Underground Gold Resources versus Oxide ProportionThis is a difficult nut to crack.
We have plenty of open pit oxide mines, so their productivity can be estimated.
All oxides have as their source, the eroded portion of basement sulphide rocks which are mostly virginal and of higher grade.
Further, almost every basement goes as deep and even deeper than 500 meters but few of these have been mined to that depth.
WGX has and so has Barrick at its world class Kimbali mine which is ranked in the 10 largest producing mines in the world.
Best that I can arrive at is that the underground sulphide source rock contains at least 3 times the gold resources as its shallow open pit oxides.
This can easily be inferred from the higher grades of underground gold and the much greater depths ( over 1000 m) of the basement lode versus the shallow maximum depth ...100 m..of oxide pits.
Thats why the greatest gold mines in the world are underground..