PhosCo Uncovers High-Grade Copper and Silver Zones at Tunisia’s Simitu Project

Exceptional Copper Grades from Historical Workings

PhosCo Ltd (ASX:PHO) has unveiled striking high-grade copper and silver assay results from selective rock chip sampling at the King’s Eye prospect, part of its 100% owned Simitu Project in northern Tunisia. Among the standout figures are samples returning up to 21.3% copper and 100 grams per tonne silver, alongside antimony assays as high as 1.49% and zinc exceeding 30%. These results come from outcrop and historical mine dumps, reflecting mineralisation that was mined intermittently from the early 1900s to 1970.

The samples were specifically chosen to characterise mineralisation styles rather than provide a representative grade, but the scale of these assays signals a compelling exploration opportunity. PhosCo’s Managing Director, Taz Aldaoud, emphasised the significance of this discovery, noting the project’s potential as a second pillar alongside the company’s flagship Gasaat phosphate venture. This follows the company’s recent advances at Gasaat, where drilling results have been shaping imminent maiden resource estimates and strategic momentum Gasaat Phosphate Project advances.

Geophysical Surveys Reveal Depth Extensions Below Historic Mining

Complementing the surface sampling, PhosCo deployed ground geophysical techniques including Electrical Resistivity Tomography (ERT) and Induced Polarization (IP) surveys. These methods successfully mapped the extent of historical underground workings, which appear limited to about 40 vertical metres, consistent with historical records. More intriguingly, a strong IP chargeability anomaly at depths exceeding 100 metres suggests potential sulphide mineralisation well below the mined zones.

This geophysical evidence points to targets that could extend the mineralised system at depth, providing a tangible rationale for drill testing. The combination of high-grade surface assays and geophysical anomalies aligns with models of sediment-hosted vein-type copper deposits, analogous to the Jinman deposit in China. Such deposits often feature narrow, high-grade veins that may thicken into breccia pipes at depth, offering a pathway to substantial tonnage if confirmed.

Distinct Mineralisation Styles in a Complex Tectonic Setting

The Simitu Project spans 396 square kilometres along the Medjerda Thrust Zone, part of the tectonically complex Atlas Mountains. The geology hosts two distinct mineralisation styles at King’s Eye: a higher temperature sulphide assemblage rich in copper, antimony, arsenic, and silver, and a separate oxide zinc-lead mineralisation associated with karsted limestones and Triassic evaporites.

PhosCo’s rock chip assays confirm the sulphide mineralisation includes bornite, chalcopyrite, and sulfosalts such as tennantite and tetrahedrite, minerals typical of orogenic copper-silver systems. The zinc-lead mineralisation, meanwhile, is interpreted as Mississippi Valley Type (MVT), common in similar tectonic settings where salt diapirism has occurred. This polymetallic potential adds strategic depth to the project’s exploration appeal.

Next Steps Focus on Target Refinement and Drilling Preparation

With these encouraging early results, PhosCo is advancing detailed logging, mineralogical studies, and further geochemical analysis to refine exploration vectors. The geophysical data will be integral in defining drill targets, particularly to test the sulphide anomaly at depth. This exploration phase is critical to move beyond surface indications and historical mining footprints toward delineating a substantive mineral resource.

The Simitu Project’s early-stage status contrasts with PhosCo’s more mature Gasaat phosphate operations, where recent drilling success and capital raises have underpinned development plans strong drilling results at KM prospect. The addition of a promising copper-silver project in a historically underexplored region could diversify PhosCo’s portfolio and enhance its growth trajectory.