Pursuit Minerals Hits 809mg/L Lithium at Depth Rivalling Argentina’s Top Brine Projects
Key Takeaways
- DDH-3 at the Mito tenement returned 809mg/L Li from 399.2m to 404.0m depth — Pursuit Minerals' highest-ever lithium grade at Rio Grande Sur and among the highest individual brine assays reported across Argentina.
- Lithium grade increased 171% with depth between the two tested intervals, from 298.4mg/L at 156m to 809mg/L at 400m, signalling a progressively richer brine system below the surface salar expression.
- More than 20 packer samples from DDH-3 have been submitted for laboratory analysis, with pending results extending to approximately 550m depth — below the current high-grade zone.
- The drill rig has mobilised to DDH-4, continuing across the northern Rio Grande Salar and adding a second near-term catalyst stream alongside pending DDH-3 assays.
- High-grade brine at depth supports the potential for additional scale and higher-grade material to be added to the existing Mineral Resource, first announced on 2 February 2026.
Pursuit Minerals strikes exceptional high-grade lithium at Rio Grande Sur
Pursuit Minerals (ASX: PUR) has recorded its highest-ever lithium grade at the Rio Grande Sur Project, with drillhole DDH-3 returning 809mg/L Li from packer testing at 399.2m to 404.0m depth at the Mito tenement. The result places this individual brine assay amongst the highest-grade lithium results reported across Argentina’s major lithium brine projects and reinforces Mito as a key growth area for the broader Rio Grande Sur system.
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DDH-3 assay results — what the numbers show
Grade strengthens with depth
Two initial packer intervals have been returned from DDH-3, and the contrast between them is striking. The shallower interval, tested at 156.2m to 161.0m, returned 298.4mg/L Li. The deeper interval at 399.2m to 404.0m delivered 809mg/L Li, approximately 2.7 times the concentration of the shallower sample — a 171% increase in lithium grade between the two tested intervals.
That grade-with-depth relationship is one of the most compelling signals the result offers. It suggests a progressively richer brine system at depth within the Mito tenement, not a uniform or declining grade profile.
The grade-with-depth signal from DDH-3 aligns with subsurface structural work already completed at the project; advanced geophysics at Rio Grande Sur, including CSAMT reprocessing, had previously identified a large conductive target at depth consistent with a lithium brine system extending well below the surface salar expression.
| Interval | Depth From (m) | Depth To (m) | Lithium Grade (mg/L) | Notes |
|---|---|---|---|---|
| Packer 1 (Shallower) | 156.2 | 161.0 | 298.4 | Initial result from upper brine-bearing section |
| Packer 2 (Deeper) | 399.2 | 404.0 | 809 | Highest lithium grade recorded by Pursuit at RGS; ~2.7x the shallower interval |
How Pursuit’s result compares to Argentina’s top lithium projects
To contextualise the 809mg/L result, Figure 4 of the announcement compares it against reported average Mineral Resource grades of major Argentine lithium brine projects. An important caveat applies: the DDH-3 Packer 2 result is an individual brine sample from a discrete interval and is not directly comparable to Mineral Resource average grades, which reflect a broader body of data across an entire project.
With that distinction clearly in mind, the comparison is nonetheless instructive:
- Hombre Muerto West (Galan): 883mg/L Li
- RGS DDH-3 Packer 2 (Pursuit): 809mg/L Li
- Litica – Rio Grande: 595mg/L Li
- Pastos Grandes: 439mg/L Li
- Rincon (Rio Tinto): 416mg/L Li
- Centenario-Ratones (Eramet): 407mg/L Li
- Arizaro: 297mg/L Li
- Kachi (Lake Resources): 268mg/L Li
Aaron Revelle, Managing Director & CEO
“At 809mg/L lithium, this result compares extremely favourably with the average resource grades of many of Argentina’s most significant lithium brine projects. To encounter brine of this grade at approximately 400 metres is a highly encouraging result as we continue to build our understanding of the scale and grade potential of the Rio Grande Sur system.”
Understanding lithium brine exploration — why grade at depth matters
A salar is a dried salt lake found at high altitude in the Andes, where lithium-rich brines accumulate in porous rock and sediment layers beneath the salt crust over millions of years. Extracting those brines requires drilling into the aquifer system below and pumping the lithium-bearing fluid to surface.
Packer testing is a technique used to isolate specific depth intervals within a drillhole, allowing geologists to extract a representative brine sample from a defined section of the rock sequence rather than a mixed sample from the entire hole. Think of it as putting a valve at a precise depth to test what fluid is present at that exact point.
When lithium concentration increases significantly with depth — as it has in DDH-3, from 298.4mg/L at around 156m to 809mg/L at around 400m — that pattern indicates a potentially richer deeper brine system below the surface expression of the salar. It is an encouraging signal for resource potential, though individual packer results must be assessed in the context of a broader dataset before conclusions about Mineral Resource grade can be drawn.
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What’s next for Rio Grande Sur
DDH-3 is now complete to a final depth of approximately 560m, and the initial two assay results are just the beginning of a much larger analytical programme. The forward programme offers a clear sequence of near-term catalysts:
- More than 20 packer samples from DDH-3 have been submitted for laboratory analysis in total, with results pending
- Pending assays include intervals below the 399.2m to 404.0m high-grade zone, extending to approximately 550m — these will help define whether the high-grade brine continues deeper
- The drill rig has now mobilised to DDH-4, with drilling continuing across the northern Rio Grande Salar
- Results from DDH-3 and DDH-4 are expected to further refine understanding of Mito’s scale and grade potential
- High-grade brine at depth supports the potential for additional scale and higher-grade brine to be added to the existing Mineral Resource (as announced on 2 February 2026)
For investors tracking Pursuit, the news flow pipeline from here is well-defined. Pending DDH-3 assays from deeper intervals, combined with early results from DDH-4, give the company a series of potential catalysts that could progressively build the geological and hydrogeological picture at Mito and, over time, contribute to Mineral Resource growth at Rio Grande Sur.
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