Which term refers to a light-colored igneous rock due to high silica and feldspar content?

Which term refers to a light-colored igneous rock due to high silica and feldspar content?

• A. Felsic
• B. Mafic
• C. Ultramafic
• D. Intermediate

Answer: (A)

Felsic rocks are the ones described. They are light-colored because they are rich in silica and light-colored minerals, especially feldspar and quartz. This combination gives them a pale appearance and a relatively low iron and magnesium content. In contrast, mafic and ultramafic rocks are darker because they contain more iron and magnesium-rich minerals, and intermediate rocks fall somewhere in between. So the term that best fits a light-colored igneous rock with high silica and feldspar (and quartz) content is felsic.

Felsic rocks are the ones described. They are light-colored because they are rich in silica and light-colored minerals, especially feldspar and quartz. This combination gives them a pale appearance and a relatively low iron and magnesium content. In contrast, mafic and ultramafic rocks are darker because they contain more iron and magnesium-rich minerals, and intermediate rocks fall somewhere in between. So the term that best fits a light-colored igneous rock with high silica and feldspar (and quartz) content is felsic.