What is the term for the phenomenon that occurs when only some parts of a rock melt?

The term that describes the phenomenon where only certain portions of a rock melt is known as partial melting. This process is significant in geology, particularly in the formation of igneous rocks and the differentiation of minerals within a magma body.

Partial melting occurs when the temperature and pressure conditions are such that some minerals in the rock reach their melting points while others remain solid. This typically happens in the Earth's mantle and crust under specific thermal conditions. The minerals that melt first have lower melting points compared to those that remain solid, which leads to a composition of the resulting magma being different from that of the original rock.

Understanding partial melting is critical for various applications in mining and geology, including the exploration and extraction of minerals, as it can affect the availability of ore deposits and influence the geochemical characteristics of the rocks involved.