Chapter 7: Plate Tectonics
Section 1
Standard: The characteristics of each layer of Earth
Standard: The movement of Earth’s lithospheric plates
Section 4 Deforming the Earth’s Crust
pp.206-213
Standard: The relationship between the movement
of the lithospheric plates and major geological
features and events
EQ: What kind of plate movement
builds mountains?
 Deformation
 Process that changes the
shape of rocks as the result
of stress
 Types of Stress
 Compression—squeeze
together
 Tension—stretched apart
 Folding—bending the rock
 Fault—when rocks break
& slide past each other
3 Types of Mountains
 Folded Mountains
 Occurs at convergent
boundaries
 Rock layers compress,
squeeze & push together
 Produce tallest mountains
 Fault Block Mountains
 Tension causes large block of
crust to drop below other
blocks of sedimentary rock
 Makes mountains with sharp,
jagged edges
 Volcanic Mountains
 Located at convergent
boundaries at subduction
zones
 Remember sea floor
spreading
 May form under the ocean
& eventually make islands
Common in the Ring of
Fire in Pacific Ocean
EQ: How do the plates move vertically?
 Uplift
 Crust pushes up, like in
mountain building
 Subsidence
 Sinking of cooler rocks,
especially on the ocean
floor
EQ: What are tectonic plates?
 Tectonic plates
 Pieces of the lithoshere that
move on top of the
asthenosphere
 Plates may be continents,
oceans or a combination,
 Thick continental plates
displace or sink more into
the asthenesphere than thin
oceanic plates do.
Summary
 Draw a diagram of each of the 3 types of mountains.
 Label it with the type of mountain
 Explain how the mountain was formed.
EQ: How do scientists know about the
deep layers of Earth?
 Seismic waves
 Vibrations from
earthquakes
 Wave speed determined by
the material they travel
through.
 Faster through solids than
liquids
 Density & thickness of the
layers are calculated by the
speed & travel time of the
wave.
The crust, mantle and core describe
the chemical composition of Earth.
 Crust
 Outermost layer
 Thinnest layer
 2 Types of Crust—
Continental is made of
oxygen, silicon,
aluminum.
2. Oceanic is made of
iron, calcium,
magnesium, as well as O2,
Si, and Al.
1.
 Mantle
 Thickest layer
 67% of Earth’s mass
 Temp. 1000 C to 3700 C
 More dense than crust
Has more magnesium
 Made of molten material -magma
 Core
 Center of Earth
 33% of earth’s mass
 Temp. 3700 C to 7000C
 Made of iron and nickel
EQ: What are the 5 physical layers of
Earth?
 Lithosphere
 Outermost, rigid layer
 2 Parts
Crust
2. Rigid, upper part
of mantle; the dividing
line between crust &
mantle
 Divided into tectonic plates
1.
 Asthenosphere
 “Plastic”, top layer of
mantle that holds the
tectonic plates
 Allows the plates move
slowly
 Made of solid rock
 Mesosphere
 Rest of the mantle
 Made of molten rock--
magma
Why is the inner core solid?
 Outer Core
 Liquid iron and nickel
 Inner Core
 Solid iron and nickel
 Most dense layer of Earth
EQ: What are tectonic plates?
 Tectonic Plates
 Pieces of the lithosphere
that move on top of the
asthemosphere
 May be continents, oceans
or a combination
 Thick continental plates
displace or sink into the
asthenosphere more than
thin oceanic plates
EQ: How do scientists know about the
deep layers of Earth?
 Seismic Waves
 Vibrations from
 Seismograph
 Records earthquake data
earthquakes
 Speed determined by the
material they travel
through
 Solids faster than liquids
 Density & thickness
determined by speed &
travel time
SUMMARY
 Write a paragraph that explains the relationship between the
3 main layers of Earth and the 5 physical layers.