The process of preferentially melting certain components of a solid. Basalts are derived from varying degrees of partial melting of mantle material.
The incomplete melting of a rock composed of minerals with differing melting points. When partial melting occurs, the minerals with higher melting points remain solid while the minerals whose melting points have been reached turn to magma.
The process by which minerals with low melting points liquefy within a rock body as a result of an increase in temperature or a decrease in pressure (or both) while other minerals in the rock are still solid. If the liquid (magma) is removed before other components of the parent rock have melted, the composition of the magma can be quite different from that of the parent rock. Partial melting is believed to be important in the generation of basaltic magma from peridotite at spreading centers and in the generation of granitic magma from basaltic crust at subduction zones.
When any rock melts, some of the minerals it is made of will melt first, at lower temperatures. If this liquid then rises away from its source, its chemistry will be different from that of the rock which has 'partially melted'.
incomplete melting of a 'parent rock' to produce a molten rock (like magma) with a different chemical composition. This happens because different minerals melt at different temperatures.