1. Boundary Diagrams & Notes
Convergent Boundary
Plate Types
Movement Direction
and Effect
Landforms Created
Oceanic Vs. Continental
- Plates colliding - compressing together
- Oceanic Crust subducts and is destroyed (melted and recycled) in the
mantle
- Trench: Where plates meet, the subducting plate grabs the end of the other plate, creating a trench.
- Volcanic Arch: Magma caught between subduction zone is forced to surface of crust.
- Some mountains can be created as well
Continental Vs. Continental
- Plates Colliding- Continental Crust is compressed
- Although
crust folds, making mountains instead of descending to mantle
- Subduction occurs, No Trench
Folded Mountains are primarily created here (some volcanic activity/volcanoes can be present as well).
- Rocky Mountains, Andes, Himalayans
Oceanic Vs. Oceanic
Plates Colliding:
- Oceanic Crust subducts and is
recycled
- Trench: Very, very deep trench.
The subducting plate grabs the end of the other plate, pulling it down, creating a trench.
Marianas Trench: Pacific O. 10km deep
- Volcanic Islands: Magma caught between subduction zone is forced upward.
Divergent Boundary
Plate Types
Movement Direction and Effect
Landforms Created
Oceanic Vs. Oceanic - Under Ocean
-Plates moving apart, allowing lava to escape
- New Crust is formed, magma seeping into Ridge.
Ridge: As thin oceanic plates move apart, magma
fills the crack but is quickly cooled by the sea water.
New crust is made here.
Continental Vs. Continental - On Land
- Plates moving apart land sinks in between making a valley
- Crust expands, creating new land surface until it sinks low enough to allow ocean in an a new Island is made
-Rift Valley: As the thick continental plates separate, the land between sinks, creating valley.
- Volcanoes can result along here, but magma often cools before it reaches the surface due to thick crust.
Transform Boundary:
Plate Types
Movement Direction and Effect
Landforms Created
All types
Plates slip (rub) past/beside each other
- Source for MAJOR seismic activity - earthquakes
- No new landforms (little volcanic activity) but small hills/cliffs created at times from shifting plates.