How much resource are they sitting on?

From the Prospectus

The Independent Geologist’s Report has been revised to include a cautionary statement at the beginning of the report, and confirmation that the report does not contain opinions of the author on production targets or JORC compliant reserves or resources; 
The Company advises investors that these reports should not be relied upon for the purposes of making an assessment about the assets and liabilities, financial position and prospects of the Company.
No attempt is made to evaluate the tonnage potential for hardrock magnetite at Yerbas Buenas. Only two holes have been drilled into this mineralisation, and insufficient data is available to allow resource estimation.
Such a programme would take a minimum of 6 months and cost between $0.4m and $3m depending on the number of targets tested, the density of drilling required and the vertical depths drilled.