Ore Genesis

Ore genesis covers the theories that explain how the various types of mineral deposit form within the Earth's crust, so the explanation differs with the mineral or commodity examined. Most theories rest on three components: a source from which metal is liberated, a transport route that carries metal-bearing fluids or solid minerals into place, and a trap that concentrates the metal into mineable ore. The biggest deposits form when the source is large, the transport mechanism is efficient and the trap is active at the right time. Endogenous processes include magmatic processes such as fractional crystallization and liquid immiscibility, and hydrothermal processes driven by water moving through the crust, often as a consequence of magmatic intrusion or tectonic upheaval.