This is a collection of notes and
worksheets that should be
complete throughout your break.
Please print for submission upon
return to school. KEEP SAFE!!!
Grade 9
Geography
workbook
Name: _______________________________
Chapter 1: Structure of the Earth
Lesson 1: Layers of the earth
Objectives
1. Accurately define the following concepts using information outlined in their text:
Lithosphere, Asthenosphere, Sial, Sima, Gutenberg discontinuity and Mohorovicic
discontinuity.
2. List the names of the four layers of the earth in the correct order.
3. Construct annotated diagrams to reflect the four named layers of the earth and their
subdivision s after viewing a chart.
Composition of the Earth
It may seem like the Earth is made up of one big solid rock, but it's
really made up of a number of parts. Some of them constantly moving!
You can think of the Earth as being made up of a number of layers, sort
of like an onion. These layers get more and more dense the closer to the
center of the earth you get. See the picture below to see the four main
layers of the earth: the crust, mantle, outer core, and inner core.
Crust
The crust (lithosphere) is the thin outer layer of the Earth where we live. Well, it looks thin on
the picture and it is thin relative to the other layers, but don't worry, we're not going to fall
through by accident anytime soon. The crust varies from around 5km thick (in the ocean floor
“sima”) to around 70km thick (on land where we live called the continental crust). The
continental crust is made up of rocks that consist primarily of silica and alumina called the
"sial". The sial is composed of lighter rocks. It forms the upper parts of the continental crust. Sial
floats on the denser materials beneath ( sima). The sima is made up of dense material. It forms
the oceanic crust and the lower part of crust beneath the continents.
Mantle
The next layer of the Earth is called the mantle. The mantle is much thicker than the crust at
almost 3000km deep. It's made up of slightly different silicate rocks with more magnesium and
iron.
1
Outer Core
The Earth's outer core is made up of iron and nickel and is very hot (4400 to 5000+ degrees C).
This is so hot that the iron and nickel metals are liquid! The outer core is very important to earth
as it creates something called a magnetic field. The magnetic field the outer core creates goes
way out in to space and makes a protective barrier around the earth that shields us from the sun's
damaging solar wind.
Inner Core
The Earth's inner core is made up of iron and nickel, just like the outer core, however, the inner
core is different. The inner core is so deep within the earth that it's under immense pressure. So
much pressure that, even though it is so hot, it is solid. The inner core is the hottest part of the
Earth, and, at over 5000 degrees C, is about as hot as the surface of the sun.
Additional sub-divisions
Asthenosphere is a zone below the lithosphere on which the plates float (upper part of the
mantle).
Lithosphere includes the crust and the uppermost mantle, which constitute the hard and rigid
outer layer of the planet.
Gutenberg discontinuity: separates the mantle from the core.
Mohorovicic discontinuity: separates the crust (lithosphere) from the mantle.
2
Activity 1.1
Complete the table below with the information you have learnt above.
Layers
Thickness
Temperature
Crust ( SIMA
&SIAL)
Mantle
Inner Core
Outer Core
3
16 marks
Composition
(What it’s madeup of?)
State ( solid,
liquid /gaseous)
Activity 1.2
Label the Outer Layers of the Earth
Label the outer layers of the Earth using the terms below.
Continental Crust - the thick parts of the Earth's crust, not located under the ocean.
Lithosphere - the crust plus the rigid, upper mantle.
Lower Mantle (semi-rigid) - the deepest parts of the mantle, just above the core.
Mohorovicic discontinuity - separates the crust and the upper mantle.
Ocean - large bodies of water sitting atop oceanic crust.
Oceanic Crust - thin parts of the Earth's crust located under the oceans.
Upper Mantle (rigid) - the uppermost part of the mantle, part of the Lithosphere.
Upper Mantle (flowing) = Asthenosphere - the lower part of the upper mantle that exhibits
plastic (flowing) properties. It is located below the lithosphere (the crust and upper mantle).
8 marks
Total 24 marks
4
Lesson 2: Layers of the Earth
Objective
1.
Explain two ways in which scientists have found out about the structure of the earth
and show an appreciation for the work they have done through discussion.
Using your text, write an email to a friend explaining how at least two ways in which scientists have
found out about the structure of the earth.
____________________________________________________________________________________
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_____________________________________________________________________________________
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Total 16 marks (2 ways 8mks, letter structure 4mks, grammar and spelling 4mks)
5
Chapter 2: CONTINENTAL DRIFT AND PLATE TECTONICS
Lesson 3: Continental Drift
Objectives:
1. Define the following correctly: Continental drift, Pangaea, Panthalassa, Laurasia,
Gondwanaland and Tethys.
