Boundaries and Geologic Events
|
Boundary |
Description |
Example |
|
Divergent |
New crust is generated as the plates move away from each other |
Sea floor spreading- Atlantic Ocean Rift valley- Iceland and Africa Earthquakes and volcanoes can occur |
|
Convergent |
Crust is destroyed as a dense plate subducts (dives) under a less dense plate (e.g., basaltic ocean plates are denser than granitic continental plates) |
Ocean-Continental: volcano formation/ earthquakes Ocean-Ocean: Trench formation with volcanoes and earthquakes Continental-Continental: Mountain building, earthquakes possible |
|
Transform (Sliding) |
Plates move past each other |
Earthquakes such as those along the San Andreas Fault |
Original source of this diagram is a USGS poster. It can be found at the USGS Dynamic Earth website.
