Key Highlights

  • DDH-3 returned a peak lithium concentration of 995mg/L Li from 444.2m to 445.0m, the highest result Pursuit has recorded at Rio Grande Sur.
  • The peak assay is about 23% above the earlier best result of 809mg/L Li, which came from approximately 400m in the same drillhole.
  • Four samples exceeded 900mg/L Li and eight exceeded 800mg/L Li between roughly 400m and 510m depth.
  • The drillhole reached a final depth of about 560m and finished in lithium-bearing mineralisation.

Pursuit Minerals Limited (ASX:PUR) has reported final laboratory assays from Drillhole 3 (DDH-3) at the Mito tenement, in the northern part of the Rio Grande Sur Lithium Project in Salta Province, Argentina. The brine samples produced a peak lithium concentration of 995mg/L, the highest figure the company has recorded at the project and about 23% above the 809mg/L result announced earlier from the same hole.

Deep Brine Samples Lift the Project Record

DDH-3 was drilled to a final depth of approximately 560m, collared at an elevation of 4,050m above sea level. The program intersected several brine-bearing geological units, and a packer testing program was used to collect samples from selected intervals down the hole. The 995mg/L Li assay came from 444.2m to 445.0m and replaced the previous best of 809mg/L Li, which was taken from the interval 399.2m to 404.0m.

Six further intervals were reported with notable concentrations: 964mg/L Li from 461.2m to 462.0m, 943mg/L Li from 480.2m to 481.0m, 922mg/L Li from 454.2m to 455.0m, 867mg/L Li from 403.0m to 403.8m, 866mg/L Li from 428.2m to 429.0m and 827mg/L Li from 509.2m to 510.0m. In total, four samples exceeded 900mg/L Li and eight exceeded 800mg/L Li. Shallower samples were lower, with results of 444mg/L to 584mg/L recorded between 71.2m and 337.5m and 298mg/L from 156.2m to 161.0m.

Mineralisation Continues to the Base of the Hole

Pursuit stated that DDH-3 ended while still in lithium-bearing mineralisation, so the lower limit of the system at Mito has not been defined. The high-grade samples are concentrated in the deeper part of the hole, between about 400m and 510m, and the 827mg/L result at 509.2m shows brine of that tenor below 500m.

The assays follow preliminary DDH-3 results released on 10 September 2026. Managing Director and CEO Aaron Revelle described the final figures as the highest lithium grades recorded at Rio Grande Sur and said results approaching 1,000mg/L Li at depths beyond 400 metres reinforced the company's view of the project's scale and quality.

How 995mg/L Compares With Argentine Resource Grades

The company set the peak assay against average resource grades reported for other Argentine brine projects. Galan Lithium's Hombre Muerto West resource averages 883mg/L Li, Litica Resources' Rio Grande project averages 595mg/L Li, Pastos Grandes averages 439mg/L Li, Rio Tinto's Rincon resource averages 416mg/L Li and the Centenario-Ratones resource averages 407mg/L Li. Pursuit noted that 995mg/L Li is above each of those averages. The comparison is between a single sample result and reported resource averages, which are calculated differently.

The current Rio Grande Sur Mineral Resource, reported on 6 February 2026, stands at 1.264Mt of lithium carbonate equivalent at an average 424mg/L Li. It comprises 705kt Indicated at 443mg/L Li and 559kt Inferred at 405mg/L Li. Data from DDH-3, together with results from DDH-4 at Demasia, which was completed to 450m, will be added to the existing resource model, and Pursuit expects both holes to feed into its next Mineral Resource update.

Where the Drilling Leaves Rio Grande Sur

DDH-3 has produced the highest brine concentrations in Pursuit's Rio Grande Sur dataset, with a 995mg/L peak, four samples above 900mg/L Li and mineralisation continuing to about 560m. The result sits alongside a resource of 1.264Mt LCE at 424mg/L Li that was estimated before this drillhole was added.

Separately, Pursuit is finalising Pre-Feasibility Study addendums covering expanded lithium carbonate and lithium chloride pathways beyond the initial 5,000tpa operation, and is preparing site works for pilot plant evaporation ponds at Sal Rio II. At the Sascha Marcelina Gold Project, it is preparing the remaining Induced Polarisation surveys ahead of an initial drilling program.