Sierra del Perdon contains an indicated resource of 41.8 million tonnes at 10.7% potassium oxide, with a further 40.3Mt at 10.5% inferred.

The resource covers an area where sylvinite and carnallite were mined between 1963 and 1996 when production ceased due to low potash prices, as well as new areas of potential exploration around the Sierra del Perdon basin.

It was compiled based on a six-hole drilling program completed in 2013 in conjunction with historical data, production reports and mapping profiles compiled by previous miners at the site.

Of the six holes, two were areas not previously mined and showed good intersection of carnallite and sylvinite, three were drilled into existing workings and achieved poor recovery, and one testing the western extent of the basin was barren.

As a result, the company outlined an exploration target for the project of 50-100Mt of sylvinite at 10-14% potassium oxide; and 100-250Mt of carnallite at 9-13%, mostly targeting areas not previously mined.

The exploration target comprises the drilling of 23 core holes, including the six already completed, over 44 square kilometres in the deeper part of the basin.

Up to five additional holes have been proposed for this year.

Highfield managing director Anthony Hall said it was encouraging for the company to be developing a second resource in Spain.

“Whilst our focus remains on the flagship Muga potash project, we are in a fantastic position to have a second project that we believe is also likely to be very compelling,” he said.

Highfield expects to have a scoping study released for Sierra del Perdon during the current quarter.

Shares in Highfield closed at $A1.62 on Thursday.