Overview
This lesson explains the processes and landforms that occur along divergent and transform plate boundaries, focusing on how these boundaries shape the Earth's surface.
Plate Boundaries Overview
- Plate boundaries are zones where two tectonic plates meet and interact.
- The three main types of plate boundaries are convergent, divergent, and transform.
Divergent Plate Boundaries
- Divergent boundaries occur where two plates move away from each other.
- This movement creates a gap that allows magma to rise and solidify, forming new crust.
- Mid-ocean ridges, such as the Mid-Atlantic Ridge, are major landforms at divergent boundaries.
- Rift valleys can form on continents where plates are diverging, such as the East African Rift.
- Sea-floor spreading is the process of new oceanic crust being created at divergent boundaries.
Transform Plate Boundaries
- Transform boundaries occur where two plates slide horizontally past each other.
- No new crust is formed or destroyed at transform boundaries.
- The San Andreas Fault in California is a major example of a transform boundary.
- Earthquakes are common along transform boundaries due to the build-up and sudden release of stress.
Processes at Plate Boundaries
- Movement along divergent boundaries results in the formation of oceanic ridges and rift valleys.
- Movement along transform boundaries results primarily in earthquakes rather than mountain or volcano formation.
Key Terms & Definitions
- Divergent boundary — a plate boundary where two tectonic plates move apart.
- Transform boundary — a plate boundary where two tectonic plates slide past each other horizontally.
- Mid-ocean ridge — an underwater mountain range formed at a divergent boundary.
- Sea-floor spreading — the process of new oceanic crust forming at divergent boundaries.
- Rift valley — a deep valley formed on land by the pulling apart of a continental plate.
- Earthquake — a sudden shaking of the ground caused by movement along faults, common at transform boundaries.
Action Items / Next Steps
- Review the locations and examples of major divergent and transform boundaries on a world map.
- Prepare for a quiz on plate boundary processes and the landforms they create.
- Read next lesson on convergent boundaries for further understanding.