Notes – Theory of Plate Tectonics
What are Plates?
The Earth’s crust and upper mantle (____________) are
broken into sections called ________.
Plates move around on ______ of the mantle like rafts.
A section of the lithosphere that slowly moves over the
asthenosphere, carrying pieces of continental and oceanic
__________.
What is the Theory of Plate
Tectonics?
The theory that pieces of Earth’s lithosphere are in
constant motion, driven by _______________ currents in
the mantle.
Plates move _________ in different directions.
Cause different geologic events (like earthquake,
volcano, etc.)
What makes the plates move?
Convection Currents in the mantle move the plates as the
core heats the slowly-flowing ________________ (the
elastic/plastic-like part of the mantle).
Plate Boundaries
The ___________ of Earth’s plates meet at plate
boundaries and extended deep into the lithosphere.
Notes – Theory of Plate Tectonics
What are the three types of
boundaries?
Divergent Boundaries
FAULT – ____________ in Earth’s crust where rocks
have slipped past each other.
1. Divergent Boundaries
2. Convergent Boundaries
3. Transform Boundaries
A plate boundary where two plates move __________
from each other.
Rock gets _______ in the middle as it is __________
apart.
Fault - A ____________ Fault (fault is a break in Earth’s
crust).
Rock drops down as it breaks.
Convergent Boundaries
Type 1
Features of Divergent Boundaries – May form
Mid-ocean ridges, rift valleys, fissure volcanoes
A plate boundary where two plates move ____________
each other. There are 3 types of Convergent Boundaries.
Type 1
___________ plate colliding with a less dense
_________________ plate.
Subduction Zone: The process by which oceanic crust
__________ beneath a deep-ocean trench and back into
the mantle at a convergent plate boundary.
Type 2
______________ occur at subduction zones. For
example, Andes Mountains, South America
Type 2
_________ plate colliding with another ________ plate.
The less dense plate slides under the more dense plate
creating a subduction zone called a ____________. For
Notes – Theory of Plate Tectonics
example, Aleutian Islands, Alaska
Type 3
Type 3
A _______________ plate colliding with another
______________ plate.
Have Collision Zones: A place where folded and thrust
faulted mountains form.
May form Mountain Ranges. These are Folded
Mountains. like the Himalayas or the Rockies.
Fault - A __________ FAULT (Rock is forced upward as it
is squeezed.)
Transform Boundaries
A plate boundary where two plates move ________ each
other in opposite direction.
Rock is ___________ in two opposite directions (or
sideways, but no rock is lost)
May cause ________________when the rock snaps from
the pressure.
• A famous fault @ a Transform Boundary is the
San Andreas Fault in California.