Exploration drilling at Harmony Gold’s Kalgold openpit operation in the North West province outlines an expanded, robust mineralised system that extends beyond the current limits.

“Our exploration strategy targets highly prospective, underexplored terrains and mining districts to discover and develop gold deposits,” the company said on Monday, adding that resource development drilling has outlined a mineralised zone that now comprises over 2.1 km of strike and extends to in excess of 300 m below surface.

“The intersections show good continuity of geology and mineralisation and present an exciting organic growth opportunity for Harmony,” said CEO Peter Steenkamp.

An updated mineral resource estimate will be prepared, incorporating the exploration data and will form the basis of prefeasibility studies planned for 2019.

The updated mineral resources for Kalgold will be released as part of the company’s annual reporting for the 2018 financial year.

The mineralisation outlined in the drilling is hosted in a banded iron formation (BIF), which Harmony says is an extension of the same structural-geological setting of the known deposits at D Zone, A Zone, Watertank and the Windmill openpits.

New mineralised zones defined outside of the current resource limit include strike extensions north of the current Watertank openpit, significant drill intercepts in the “Pillar” zone that separates the A Zone and the Watertank pits, as well as new areas of mineralisation in the Western Limb BIF at depth and along strike to the south of A Zone.

Additionally, a new zone of mineralisation is developing subparallel with the Watertank lodes at the Spanover Border prospect, while drill intercepts from within the current resource limit demonstrate good grade continuity, Harmony noted.

Higher-grade zones of mineralisation with in excess of 2 g/t gold occur associated with shallow, north plunging, crosscutting quartz veins which are developed along the main line of lode, the company added.

Further, Harmony started a brownfield drill campaign at the project in October 2017 to test the potential to merge the separate pit areas into a major mineralised system and to test the strike extensions of the mineralised zone towards the north and south of the existing openpits.

Some 16 400 m of diamond and reverse circulation drilling has since been completed, leading the company to a positive resource growth outlook.

The system is open-ended along strike and remains open at depth, while to the north under the cover of Kalahari sand, reconnaissance drill sections highlight potential to extend the mineralisation over an additional 1 km of strike.

The potential for subparallel repeat lodes at the Spanover Border and Windmill prospect areas is evident, Harmony highlighted, and drilling continues with three drill rigs.