more dodgy reporting mr hunt?, page-16

Just a comment about highly selective digging (say 1m wide). In my experience, in supergene, and highly weathered ground, this is much harder than it seems on paper, unless there is a very clear visual element to the ore. Which typically supergene ore will not have - the supergene process, whilst upgrading the primary gold grades, will also move the gold away from veins and faults. By trying to be too selective you can actually end up missing the ore and just mining the waste.
The issue then is at the resource/reserve modelling stage - it needs to be modelled at a "practical mining width". The practical mining width is a function of the size of mining gear, and bench height and the characteristics of the orebody. If any of these change, then the reserve may need to be reviewed, as it will affect the grade.