The oceanic crust of the earth mainly consists of ______.

The oceanic crust of the Earth is mainly made up of mafic rocks, silica, and magnesium, and is also known as sima.

• Mafic rocksThese rocks include basalt, gabbro, and troctolite, and are rich in iron, calcium, and magnesium.
• SilicaThis mineral makes up about 50% of the oceanic crust. It's known for its high melting point, hardness, and chemical stability.
• MagnesiumThis lightweight metal makes up about 35% of the oceanic crust. It's known for its high strength-to-weight ratio and its ability to resist corrosion.