Patagonia Lithium has reprocessed magnetotelluric data to better understand the basement depth at its Argentine lithium projects, setting the stage for deeper drilling and seismic surveys to refine its resource estimates.
- Reprocessed 2023 magnetotelluric data reveals conductive layers linked to lithium brines
- No basement rock intersected yet; deeper drilling planned to 600m at Cilon
- Potential 2km seismic survey to clarify basement geology and improve resource modeling
- Recent mineral resource estimate stands at 551,400 tonnes lithium carbonate equivalent
- Exploration focused on Formentera/Cilon projects within Argentina’s lithium triangle
Context and Significance of Reprocessed Data
Patagonia Lithium Ltd (ASX – PL3) has taken a significant step forward in its exploration efforts by reprocessing magnetotelluric (MT) geophysical data collected during 2023 surveys at its lithium brine projects in northern Argentina. The updated analysis aims to better delineate the depth of the basement rock beneath the sedimentary lithium-bearing layers, a critical factor in accurately estimating the size and volume of its lithium resource.
The MT data, which measures subsurface resistivity, has highlighted conductive zones that correlate well with lithium concentrations found in drilling assays, notably a 580ppm lithium assay in one well. However, the basement rock itself remains undrilled, leaving some uncertainty about the full vertical extent of the lithium brine aquifers.
Drilling and Seismic Plans to Resolve Geological Ambiguities
To address this uncertainty, Patagonia Lithium plans to drill a 600-meter well at its Cilon concession, which is expected to penetrate closer to or into the basement. This deeper drilling will provide direct geological data to complement the geophysical interpretations. Additionally, the company is considering a 2-kilometer seismic survey to distinguish whether the basement consists of hard volcanic rock or a transition zone of consolidated sedimentary layers. This seismic data would help refine the geological model and reduce the ambiguity inherent in electromagnetic geophysics, which can produce non-unique interpretations.
Resource Estimate and Exploration Progress
Patagonia Lithium’s recent mineral resource estimate, released in July 2025, reported an inferred and indicated resource of 551,400 tonnes lithium carbonate equivalent (LCE), a substantial increase of 319% from previous estimates. This figure is based on lithium concentrations averaging around 294 milligrams per liter in the brine. The company’s exploration program has included multiple drill holes and pump tests, with encouraging lithium assays reaching as high as 1,100ppm at Formentera.
The ongoing integration of geophysical data with drilling results is crucial for Patagonia Lithium to convert inferred resources into higher confidence categories and to better quantify the total lithium volume. The company’s projects are strategically located within the prolific lithium triangle of Argentina, a region known for its high-quality lithium brine deposits.
Looking Ahead – Unlocking Lithium’s Potential
While the reprocessed MT data has improved understanding of the subsurface conductive layers, the absence of a clearly defined basement contact means that further work is essential. The planned drilling and seismic surveys will be pivotal in confirming the geological framework and enabling more precise resource modeling. For investors and market watchers, these developments represent a critical phase in Patagonia Lithium’s journey toward potentially expanding its lithium resource and advancing toward production.
Bottom Line?
Patagonia Lithium’s next drilling and seismic steps will be key to unlocking the full scale of its lithium resource.
Questions in the middle?
- Will the upcoming 600m well at Cilon confirm the basement depth and improve resource confidence?
- How will seismic survey results influence the geological model and future drilling targets?
- What impact could refined resource estimates have on Patagonia Lithium’s valuation and project financing?