Felsic rocks have lower melting temperatures than mafic rocks.

Felsic rocks have lower melting temperatures than mafic rocks.

• A. Lower
• B. Higher
• C. The same
• D. Variable

Answer: (A)

Melting temperature depends on rock composition: felsic rocks, being rich in silica and light-colored minerals like feldspars and quartz, begin to melt at lower temperatures than mafic rocks, which are richer in magnesium and iron-bearing minerals like olivine and pyroxene that resist melting until higher temperatures. In practical terms, partial melts of crustal, silica-rich rocks produce silicic magmas at relatively lower temperatures, while melts from mantle-derived, mafic rocks require higher temperatures to start. That’s why the statement that felsic rocks have lower melting temperatures is the best description.

Melting temperature depends on rock composition: felsic rocks, being rich in silica and light-colored minerals like feldspars and quartz, begin to melt at lower temperatures than mafic rocks, which are richer in magnesium and iron-bearing minerals like olivine and pyroxene that resist melting until higher temperatures. In practical terms, partial melts of crustal, silica-rich rocks produce silicic magmas at relatively lower temperatures, while melts from mantle-derived, mafic rocks require higher temperatures to start. That’s why the statement that felsic rocks have lower melting temperatures is the best description.