Name_____KEY NOTES for Plate Boundaries, Stresses and Faults

NOTES for Plate Boundaries, Stresses and Faults
The Lithosphere is made of the __crust__ and the UPPER rigid __mantle________. Plates
may be called by different names, like __Tectonic_______Plates, Lithosheperic Plates and
__Crustal______ Plates. ( Remember! Plates around Earth move in different directions &
cause different geologic events, which are things that happen on Earth).
Remember! What makes the plates move? >>>Answer: _Convection___ Currents in the
mantle move the plates as the core heats the slowly-flowing asthenosphere (the
elastic/plastic-like part of the mantle).
PLATE BOUNDARIES: 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____. The three types of
BOUNDARIES are divergent boundaries, _convergent_______ boundaries and transform
What is this kind
of boundary?
(define it)
Divergent Boundary
Place where 2 plates
pull away from each
(like dissecting or
What does this
kind of boundary
look like? (draw
Convergent Boundary
Place where 2 plates
crash (or crunch) or
subduct (one sink
under) each other
(like connecting or
coming together)
Transform Boundary
Place where 2 plates
slide past each other
(like cars side swiping
each other)
Question: How is the rock pulled at Divergent Boundaries? Answer: Rock gets __thin____ in
the middle as it is __pulled___ apart. This stress is called ___tension_______.
Question: What happens when the rock SNAPS from the Stress of Tension? Answer: A
Normal __fault_____ (fault is a break in Earth’s crust). Rock __drops_____ down as it
Question: What happens next @ Divergent Boundaries? Answer:__Rift valleys___ may form
on continents & ___________Seafloor______SPREADING in the ocean .
CONVERGENT BOUNDARIES – plates crash together
Question: How is the rock pushed at convergent boundaries? Answer: Rock is _pressed_ or
squeezed together.
Question: What happens when the rock is squeezed from the Stress of Compression? Answer:
A REVERSE _fault___________. Rock is forced __upward____as it is squeezed.
Question: What happens next @ Convergent Boundaries? Answer: They may form
___mountain______ ranges like the Himalayas or the Rockies.
TRANSFORM BOUNDARIES - Rocks are PUSHED AWAY in opposite directions.
Question: What happens when the rock is sheared (or “cut”) from the Stress of Shearing?
Answer: A ____strike-slip_________FAULT, which is when rocks on each side of the fault
slip past each other as they break.
Question: What happens next at Transform Boundaries? Answer: This may
cause__earthquakes_____ when the rock snaps from the pressure. (A famous fault at a
Transform Boundary is the San Andreas Fault in California.)
• HELPFUL HINTS: Shearing means cutting (“Shears” are like scissors)
• Transform boundaries run like trains going past each other in different directions & they
shake the ground!
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