A "subduction boundary" is not a type of plate boundary.
1. **Divergent Boundary**: This is where two tectonic plates move away from each other. Magma rises from beneath the Earth's crust, creating new crust as it cools and solidifies. Divergent boundaries often occur along mid-ocean ridges, where new oceanic crust is formed.
2. **Convergent Boundary**: This is where two tectonic plates move toward each other. Depending on the type of crust involved, three types of convergent boundaries can occur:
- Oceanic-Oceanic Convergence: One oceanic plate subducts beneath another, forming deep ocean trenches and volcanic arcs.
- Oceanic-Continental Convergence: Oceanic plate subducts beneath a continental plate, forming volcanic arcs, trenches, and mountain ranges.
- Continental-Continental Convergence: When two continental plates collide, they crumple and fold, creating vast mountain ranges.
3. **Transform Boundary**: This is where two tectonic plates slide past each other horizontally. The movement can be smooth, resulting in little to no seismic activity, or it can be j3rky, causing earthquakes. The famous San Andreas Fault in California is an example of a transform boundary.
4. **Subduction Boundary**: This is not a recognized type of plate boundary. It's a process that occurs at convergent boundaries where one tectonic plate is forced beneath another into the mantle. The region where this occurs is called a subduction zone. It's an essential mechanism for the recycling of the Earth's crust.
So, "subduction boundary" is not a distinct type of plate boundary; rather, it's a process that occurs at convergent boundaries.
