Question

Fluid-fluxed melting is the second-most common melting mechanism that generates molten rock (magma).  Which of the following best describes this partial melting process?

Group of answer choices

Water released by metamorphic reactions from a subducting plate lowers the melting temperature of the upper mantle above the subduction zone causing partial melting of this upper mantle.

Intrusion of basaltic magma into the continental crust partially melts the continental crust which has a much lower melting temperature than basalt

Outer core injects into the upper mantle, heating it and causing it to melt.

Solid mantle rises and partially melts as pressure decreases

Rock is buried and melts as pressure increases

Answer 1

The outer core injects (vapor phases) into the upper mantle, heating it and causing it to melt. This is the second most common melting mechanism that generates magma. The decompression melting in which the water released by the subducting slab's metamorphic reaction lowers the upper mantle's melting temperature above the subduction zone, causing partial melting of the upper mantle most dominant process for magma generation. It causes the maximum possible partial melting than other processes.