Where in the earths crust(lithosphere) is gold found?

Question

Where in the earths crust(lithosphere) is gold found?

Answer 1

Part of gold's high value is due to its unpredictability.  Most in place gold mines are in quartz veins as the result of near surface and middle depth hydrothermal vein emplacements.  Most placer gold (gold eroded from the original emplacement and carried and concentrated in rivers beds and banks) comes from these veins.

But it is hard to predict where these veins can be found, many do not break to surface.  And they can be in any surrounding rock.  Gold is mined within all rock types.

In the 1990's an erupting volcano in Ecuador was calculated to be putting out up to 2 kilos of gold a day but with so much dilution it was economically impossible to mine profitably.