Ann: Emmie Bluff Deeps IOCG Mineralisation Additional Information, page-62

I totally agree that you can't economically mine that, it was more trying to get a feel for the quantity of Cu equivalent. Grades appear to be 2%, but my guess is that it will not be that grade throughout. I was using 0.2% to get an overall quantity. This mineral deposit appears to be horizontal and at that depth it will not be economical to dig a hole 400m deep.
Long wall mining as used in the coal industry may be an option, but then you it depends on the strength of the rock.
May be an over-reaction in share price increase, due to the issues of actually getting the minerals to the surface.