2. List three evidences in support of continental drift.
In 1912, the German geologist and meteorologist Alfred Wegener (1880-1930) first proposed
the theory of continental drift, which states that parts of the Earth's crust slowly drift atop a
liquid core.
Wegener hypothesized that there was an
original, gigantic supercontinent 200 million
years ago, which he named Pangaea, meaning
"All-earth". Pangaea was a supercontinent
consisting of all of Earth's land masses and its
single ocean known as Panthalassa. Pangaea
started to break up into two smaller
supercontinents, called Laurasia and Gondwanaland, during the Jurassic period, separated by
the Tethys Sea. The continents were separating into land masses that look like our modern-day
continents.
Wegener’s evidence for continental drift was that:

the same types of fossilised animals and plants are found in South America and Africa

the shape of the east coast of South America fits the west coast of Africa, like pieces in a
jigsaw puzzle

matching rock formations and mountain chains are found in South America and Africa.
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Activity 2.1
Fill in the blanks with the most appropriate terms involved in Continental drift.
The theory of Continental Drift was coined by __________________
___________________
in __________. He believed that all the continents were united into a vast supercontinent, which
he called __________________ which meant _______________________ and a single ocean
known as ________________________ . Later, _______________________ broke into two
super continental masses____________________________ to the north, and
____________________________ to the south, separated by the ___________________ sea.
The continents continued separating into land masses that look like our modern-day continents.
(9 marks)
Activity 2.2
Using your text, give two additional evidence that supports the theory of Continental Drift.
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
( 4 marks)
Total 24 marks
7
Lesson 4: Plate Tectonics
Objectives:
1. Define the following correctly: plates, plate tectonics and convection currents.
2. Use a world map to list and identify the seven major and four minor plates.
The Earth's rocky outer crust solidified billions of years ago, soon after the Earth
formed. This crust is not a solid shell; it is broken up into huge slabs, called plates that
drift on top the soft, underlying mantle. The plates are made of rock and drift all over the
globe; they move both horizontally (sideways) and
vertically (up and down).
The theory of plate tectonics (meaning
"plate structure") was developed in the 1960's. This
theory explains the movement of the Earth's plates
and also explains the cause of earthquakes,
volcanoes, oceanic trenches, mountain range
formation, and many other geologic phenomenon.
The plates are moving at a speed that has been estimated at 1 to 10 cm per year.
Most of the Earth's seismic activity (volcanoes and earthquakes) occurs at the plate
boundaries as they interact.
The top layer of the Earth's surface is called the crust (it lies on top of the
plates). Oceanic crust (the thin crust under the oceans) is thinner and denser
than continental crust. Crust is constantly being created and destroyed; oceanic crust is
more active than continental crust.
8
Earth's Plates:
Map 1.
The current continental and oceanic plates include: the Eurasian plate, Australian-Indian plate,
Philippine plate, Pacific plate, Juan de Fuca plate, Nazca plate, Cocos plate, North American
plate, Caribbean plate, South American plate, African plate, Arabian plate, the Antarctic plate,
and the Scotia plate. These plates consist of smaller sub-plates. Activity 2.3
Plates are classified into two groups, Major and Minor, based on their size. Classify the plates
above in their correct categories; the first one is done for you.
Major plates
Minor plates
Nazca
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Lesson 5: Plate Tectonics
Objectives:
1. Identify the three types of plate boundaries.
2. Identify the forces that cause the movement of the plates based on observation from
video presentation.
There are three types of plate boundaries:
1. Convergent/ Destructive
2. Divergent / Constructive
3. Transform / Passive
At the boundaries of the plates, various deformations occur as the plates interact; they separate
from one another (seafloor spreading), collide (forming mountain ranges), slip past one another
(subduction zones, in which plates undergo destruction and remelting), and slip laterally.
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Activity 2.4
Use the arrows from the diagram above to state the movement at each plate boundary and the
resulting landform in the table below.
Convergent
Divergent
Transform
9 marks (Movement 3mks and at least two landform each 6mks)
Why do plates move?
Convection current is the force
responsible for the movement of tectonic
plates. When mantle rocks near the core are
heated, they become less dense than the
A
B
cooler, upper mantle rocks. These warmer
rocks rise while the cooler rocks sink,
creating slow, vertical currents within the
mantle (these convection currents move
mantle rocks only a few centimeters a year). This movement of warmer and cooler mantle rocks,
in turn, creates pockets of circulation within the mantle called convection cells. The circulation
of these convection cells creates friction between the overlying plates which causes the
movement of tectonic plates.
