The receipt of the final assay results from the recently completed deep sulphide mineral resource drill-out at the Prieska zinc/copper project, in the Northern Cape, has paved the way for the updated mineral resource due by mid-December, says ASX-listed Orion Minerals MD and CEO Errol Smart.

The “impressive” assay results, another significant milestone for Orion, will allow the exploration and development company to re-estimate and upgrade the current mineral resource, with the aim of elevating a substantial portion of the current inferred resource to a higher category resource.

“The in-fill drilling programme was primarily designed to increase the sample density for the deep sulphide mineral resource, with the objective of upgrading the previously reported deep sulphide inferred resource of 27.8-million tonnes grading 3.92% zinc (Zn) and 1.22% copper (Cu) for the Vardocube and Repli prospecting rights,” he explains.

“The extensive drilling programme has clearly demonstrated the substantial upside at Prieska, given the identification of significant additional massive sulphide and gold-rich target areas that have potential to add to the resource base and further enhance this already robust project,” Smart adds.

A total of more than 4 000 assay results from drill core samples have been received for the programme, which was completed on schedule on October 30.

The final 17 intersections included thick, high-grade massive sulphides, reporting results of 32 m at 5.05% Zn, 1.70% Cu, 0.30 g/t gold (Au) and 15.32 gt/silver (Ag) and 11.3 m at 4.42% Zn, 3.70% Cu, 0.51 g/t Au and 32.68 g/t Ag.

The assay results also confirm and upgrade key target areas for future drilling to extend mineralisation beyond the current mineral resource.

A newly identified gold-rich lens, with intersections of 2.27 m at 2.22 g/t Au, 2.80 m at 2.40 g/t Au and 2.40 m at 2.19 g/t Au, highlights the potential for additional mineralisation typical of volcanogenic massive sulphide systems.

In addition to establishing confidence in a substantial portion of the existing inferred resource being upgraded to an indicated resource level, the drilling programme confirmed high priority targets for future extensional drilling.

This includes the gold mineralisation in a newly identified subparallel lens outside the existing resource; open extensions beyond the thick, high-grade intersection in OCOD126; potential high-grade, copper-rich mineralisation to the south and south-east of OCOD137-D1; and confirmation that the double ore zone is extensive and provides a high-quality target offering the potential for significant additional mineralisation.

“These gold intersections fall outside of the known zinc/copper mineralised horizon and confirm the potential for outlining gold mineralisation in close proximity to the existing underground workings. This may add significant value to the project,” Smart concludes.