who else has these grades?, page-4

These sort of grades are not totally uncommon in rich underground load or reef systems. The saddle reefs at Bendigo can go into the 1000s gt over widths up to a metre-but once you dilute the figures back to a true width, and take into account continuity from one spot in the mine to the next along strike, the grades will eventually drop back.
It is like a hot spot, or "jewellery box".
The biggest issue can be security-miners love keeping the best samples and at these sort of grades the gold will be quite visible.
Old mining maxim I told earlier-"Tis a poor sphincter that cant hold an ounce of gold"-source, old timers at the A1 Mine in Victoria!