Mantle

Definition

The mantle is the thick, solid layer of rock between Earth's crust and core, making up about 84% of Earth's volume. It plays a crucial role in plate tectonics and the heat transfer that drives geological activity.

5 Must Know Facts For Your Next Test

1. The mantle extends from approximately 35 kilometers below the Earth's surface to about 2,900 kilometers deep.
2. It consists mainly of silicate minerals rich in magnesium and iron.
3. Convection currents within the mantle are responsible for the movement of tectonic plates.
4. The mantle can be divided into the upper mantle and the lower mantle, with distinct physical properties.
5. Temperatures in the mantle range from about 500°C near the crust to over 4,000°C closer to the core.

Review Questions

• What is the primary composition of Earth's mantle?
• How do convection currents in the mantle affect tectonic plates?
• What are the temperature ranges found within Earth's mantle?

Related terms

Crust:

The outermost layer of Earth, composed primarily of basalt and granite.

Core:

The innermost part of Earth, consisting mainly of iron and nickel.

Plate Tectonics:

A scientific theory describing the large-scale motion of seven large plates and numerous smaller plates that make up Earth's lithosphere.