Learn on PengiAmplify Science (California) Grade 7Chapter 2: Understanding Plate Boundaries

Lesson 4: Determining the Boundary

Key Idea.

Section 1

Decoding Geologic Clues

Key Idea

Scientists act as detectives to identify plate boundaries. They cannot always see the plates moving, so they look for geologic indicators. The direction of movement defines the boundary type.

If the evidence shows new rock forming and plates separating, it is a divergent boundary. If the evidence shows subduction, trenches, or plates colliding, it is a convergent boundary.

Section 2

Synthesis of Boundary Types

Key Idea

Different boundaries result in different outcomes for the Earth's crust. Divergent boundaries result in construction (new rock added), while convergent boundaries often result in destruction (rock recycled).

By mapping these processes globally, scientists understand the cycle of Earth's surface. The rigid plates are constantly being built at one edge and destroyed at another, driven by the dynamic mantle below.

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 2: Understanding Plate Boundaries

  1. Lesson 1

    Lesson 1: The Mantle and Convection

  2. Lesson 2

    Lesson 2: Divergent Boundaries

  3. Lesson 3

    Lesson 3: Convergent Boundaries

  4. Lesson 4Current

    Lesson 4: Determining the Boundary

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

Decoding Geologic Clues

Key Idea

Scientists act as detectives to identify plate boundaries. They cannot always see the plates moving, so they look for geologic indicators. The direction of movement defines the boundary type.

If the evidence shows new rock forming and plates separating, it is a divergent boundary. If the evidence shows subduction, trenches, or plates colliding, it is a convergent boundary.

Section 2

Synthesis of Boundary Types

Key Idea

Different boundaries result in different outcomes for the Earth's crust. Divergent boundaries result in construction (new rock added), while convergent boundaries often result in destruction (rock recycled).

By mapping these processes globally, scientists understand the cycle of Earth's surface. The rigid plates are constantly being built at one edge and destroyed at another, driven by the dynamic mantle below.

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 2: Understanding Plate Boundaries

  1. Lesson 1

    Lesson 1: The Mantle and Convection

  2. Lesson 2

    Lesson 2: Divergent Boundaries

  3. Lesson 3

    Lesson 3: Convergent Boundaries

  4. Lesson 4Current

    Lesson 4: Determining the Boundary