium triangle of Argentina and exploration concessions in Brazil targeting rare earth elements and niobium. This broad approach positions the company to capitalise on multiple critical mineral markets amid growing global demand.
Operational and Regulatory Considerations
The drilling program has proceeded with minimal interruptions, reflecting robust site management and compliance with environmental and regulatory requirements. The Formentera concession holds secure tenure, and all necessary permits have been obtained. Sample security protocols and quality assurance measures are rigorous, involving chain-of-custody procedures and independent laboratory verification to ensure data integrity.
As assay results become available, they will be critical in validating the economic potential of the brine resource and informing subsequent development decisions. Investors and analysts will be watching closely for these updates, which will shape Patagonia Lithium’s near-term exploration strategy and market positioning.
Bottom Line?
With strong early drilling results and assays pending, Patagonia Lithium’s Formentera project is poised for a pivotal phase in its resource development journey.
Questions in the middle?
- What lithium concentrations will the pending brine assays confirm?
- How will deeper drilling to 600m impact the current resource estimate?
- What are the timelines and expected outcomes for the planned seismic and porosity surveys?