These measure the “quality” of the project.
Tier 1 deposits are “Company making” mines. They are large, long life and low cost.
Using long run commodity prices it generates >$300-600m pa of revenue (i.e. >200 kt pa Cu or >800 kt pa Zn+Pb or >5kt pa of U3O8 or >250 koz pa Au) for >20 years and is in the bottom quartile of the cost curve. It has very robust economics and will be developed irrespective of where we currently are in the business cycle and whether the deposit has been fully drilled out. The resource is of a size/quality that it creates multiple opportunities for expansion.
It is expected that project’s economics will easily exceed the Company’s Cost of Capital + Country Risk Premium by at least 5 percentage-points … i.e. achieve a >12% IRR after-tax in low-risk jurisdiction such as Australia or Canada. This will impact on capital-intensity of the project.
Olympic Dam, Broken Hill and Cadia East are examples of a Tier-1 deposit.
As at Jan 2013, Tier 1 deposits have a risk-adjusted NPV at the Decision-to-Build Stage of >US$1000m. As a first-pass guess, for modelling purposes, the weighted average value of a Tier 1 deposit is notionally set at ~$2000m.
