Compared with continental crust, oceanic crust is

Compared with continental crust, oceanic crust is

• A. Thinner and more dense
• B. Thicker and more dense
• C. Thinner and less dense
• D. Thicker and less dense

Answer: (A)

The main idea here is how crustal composition affects thickness and density. Oceanic crust is formed from basaltic, mafic rocks that are denser than the granitic, felsic rocks making up continental crust. Because of this, oceanic crust sits thinner but heavier, while continental crust is thicker but lighter.

In numbers, oceanic crust is about 5–10 km thick and has a density around 3.0 g/cm3, whereas continental crust is roughly 35–70 km thick with a density near 2.7 g/cm3. This combination means oceanic crust is thinner and more dense than continental crust.

So, the statement that best matches reality is that oceanic crust is thinner and more dense. The other possibilities would imply oceanic crust is either thicker or less dense, which isn’t the case.