The type of mine dump that is best for metal detecting are the ones that consist of mixed sizes of rock and are located near some sort of excavation, commonly a shaft or adit. Sometimes the piles located along a trench dug by the miners can be productive as well.

Even with my favorite top-of-the-line gold detector there were several false digs. Many of the hot rocks gave a solid signal that was too much like a nugget to ignore. After trying several tests I just dug everything because it is better to be safe than leave a big, deep nugget for a more diligent gold hunter.

...these nuggets have not traveled far from the lode because the golden wire lattices would have been torn apart or flattened during weathering of rock and deposition by violent stream action.