Activity 2.5 Indicate the type of plate boundary at A____________________________ and
B__________________________________
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Lesson 6: Types of Plate Boundaries ( Divergent)
Objectives:
1. Describe with the aid of diagrams the movements of Divergent plates boundaries.
2. Explain with the use of diagrams the processes and landforms associated with each
plate boundaries.
Divergent boundaries in the middle of
the oceans cause seafloor spreading. As
the oceanic plates move apart they
produce cracks in the ocean floor.
Magma rises up from the mantle and
oozes out from the cracks like a long, thin
undersea volcano. This magma cools to
form a new crust of igneous rock.
Overtime the cooling magma piles up to
form a raised ridge called a mid-ocean
ridge. The rate of seafloor spreading
depends on the mid-oceanic ridge and can vary from 1 to 20 centimetres per year.
Example : the Mid-Atlantic Ridge which extends from the Arctic Ocean to the southern tip
of Africa. The rate of sea floor spreading in the Mid-Atlantic Ridge averages about 2.5
centimetres per year. This is equivalent to 25 kilometres in a million years and as this
process has been going on for millions of
years it has resulted in the Atlantic Ocean
growing from a tiny water inlet between
Europe, Africa and America to the vast ocean
it is today.
12
Divergent plate Boundary on land
Continental and continental plate divergence
results in the formations of rifts. A rift is a
dropped zone at the point where the plates
are moving apart. As the plates move apart
the crust widens and thins, valley and
volcanoes begin to form in and around the
area. At the start of the rift formation streams
and rivers flow into the low valley and long
lakes can be created. Eventually, the
widening crust along boundary may become
so thin that a piece of continent can break off
to form a new tectonic plate. When this
happens water from an ocean can rush in to
form a new sea or ocean basin in the rift
zone.
Example : One young divergent plate boundary
that you'll recognize is actively forming the Red
Sea. Although the Arabian penninsula and
Africa were once linked to form a single
continent, they are now being ripped apart. The
white arrows show the directions the two plates
are moving. You can see that a new ocean, the
Red Sea is being formed as they separate.
13
Lesson 7: Types of Plate Boundaries ( Convergent)
Objectives:
1. Describe with the aid of diagrams the movements of Convergent plates boundaries.
2. Explain with the use of diagrams the processes and landforms associated with each
plate boundaries.
The Earth’s size has remained relatively the same since shortly after its formation 4.6
billion years ago. This implies that the Earth’s crust must be destroyed at the same rate it is being
created. The destruction or recycling of the Earth’s crust takes place at convergent
boundaries. Convergent boundaries are the zones where two tectonic plates moving towards each
other come together at their plate boundaries. At convergent boundaries tectonic plates collide
and crust is destroyed as one plate is pulled beneath the other, the type of collision depends on
the types of plates involved. These can be categorised as;



Oceanic – Continental Plate Convergence
Oceanic – Oceanic Plate Convergence
Continental – Continental Plate Convergence
Oceanic-Continental Plate Convergence (Subduction zone )
When an oceanic plate collides with a continental plate the crust forming the oceanic plate gets
bent and pulled under the continental
crust. This is because the rocks that
form the oceanic crust are denser and
thinner than the rocks that form the
continental crust. The process by which
the oceanic crust is pulled under the
continental crust is called subduction
and the zone at which this occurs at the
plate boundaries is called the
subduction zone. At the subduction
zone where the oceanic crust sinks
beneath the continental crust a deep
oceanic trench or valley is created. These can be many of thousands of kilometres long and 8 to
10 kilometres deep making them the deepest part of the ocean floor. The formation of volcanoes
is a result of the subduction of the oceanic crust. As the oceanic crust gets forced deeper into the
Earth the increasing heat and pressure releases trapped water and gases, the combing effect of
14
which is the crust melting to form magma. This magma rises and accumulates in magma
chambers which then feeds and creates volcanoes on the overriding continental plate.
Example:
Oceanic and continental
plate collisions result in
mountain and volcano
formation. Mountains are
formed as the overriding
continental plate gets lifted
up over the oceanic plate.
An example of this is found
at the boundary between the
South American continental
plate and the Nazca oceanic
plate. The South American
continental plate is being lifted over the subducted Nazca oceanic plate creating the Andes
mountain range.
NB. Earthquakes are also common at oceanic and continental plate boundaries. These occur when the
deepest part of the subducting oceanic plate break into smaller pieces. Some of the pieces become locked in
place for long periods and when they are suddenly released they generate large earthquakes.
