John Wesley Powell put forward the idea of base level, which refers to
A) an imagined surface that extends inland from sea level, and is inclined gently upward.
B) a level below which a stream cannot erode its valley.
C) an evolutionary cycle of landscape development.
D) flat plateaus.
E) Both A and B are correct.

Question

Quizplus · Accepted Answer

Base level is an imagined surface that extends inland from sea level, and is inclined gently upward. It is also the level below which a stream cannot erode its valley.

John Wesley Powell Put Forward the Idea of Base Level