Which term describes the oceanic crust that is rich in magnesium and silica?

Which term describes the oceanic crust that is rich in magnesium and silica?

• A. Sial
• B. Sima
• C. Basalt
• D. Granite

Answer: (B)

The oceanic crust is best described by the term that refers to a composition of silica with magnesium. This combination points to the Sima layer, which is the denser, magnesium-silicate part of the crust that forms most of the ocean floor. The rocks here are basalt, a basaltic rock typical of this layer. In contrast, Sial describes silica with aluminium and is associated with lighter continental crust, while granite is a continental rock and basalt is a common oceanic rock, not the name for the crust itself. So the correct term is Sima.

The oceanic crust is best described by the term that refers to a composition of silica with magnesium. This combination points to the Sima layer, which is the denser, magnesium-silicate part of the crust that forms most of the ocean floor. The rocks here are basalt, a basaltic rock typical of this layer. In contrast, Sial describes silica with aluminium and is associated with lighter continental crust, while granite is a continental rock and basalt is a common oceanic rock, not the name for the crust itself. So the correct term is Sima.