
Identify plates B, D, G, I, J, L, and N
DO NOW

The diagram to the right
shows two ways to classify
Earth's layers. One way,
shown on the left, is based
on composition (what the
layers are made of). The
other way, shown on the
right, is based on physical
properties of the layers
(solid vs. liquid, rigid vs.
soft, etc.). These may also
be called zones. In most
cases, the boundaries
between the physical layers
do not line up with the
boundaries of the
compositional layers.
Layers of the Earth

The crust is the outermost,
thinnest, least dense layer.
Continental crust is made
mostly of the rock granite and
is thicker and less dense than
oceanic crust. Oceanic crust is
made mostly of the rock
basalt. Overall, crustal rocks
are rich in the elements
silicon (Si) and oxygen (O).

The oceans still have crust
under it, it just thinner than
the continental crust.
The Crust
What is the lithosphere?

Lithosphere = crust + rigid mantle
What are tectonic plates?

Earth’s lithosphere is separated into pieces that
fit tightly together like a puzzle.
Tectonic plates are the
large slabs of lithosphere
that move around on the
asthenosphere

Tectonic plates can…
Move around (they float on top of the
asthenosphere)
 Have either…

◦ Land + water
◦ Water
What allows tectonic plates to move?


Hot material
from deep inside
Earth rises and
cooler material
sinks
This motion
occurs in the
asthenosphere
Convection Current
Convection Currents
and Plate Motion
There are 7 large tectonic plates, and about 14 smaller
ones.
Learning Objective:
We will learn how plate tectonic
theory helps explain continental drift and seafloor spreading.
What is plate tectonic theory (PTT)?
Plate Tectonic Theory combines the theories of
continental drift and seafloor spreading.
 This theory states that all of Earth can be
divided into sections called tectonic plates, and
that these have the ability to move.
 Over time, these tectonic plates, with the help
of seafloor spreading, have caused Pangaea to
form today’s 7 continents.

Learning Objective:
We will learn how plate tectonic
theory helps explain continental drift and seafloor spreading.
What is a plate boundary?

The boundary or dividing line between 2
tectonic plates.
Learning Objective:
We will learn how plate tectonic
theory helps explain continental drift and seafloor spreading.
What are the types of plate
boundaries?
Transform: 2 plates SLIDE past each other
 Convergent: 2 plates move TOWARDS each
other
 Divergent: 2 plates move AWAY from each
other

Learning Objective:
We will learn how plate tectonic
theory helps explain continental drift and seafloor spreading.
Plate Boundaries
Convergent plate boundary
Transform plate
boundary
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RULES
1. Do NOT eat the materials until
instructed to do so
2. STAY in your seat at all times
3. RAISE your hand if you need something
4. WAIT for instructions before doing
ANYTHING
5. FILL out your worksheet as we go
6. Failure to follow ALL rules will result in
detention and loss of snacks
Snack Tectonics
Read Chapter 17, Section 4 and Chapter
22, Section 3
 Missing assignments are due Thursday
 Extra Credit Projects are due Thursday

FOR TUESDAY