Multiple choice

The oceanic crust mainly consists of ____.

  1. Silica & Alumina

  2. Silica & Magnesium

  3. Nickel and Iron

  4. Argon & Nitrogen

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The oceanic crust is relatively thin and is mainly composed of silica and magnesium. This composition leads to it being commonly referred to as 'sima' (Si for silica and Ma for magnesium). In contrast, the continental crust is rich in silica and alumina.