au porphyry resource table

There have been a few recent posts by some of the Geos and other knowledgeable members on the importance of Cu-Au porphyry deposits. The emphasis has been on how low grades don't matter when you have high tonnage.

I thought I'd do up a table to make it simple to work out the gold resource in troy ounces when you know the tonnage and grade. Note this is gold only - I've left the copper out so it's not an Au equivalent grade.

Across the top are the gold grades in g/t and down the side are the ore tonnages (in millions of tons). I've made the steps fairly large as the table would be too big if I went up in steps of 0.02 g/t say.

I'll use the example of the imaginary rectangular block of ore beneath drill pad 2 that I drew in this thread.

Let's just round it to 280Mt contained in that block. Checking the table you can see that even at a low 0.20 g/t average Au grade, that section alone would contain more than 1.8 Moz of gold.

What will the eventual size of the mineralised orebody be I wonder? What grades will we get?

I can redo the table to show tonnages greater than 1 billion if (when) required.

I hope some of you may find it useful.