Epithermal-type deposits are small, high-grade gold and/or silver ± base metal deposits that formed shallowly in the upper crust and are frequently associated with hydrothermal fluids related to deeper emplaced, large tonnage, low-grade precious metal ± base metal porphyry deposits. Bringing the deeper emplaced deposits to surface requires processes such as erosion of overlying rocks. Consequently, epithermal systems that formed at approximately the same time as porphyry systems are often eroded.