How is partial melting related to fractional crystallization?

Answer 1

Partial melting occurs in rocks because the different minerals that compose rocks have different melting points. For example, felsic minerals (e.g. quartz and feldspar) melt at around 700 degrees Celsius while mafic minerals (e.g. pyroxene and olivine) melt at around 1200 degrees Celsius. Therefore, felsic minerals will melt first leaving the mafic minerals solid.

Fractional crystallization occurs when minerals from a magma cool and crystallize out of the magma. The first crystals to melt in partial melting will be the first minerals to crystallize out when the magma begins to cool. Therefore, mafic minerals will crystallize first, followed by felsic minerals.

Both partial melting and fractional crystallisation tend to produce a more felsic magma than their source rocks.

The difference is simply that they are the reverse of one another, heat it up, cool it down. Things that melt first solidify last and separate from one another.

Answer 2

Fractional crystallization is defined as the process of separating the components of a solution on the basis of their different solubilities, by means of evaporating the solution until the least soluble component crystallizes out. If you have a solidified solution of different substances, when cooled slowly the substance with the highest melting temperature will be the first to start melting, and the one with the lowest melting temperature will be the last. The two processes are the opposite of each other in direction.

Answer 3

Fractional crystallization (fractionation) is that process of magmatic differentiation that accompanies the failure of early-forming crystals to react to the melt that remains. The process of fractional crystallization is responsible for the bulk of differentiation that is occurs in igneous rocks.