dj mgx 1h net profit doubles to a$140 million, page-15

Az. Did you mean mining below sealevel? Aztec Res on Koolan Is (before MGX TO) borrowed Portman's expertise on Cockatoo Is in building seawalls. As the ore price went up the schemes got larger to cut out lower. If you mean underground mining undersea (between the islands) then there is the problem that the ore body is not that far under the sea floor. In principle they could also try underground mining from within Main Pit as the ore body continues to dip down. MGX seem to be happier to move increasing depths of waste overlying the ore body and keeping it open pit for large scale purposes. This waste is presently being used in constructing the seawall which is now further out than the original design making more ore accessible. It would have been a difficult decision to determine the optimum position of the seawall w.r.t. costs and returns.

Juke