In this mountain building process, different rocks of all types are often buried and forced under a continent where they often experience very high pressures and temperatures. These high temperatures and pressures often result in chemical reactions that rearrange the rock's mineral constituents. This hypothesis suggests that as rocks are undergoing this metamorphism, ore metals are dissolved in water that was contained in the original rocks. Metamorphism causes the solution to be expelled from the rocks and move to the surface. Another type of gold deposit is a placer deposit.
Placer deposits come from preexisting lode deposits that are exposed at the surface of the earth.
As these lode deposits are exposed and weather, the gold is released from the surrounding rock and exposed veins are transported by rivers in the form of dust or flakes. Because of gold's high specific gravity, it moves downstream usually in times of high water when everything that rests on the stream bottom is moved downstream. When the stream slows gold will collect in pockets of sand and gravel bars. Image taken from The South Carolina Gold Museum Gallery . Today there are many places throughout the world where you can still pan for gold.