Which term refers to the rigid outer layer consisting of the uppermost mantle and the crust?

Which term refers to the rigid outer layer consisting of the uppermost mantle and the crust?

• A. Asthenosphere
• B. Lithosphere
• C. Mantle
• D. Core

Answer: (B)

The rigid outer shell that includes both the crust and the uppermost part of the mantle is the lithosphere. This layer behaves as a strong, stiff shell, which lets tectonic plates move as cohesive units on top of the weaker, more ductile layer beneath it—the asthenosphere. The crust forms the surface you walk on, while the upper mantle adds to the rigid stability of this shell. Below the lithosphere lies the rest of the mantle, and much deeper is the core. So the term for this rigid outer layer is lithosphere.

The rigid outer shell that includes both the crust and the uppermost part of the mantle is the lithosphere. This layer behaves as a strong, stiff shell, which lets tectonic plates move as cohesive units on top of the weaker, more ductile layer beneath it—the asthenosphere. The crust forms the surface you walk on, while the upper mantle adds to the rigid stability of this shell. Below the lithosphere lies the rest of the mantle, and much deeper is the core. So the term for this rigid outer layer is lithosphere.