Final answer:
Mafic magma, which is richer in Ca, Mg, and Fe, has a lower viscosity allowing it to flow more easily than felsic magma.
Step-by-step explanation:
If a body of magma becomes more mafic (richer in Ca, Mg, and Fe), its viscosity will decrease.
Mafic magma contains more magnesium and iron, which tend to have simpler structures and lower silica contents compared to felsic magmas, resulting in a lower viscosity. Mafic magmas, being less viscous, can flow more easily.