To be honest I was shocked when I red about the impairment. But...

To be honest I was shocked when I red about the impairment. But after reading the pages 35 - 41 several times I felt a little bit better, although I am of the opinion that management should have understood that these kind of adjustment would be sensitive and they should have explained the impairment by letting us know their calculations, not only the change in assumptions. But after reading the policies on depreciation/amortisation an impairment I found the following:

Deprec/Amortisation is based on proven reserves. As we all can read these reserves dropped from 820.000 to 590.000,- due to new standards (2012 level).This explains the large increase in the annual report of almost AUD 15 mln.
Impairment of AUD 259 mln.: an amount of AUD 54 mln is on the account of the lower expected price of gold. Next to that a 1% increase in discount rate is another AUD 5 mln. (why it went upI would like to know), but what I don't know is the effect of the lower proven reserves in combination with a higher production level, through a lower remaining life of the mine " forced" the company not only to higher levels of annual depreciation and amortization ( which we would not see in this year because of the hugh impairment) but also to a huge impairment of the built up assets in the past. Therefore it is necessary that management explain their calculations. If it is only the framework that is changed, which leads to the huge impairment, I will look to the future with happiness, because today's loss is the futures profit. But I would like to know if this is indeed the case. I truly believe management missed it out completely by not letting us know how they see this impairment exercise. How do they see the future? I am hoping for an explanation from the management by issuing a clarifying press release