Highlights

  • Pursuit Minerals (ASX:PUR) has reported peak lithium brine grades of 995mg/L from DDH-3 packer tests at the Mito tenement, Rio Grande Sur, Argentina.
  • Four intervals exceeded 900mg/L, all from between 444 and 480 metres depth, compared with the current resource average of 424mg/L.
  • Rio Grande Sur hosts 1.264 million tonnes LCE at 424mg/L, comprising 705,000t Indicated and 559,000t Inferred.
  • Data from DDH-3 and DDH-4 will be incorporated in the next resource update, with prefeasibility study addendums expected shortly.

Highest Grades Yet at Mito

Pursuit Minerals has reported the highest lithium concentrations recorded at its Rio Grande Sur brine project in Salta Province, Argentina. Final packer test results from hole DDH-3 at the Mito tenement peaked at 995 milligrams per litre lithium between 444.2 and 445 metres depth. Four samples exceeded 900mg/L: 995 from 444.2 metres, 964 from 461.2 metres, 943 from 480.2 metres and 922 from 454.2 metres. These compare with the project's current resource average of 424mg/L.

Grade Profile by Depth

The deep zone is significantly richer than the upper section of the hole. Samples between 70 and 160 metres returned 298 to 498mg/L, intervals around 330 metres returned 558 to 584mg/L, and the richer brines sit from approximately 400 metres down. The vertical hole, collared at about 4,050 metres above sea level in the northern project area, finished at approximately 560 metres while still in lithium-bearing brine, leaving the lower extent undefined.

Packer Tests vs Resource Grade

Packer tests isolate short sections of a drill hole and sample brine from that interval. Most DDH-3 results cover 0.8-metre intervals, and no compositing has been applied. The existing resource is built from 10-metre composites, so individual peaks cannot be directly compared with the 424mg/L average. Grade is only one input; recoverable volume depends on porosity and specific yield, and processing economics are influenced by impurities such as magnesium, which are not reported for DDH-3.

Resource Update and Study Work

Data from DDH-3 and from DDH-4, drilled to 450 metres at the Demasia tenement, will be incorporated in the next resource update. A third hole is planned in the northern area to convert Inferred to Indicated. Prefeasibility study addendums examining expanded lithium carbonate and lithium chloride processing options beyond the initial 5,000-tonne-per-year operation are expected shortly. Site preparation is under way for evaporation ponds at the Sal Río II pilot plant.

What Comes Next

Key near-term catalysts are the next resource update incorporating DDH-3 and DDH-4 data, the PFS addendums and a 30-day continuous pumping test at the María Magdalena well targeted for 2027.