There are 3 types of Plate Boundaries. Each one has a type of STRESS on the rock & a way that it breaks, called a FAULT :. Divergent Boundaries Convergent Boundaries Transform Boundaries. Let’s break it down…. Divergent Boundaries. Place where 2 plates pull away from each other. - PowerPoint PPT Presentation
There are 3 types of Plate Boundaries.Each one has a type of
STRESS on the rock & a way that it breaks, called a
FAULT:Divergent BoundariesConvergent BoundariesTransform
BoundariesLets break it downDivergent BoundariesPlace where 2
plates pull away from each other
How is the rock pulled at Divergent Boundaries?
Rock gets THIN in the middle as it is pulled apart.
This STRESS is called
What happens when the rock SNAPS from the Stress of Tension?
A Normal Fault (fault is a break in Earths crust)
Rock drops down as it breaks
What happens next @ Divergent Boundaries?A geologic feature or
eventMay form RIFT VALLEYS and FAULT BLOCK MOUNTAINS on
SEA-FLOOR SPREADING in the ocean
Helpful HintsDivergent is like dissecting or dividing
If you pull warm bubble gum or silly putty, it will thin in the
middle until it is stressed so much that it breaks.
Happens on land & under H2O
Convergent BoundariesPlaces where plates crash (or crunch)
together or subduct (one sinks under)
How is the rock pushed at convergent boundaries?Rock is pressed
or squeezed together.
This stress is called COMPRESSION
What happens when the rock is squeezed from the Stress of
Compression?A REVERSE FAULTRock is forced upward as it is
What happens next @ Convergent Boundaries?May form Mountain
Ranges.These are Folded Mtns. Like the Himalayas or the
FoldingFolding occurs when rocks are compressed or deformed and
they buckle under the stress.
The diagram below illustrates how rocks fold.
The crest of the fold, where the rock layers slope downward form
The valley of the fold where the layers slope toward the lower
axis form the syncline.
May form Volcanoes @ Subduction Zones as denser oceanic plate
dives under less dense continental plate.
What else happens @ Convergent Boundaries?Helpful
HintsConvergent = Connecting boundaries Rock crunches up to make
folded mountains.Rock goes down under @ subduction zone.
Transform BoundariesPlace where 2 plates slide past each
How is the rock broken at Transform Boundaries?Rock is pushed in
two opposite directions (or sideways, but no rock is lost)
This stress is called SHEARING
What happens when the rock is sheared (or cut) from the Stress
of Shearing?A STRIKE-SLIP FAULTRocks on each side of the fault slip
past each other as they break.
What happens next at Transform Boundaries?May cause Earthquakes
when the rock snaps from the pressure.A famous fault @ a Transform
Boundary is the San Andreas Fault in California.
Helpful HintsShearing means cutting (Shears are like
scissors)Transform boundaries run like trains going past each other
in different directions & they shake the ground!
San Andreas Fault, CA Faulting
Can you match the boundary name correctly with its diagram?