What is a consequence of partial melting?

The process of partial melting occurs when only a fraction of a solid rock melts, often leading to a change in the mineral composition of the remaining solid material. As certain minerals reach their melting point and turn into magma while others do not, this can result in the formation of new minerals. The minerals that form from this process can differ significantly from those in the original rock, depending on the composition of the melt and the temperatures involved.

This new mineral formation occurs because the chemistry of the melt differs from that of the solid phase. Elements and compounds that were initially locked in solid minerals may combine in different ways as they melt and recrystallize. This contributes to the diversity of rock types and mineral assemblages observed in geological formations.

The other options do not align with the outcomes of partial melting. Complete solidification refers to the process of a melt solidifying entirely, which does not apply to partial melting, as this process involves only a part of the rock melting and not a complete transition to solid. The construction of metamorphic rocks relates to the alteration of pre-existing rocks under pressure and temperature without melting, demonstrating a different geological process. Lastly, while partial melting may lead to different compositions, it typically does not result in increased purity of the original rock;