Due to fractional crystallization and assimilation of surrounding host rock,most magmas that rise slowly through the crust evolve chemically to become ____________.
A) more felsic
B) more mafic
C) dominated by nonsilicate minerals

Question

Quizplus · Accepted Answer

Fractional crystallization is the process by which minerals crystallize and separate from the magma as it cools. This process removes the more mafic minerals (rich in iron and magnesium) from the magma, leaving it enriched in felsic (rich in silica) minerals. Assimilation of surrounding host rock can also change the composition of the magma towards more felsic, as the host rock may have more silica-rich minerals. Therefore, most magmas that rise slowly through the crust evolve chemically to become more felsic.

Due to Fractional Crystallization and Assimilation of Surrounding Host Rock,most