Overview
This lesson explains the processes and landforms that form at convergent plate boundaries, focusing on what happens when tectonic plates collide and the resulting geological features.
Plate Boundaries Review
- Earth's lithosphere is divided into tectonic plates that move due to mantle convection.
- Three main types of plate boundaries: convergent, divergent, and transform.
Convergent Plate Boundaries
- Convergent boundaries occur when two plates move toward each other and collide.
- There are three types of convergent boundaries: oceanic-oceanic, oceanic-continental, and continental-continental.
Processes at Convergent Boundaries
- Subduction occurs when a denser plate sinks beneath a less dense plate, forming a subduction zone.
- The descending plate melts and may form magma, leading to volcanic activity.
Landforms Created by Convergence
- Oceanic-oceanic convergence forms volcanic island arcs (e.g., Japan, Philippines).
- Oceanic-continental convergence creates continental volcanic arcs and trench systems (e.g., Andes Mountains).
- Continental-continental convergence produces large mountain ranges (e.g., Himalayas).
Earthquakes and Volcanic Activity
- Earthquakes often occur at subduction zones due to the movement of plates.
- Volcanic eruptions are common where subducted plates melt and magma rises to the surface.
Experiment Demonstrations
- Experiments can model plate movement using objects like clay or foam to mimic plates colliding.
- These models help visualize uplift, subduction, and mountain formation.
Key Terms & Definitions
- Convergent Boundary — a plate boundary where two tectonic plates collide.
- Subduction Zone — region where one plate slides beneath another into the mantle.
- Volcanic Island Arc — a chain of volcanic islands formed above a subducting plate.
- Trench — a deep depression in the ocean floor formed at a subduction zone.
- Continental Volcanic Arc — a range of volcanoes formed on a continent above a subduction zone.
- Mountain Range — a series of mountains formed from the collision of continental plates.
Action Items / Next Steps
- Review notes about the characteristics of each type of convergent boundary.
- Prepare for a quiz on landforms and processes at plate boundaries.
- Try a simple plate boundary model experiment at home if materials are available.