What is flux melting?

Flux melting refers to the process where the addition of water or other fluids lowers the melting temperature of rocks, leading to their melting. This occurs primarily in subduction zones, where an oceanic plate is forced beneath a continental plate, causing water and other volatiles to be released from the subducting plate. This release of fluids enhances the melting of the surrounding mantle or crustal rocks, facilitating the generation of magma.

This concept is important in understanding how certain geological features form, such as volcanoes, in regions that are tectonically active. The presence of these fluids is crucial because they facilitate the melting of materials that otherwise would not melt at the temperatures and pressures present. In contrast, melting due to increased pressure, surface environments, or volcanic activity alone does not specifically involve the augmentation of melting through the addition of fluids, which differentiates flux melting from other melting processes.