Here are some examples of existing Copper Gold Porphyry mines in...

Here are some examples of existing Copper Gold Porphyry mines in Australia:

Take a look at the grade of gold they are digging out of the Northparkes open cut mine in NSW. 0.5ppm which works out to how many grams of gold per tonne of rock they dig out? Is it 0.05%? (I don't know how to do the maths).

* Cadia-Ridgeway Mine, New South Wales, copper-gold deposit mined by open pit and block caving.
** Northparkes copper porphyry deposit, New South Wales, with 63 million tonnes at 1.1% Cu and 0.5 ppm Au.**
* Boddington, Western Australia, one of the largest Archaean gold porphyry deposits in Australia

Northparkes is a copper and gold mine located in central New South Wales, Australia, approximately 27 kilometers north-northwest of the town of Parkes.

[1] The mine was originally started in 1994 using open pit mining, with underground mining using the block caving method starting in 1997. The mine has an operational capacity to produce five million tonnes of ore per year, containing roughly 60,000 tonnes of copper and 50,000 ounces of gold. Economic viability of the mine is projected to extend at least to the year 2015.

[2] The mine is 80% owned by the Rio Tinto Group,[2] with the remaining 20% owned by the Sumitomo Group.[1]