What is one of the major characteristics of mafic rocks?

• A. High levels of feldspar
• B. High silica content
• C. Low silica content
• D. Forms only in sedimentary environments

Answer: (C)

Mafic rocks are characterized by their relatively low silica content compared to other types of igneous rocks, such as felsic rocks, which have higher silica levels. This lower silica content typically results in a rock that is rich in iron and magnesium, both of which contribute to the darker color and denser nature of mafic rocks.

Mafic rocks, which include basalt and gabbro, are formed from the cooling and solidification of magma that is low in silica. This characteristic composition influences not only the mineral makeup of mafic rocks but also their formation processes, which are usually associated with volcanic activity rather than sedimentary environments. Consequently, the identification of a mafic rock as having low silica content helps in understanding its formation and the type of environments in which it can be found, which are primarily igneous rather than sedimentary. The other characteristics mentioned in the choices do not align with the fundamental nature of mafic rocks.