Why is gold found at the surface?

gold mines surfaceWhy is gold found at the surface or just below?

Has the gold been formed due to the transmutation of the host material where it is found?

Why is gold found in mountains and hills if it has to be produced deep underground?

Muruntau. This mining complex, located in Uzbekistan and consisting of open-pit mine and heap leach operations, is believed to produce about 2.6 million ounces of gold in 2014. Huge open-pit mine has following dimensions: 3.35 km – length, 2.5 km – width and 560 m – depth.

Yanacocha’s operations are situated between 3,500 and 4,100 meters above sea level
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