Based on drilling and two-dimensional seismic survey data, it said the Kola and Dougou extension deposits had the potential to be extended by 1.5-1.9 billion tonnes of sylvinite with an average grade of 34-37% potassium chloride, although there had not been enough exploration to determine a mineral resource estimate.

The project has an existing sylvinite resource of 1.08Bt with an average grade of 35.5% potassium chloride.

Looking at the deposits separately, Kola South had the potential to be extended by 95-175 million tonnes at an average grade of 34-42% potassium chloride, while Dougou Extension North had the potential of a 320-600Mt upgrade at an average grade of 30-38% potassium chloride.

Kore said the numbers were conceptual in nature and an approximation and it was also not sure whether further exploration would result in a mineral resource estimate.

The two targets, located immediately adjacent to the existing resource, had been identified as part of the work programme to improve Kore's understanding of the potential scale and the strategic opportunities presented by multiple potash occurrences in the project area.

The news had no positive impact on Kore's stock, with its shares down 2.86% in London Wednesday to 8.5p (US10.88c).