Question

the continental crust is:
a. composed mostly of basalt.
b. formed from slowly - cooled lava.
c. made of rock 50 million years old.
d. less than 10 km thick.

Explanation:

• Option A: Oceanic crust is mostly basalt, not continental crust.
• Option B: Continental crust is formed from magma that cools slowly (intrusive igneous rocks like granite), which is a correct formation process.
• Option C: Continental crust has rocks of various ages, some much older than 50 million years.
• Option D: Continental crust is generally thicker than 10 km (average around 30 - 50 km).

Answer:

B. formed from slowly - cooled lava.