Plate Boundaries Quick Notes

Convergent Boundaries

• Movement: Plates move toward each other.

• Subtypes:

  • Oceanic–Continental: Oceanic plate subducts under continental plate; results: trenches, volcanic arcs, earthquakes; examples: Andes Mountains, Mariana Trench.

  • Oceanic–Oceanic: One oceanic plate subducts under another; results: island arcs, trenches, earthquakes; examples: Philippine Trench, Japan.

  • Continental–Continental: No subduction; results: mountain formation; example: Himalayas.

Divergent Boundaries

• Movement: Plates move away from each other.

• Processes: Magma rises to form new crust; creation of mid-ocean ridges and rift valleys.

• Outcomes: Volcanic activity; mid-ocean ridges; Rift valleys.

• Examples: Mid-Atlantic Ridge (underwater), East African Rift Valley (land).

Transform Boundaries

• Movement: Plates slide past each other horizontally.

• Outcomes: Faulting and earthquakes; crust is neither created nor destroyed.

• Example: San Andreas Fault (California, USA).

Quick Concepts and Landforms

• Key ideas: Subduction zones create trenches and volcanic arcs; divergent zones create mid-ocean ridges and rift valleys; transform zones cause earthquakes without crust creation/destruction.

• Landforms: trenches, volcanic arcs, island arcs, mid-ocean ridges, rift valleys, mountains.

What to Remember (Process Drivers)

• Mantle convection drives plate movement.

• Plate tectonics explains how Earth’s lithosphere moves and shapes landforms.

Quick Checks (Essentials)

• Convergent boundaries: movement toward each other.

• Divergent boundaries: sea-floor spreading occurs.

• Oceanic–Continental convergence forms a trench and volcanism/arcs.

• Himalayas form from Continental–Continental collision.

• Earthquakes can occur at all boundary types.

• Continental collision yields mountains.

• Oceanic–Oceanic convergence forms island arcs.

• Mid-ocean ridges form at divergent boundaries.

• East African Rift Valley is a divergent boundary example.

• San Andreas Fault is a transform boundary.

• Mariana Trench formed by Oceanic–Continental subduction.

• Philippines Trench formed by Oceanic–Oceanic convergence.

• Rift valleys are typical of divergent boundaries.

• Subduction-related processes cause volcanism in convergent zones.

• Oceanic subduction occurs under continental in oceanic–continental convergence.

• Transform boundaries typically do not form volcanoes.

• Earthquakes can occur at all boundary types.

• San Andreas Fault is a transform fault.

• Convection moves magma to create new crust.

• Volcanoes can form where oceanic–oceanic or oceanic–continental plates collide.

Lesson Essentials (What I Need to Know)

• Earth’s lithosphere is dynamic due to plate tectonics.

• Three major boundary types: convergent, divergent, transform.

• Movements at boundaries create landforms and earthquakes.

Post-Lesson Quick Reference

• Convergent: toward; subtypes and outcomes as above.

• Divergent: away; ridge/rift formation; new crust.

• Transform: slide past; earthquakes; no crust creation/destruction.

What I Can Do (Performance Task)

• Output: Mini Poster or Infographic

• Title: "Understanding Plate Boundaries".

• Include:

  • A labeled diagram of each plate boundary

  • Brief movement explanation for each boundary

  • One real-world example per boundary

  • One fun fact or trivia per boundary type

• Suggested Materials: short bond paper or recycled cardboard, colored pens or pencils, Internet (optional for research).