Earth and Space Science / Unit 3: Plate Tectonics
3.6 Plate Boundaries
Notes
Plates interact in three main ways.
| Boundary | Motion | Features |
|---|---|---|
| Divergent | Moving apart | Mid-ocean ridges, rift valleys (East Africa) |
| Convergent | Moving together | Trenches, volcanic arcs, mountains |
| Transform | Sliding past | Strike-slip faults (San Andreas) |
- At convergent boundaries, denser oceanic plates subduct under less dense plates.
- Oceanic-continental: trench and volcanic mountains (Andes). Continental-continental: no subduction, huge mountains (Himalayas).
- Transform boundaries make earthquakes but usually no volcanoes.
Practice
The Himalayas formed at which type of boundary?
Two continents collided, crumpling the crust upward.
The San Andreas Fault is an example of a:
The Pacific and North American plates slide past each other.
When oceanic crust meets continental crust at a convergent boundary:
Oceanic crust is denser.
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