Question: igneous rock

Answer: formed from the crystallization of magma

Question: lava

Answer: magma that flows out onto the Earth’s surface

Question: extrusive rocks

Answer: fine-grained igneous rocks that cool quickly on Earth’s surface

Question: intrusive rocks

Answer: coarse-grained rocks that cool slowly beneath Erath’s surface

Question: partial melting*

Answer: the process whereby some minerals melt at low temperatures while other minerals remain solid

Question: fractional crystallization*

Answer: the process wherein different minerals form at different temperatures

Question: Bowen’s reaction series

Answer: sequential, predictable, dual-branched pattern in which minerals crystallize from cooling magma

Question: felsic rocks

Answer: light-colored rocks that have high silica content and contain quartz and the feldspars orthoclase and plagioclase. Granite is an example.

Question: mafic rocks

Answer: dark-colored rocks that have low silica content and are rich in iron and magnesium. Gabbro is an example. Also contains moderate amounts of biotite, amphibole, and pyroxene.

Question: ultramafic*

Answer: igneous rocks with low silica content and very high levels of magnesium and iron.