Which part of the Earth is made up mainly of silica and magnesium, and is therefore called ‘sima’?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Oceanic crust
The crust under the oceans is made up mainly of silica (si) and magnesium (ma), so it is called sima. The continental crust is made of silica and alumina (sial).