Question

which statement describes how the mantle is similar to earths oceanic crust?
○ it is composed mostly of basalt.
○ it consists primarily of molten rock.
○ it has varying degrees of thickness.
○ it is divided into two layers.

Explanation:

1. Analyze each option:

• Option 1: Oceanic crust is composed mostly of basalt, but the mantle is not (mantle has different compositions like peridotite in the upper mantle). Eliminate.
• Option 2: The mantle has a significant portion of molten or semi - molten rock (magma in parts), and oceanic crust is solid. Eliminate.
• Option 3: Oceanic crust has varying thickness (usually thinner than continental crust, but still varies), and the mantle also has varying thickness (upper and lower mantle have different thicknesses, and the mantle as a whole has different thickness compared to other layers). This is a similarity.
• Option 4: The mantle is divided into upper and lower mantle (two main layers), but the oceanic crust is a single - layer - like structure (not divided into two layers in the same sense). Eliminate.

Answer:

It has varying degrees of thickness.