Ann: Strong Mineralisation in Manto & Callancocha Structure, page-61

I'm no expert but I can see a few potential floors in your calculations.

Firstly I'm no geo but an SG of 4 looks high to me, my understanding is that an SG of 2-3 is more common, so that could knock 33-50% off if that's the case.

Then for your 15m width I think you may be using down hole width (intersect width) not true width, if that's the case then with a drill angle of 45 degrees you can knock a third off that.

Then the big question is the 2000m x 800m x 15m measurement for the manto. All I can see with those measurements in recent anns is: "The manto is recorded along the perimeter of Humaspunco Hill, which covers an area of about 1.2 kilometres by 800 metres. The Callancocha Structure is 800 metres long at Humaspunco". Which I take as a measurement of the whole area not the manto itself, although I may well have missed something. Also if we say 2km is the length and 10m is the true width (as shown by drilling) then the third dimension you use of 800m would have to be depth, which I don't think is the case.

So although this manto looks big and encouraging I think the basis for some of your calculations could be a little flawed unfortunately.

Happy to be corrected.