That's right about mining tortoise but these are all such big multinational companies that they will just go and mine in Brazil or wherever taxation considerations are more favourable.
Then the smaller companies will come in here, start mining and presumably not have to pay the supertax as they won't yet be making superprofits.
There are lots of bits I'm not clear on though, like why can't high profits be offset against loss making ventures/areas of investigation/infrastructure projetcs etc.
I would just think there is a better way than saying "we are taking 40% of your extra profit" - I would have thought they could consult and say X% has to go to supporting local infrastructure, X% on research and development etc.
But I only know what I see on Lateline and in the paper, maybe they already have to do this.
All I see is that the mining companies have fuckloads of money and surely some of it could be pumped back into the economy, without pissing the companies off so much that they up and leave?