RE:RE:drilling deeper Meaning, if I understand your comment, there has been a much greater amount of erosion on the top of Queensway than in Fosterville. This translates to the higher grade ore being closer to surface as the top level has been eroded and dispersed.
This is a benefit as the cost of extraction of the higher grade is less costly in theory. Not really, as after the shaft has been dug to a greater depth the cost of mining horizontally does not vary greatly with depth. Yes the original cost is higher as developing a shaft is costly, but on the overall not a factor.