henry: top mining tax rate would be 56.8% , page-19

The 56.8% tax rate is the NOMINAL tax rate on all "super-profits".

The 40% super-profit tax does not, however, allow for interest on borrowings, so it is effectively MORE than 40% of net profit unless a company has no borrowings at all. In my opinion, this means that a company that is highly leveraged (like FMG) will definately be paying an effective rate on "super-profits" significantly above 56.8%.