plate boundaries earth’s crust plus the upper mantle forms the lithosphere. earth’s lithosphere...
TRANSCRIPT
Plate Boundaries
Earth’s crust plus the upper mantle forms the lithosphere.
Earth’s lithosphere is broken in a number of different pieces.
How these pieces move and interact is what plate tectonics is all about.
Convergent boundaries
• When 2 plates collide with one another.
Convergent boundaries
• When oceanic plates collide, one subducts under the other.
• This forms a valley in the ocean floor called a trench.
An example of a trench is the Marianas Trench.
Convergent boundaries
When continental plates collide mountains form.
Convergent boundaries
• What happens if an oceanic plate and a continental plate collide?
• Which plate would subduct?
• The oceanic plate must subduct under the continental plate.
• A continental plate is simply too buoyant to subduct under an oceanic plate.
Divergent boundariesA divergent boundary is the line between two
plates where they are moving apart.
Divergent boundaries
• Divergent boundaries can be found on continents as rift valleys.
• When a rift valley forms on land, it may eventually split the landmass.
Divergent boundaries
• Divergent boundaries can also be found in the ocean
• Sea floor spreading occurs at a mid ocean ridge.
Plate boundaries
• An edge of a lithospheric plate that slides by another plate is called a transform fault boundary.
Transform fault boundaries• When seen from
above, the feature will appear to make a zig-zag.
• Causes Earthquakes
• San Andreas Fault
Earth’s lithospheric plates• Can you identify the three types of plate
boundaries labeled A, B, and C?.