Ann: Up to 10.85% Copper plus Gold intersected at Horse Well, page-70

Very silly and naive to say that mining 300m underground is no different to mining 1100m underground, for large low-grade block cave operations you need to get to the bottom and mine up, think of the capital costs of a 1 in 7 spiral decline to 1100m depth, thats 7700m distance of 5x5m spiral decline at approx $6000 without pricing in any portal/vent/lateral development or services we are talking an upfront capital cost of A$9.2M just to get down to 1100m depth, or you could sink a vertical haulage shaft to 1100m for a cost of approx A$400K per vertical meter (Oz Minerals Wira shaft to 1290m was a A$600M capital cost).

You are right - they aren't after the 80cm of 10% Cu, but the volumes of the low grade intervals need to add up to something truly enormous to justify block caving 0.5%-0.7% Cu ore, have a look at the capital costs and volumes of OZL's Carrapateena and Prominent Hill and ask yourself if Prominent Hill would have been a goer without the initial open-cut operation.