"The revised resource estimate (based on a 12g/t cut-off) will now be applied to develop new pit designs, mine schedule and ore reserve calculation."
The JORC estimate referred to is
Indicated 21.7mt @ 55.3g/t for 38.6Moz
Translating this from prior JORC updates: 11.3mt of it is @ 78.7g/t 5.3mt of it is @ 38.2g/t 5.1mt of it is @ 19.5g/t
The boundary pit is the low grade portion (sub 40g/t). From my calcs, the milled grade has so far averaged 36.5g/t and oct figures range between 44g/t and 50g/t. If the mill was only fed by ore from the boundary pit then the current figures would make sense; except the company reported that they've mined at an average 72g/t (and they'd know this by cross-referencing the blocks they've physically mined with the blocks in the resource model - each block will have an average grade and a percentage error and confidence level, ie. I'm 90% confident that the grade of this block will be 65 to 79g/t). It's quite rare that multiple blocks will fall outside this grade range, ie. 1/10 * 1/10 *1/10 and you start looking at a 1 in 1,000 type event.
Personally, I think it's a management/communication issue rather than a resource issue. It tends to happen when investors start approving bonuses and 20%pa salary increases before the results are in... you know, like when I get $100k bonus, I forget about my day job of crunching numbers and start planning on whether I want a serve of Thai or a piece of Russian to entertain me for the evening ;)
CCU Price at posting:
30.6¢ Sentiment: Hold Disclosure: Not Held