Oceanic-Oceanic Plate Convergence
This is similar to oceanic-continental convergence in that one of the plates is subducted under the
other during the collision. At the subduction
zone a very deep trench is formed in the
ocean floor. Oceanic and oceanic plate
convergence result in the formation of
volcano chains. The crust that is pulled
under or subducted melts to form magma.
This magma rises to the top of the
overriding oceanic plates and erupts on the
ocean floor. Over millions of years, the lava
and debris from the volcanic eruptions pile
up on the ocean floor until the volcano rises
above sea level to form a volcanic island.
These types of islands are usually formed as
chains called island arcs, which run parallel
15
to the trench at the subduction zone. Oceanic-oceanic plate convergence experience similar
powerful earthquakes to oceanic-continental convergences.
Continental – Continental Plate Convergence (Collisions)
When two continental plates collide they resist downwards motion or subduction because the
continental rocks that make them up are of similar density. Instead, the crust tends to buckle and
gets pushed upwards and sideways. Thus, when two continental plates collide mountains are
formed.
Example : About 50 million years
ago the Indian plate collided
with the Eurasian plate. This
collision caused the crust to
buckle upwards and the Eurasian
plate to crumple up over the
Indian plate. Over millions of
years the continuous collisions
between the two plates has
resulted in the formation of the
Himalayan mountain range and
the Tibetan Plateau. The
Himalayas are the highest
continental mountains in the world holding many peaks at 8000 meters above sea-level, the
highest being Mount Everest at 8848 meters. Since the Indian Plate is continuing in its
northward movement into the Eurasian plate the Himalayas continue to grow at a rate of
approximately 5mm to 20mm a year.
16
Lesson 8: Types of Plate Boundaries (Transform)
Objectives:
1. Describe with the aid of diagrams the movements of Transform plates boundaries.
2. Explain with the use of diagrams the processes and landforms associated with each
plate boundaries.
A transform boundary is the zone between two tectonic plates’ slides past each other. At
transform boundaries the two tectonic plates grind past each other in a horizontal direction. This
movement result in a crack or fracture in the Earth’s crust and is called a fault.
Transform boundaries are responsible for Earthquakes. The edges of transform boundaries are
jagged and as they slide past one another they can catch and stick, locking the plates at a
particular point. When the plates become locked they cannot move and tremendous stresses build
up at the fault line. When this stress is released the plates suddenly slip into a new position. It is
this sudden movement of the plates that causes earthquakes.
Example: The San Andreas fault
zone in California is an example of
a transform boundary. It is
approximately 1,300 kilometres
long as is formed by the Pacific
plate grinding past the North
American plate. This has been
taking place over the last 10 million
years at an average rate of 5
centimetres per year.
17
Lesson 9: The Caribbean Plate
Objectives:
1. Locate and identify the extent and boundaries of the Caribbean plate using their atlas
and textbook.
2. Identify on map of the Caribbean the type of plate boundaries and resultant
landforms present around the Caribbean.
3. Locate the Cayman and Puerto Rico trenches and state their depth.
The Caribbean Plate lies in a complex area with two major plates and two minor plates bordering
it. The plate includes oceanic and continental crust. The Caribbean Sea covers most of the plate
with Central America and volcanic islands covering the rest. The edges of the plate have intense
seismic activity, frequent earthquakes and volcanic eruptions.
Between the North American Plate and this plate is a transform boundary and a
subduction zone. The Puerto Rico trench runs between the plates and is the deepest part of the
Atlantic Ocean. The trench is 8,400 meters deep. Hispaniola, Puerto Rico and the Virgin Islands
are on the Caribbean side of the trench.The area also contains seventeen active and dangerous
volcanoes. Two notorious volcanoes in the area are Soufriere Hills on Montserrat and Mount
Pelee on Martinique.
The southern border of the plate interacts with the South American Plate. The petroleum fields of
Venezuela are thought to be a result of the interaction between the two plates. Barbados,
Trinidad and Tobago islands all formed on the Caribbean side of the plates. Between these two
plates there is a transform fault, thrust faults, and a subduction zone. The western section of the
plate includes Central America. The Cocos Plate in the Pacific Ocean is subducting beneath the
Caribbean Plate forming the Central America Volcanic Arc with volcanoes in Guatemala, El
Salvador, Nicaragua, and Costa Rica.
Activity 2.6
Use your atlas to insert the boundaries of the Caribbean Plate on the map that follow, include
the Cayman and Puerto Rican trench.
18
19
20
End of topic Test
1. What is the name of the
supercontinent that consisted of
all of the present continents?
5. Which of the following is not a
divergent plate boundary?
The Great Rift Valley of East
Africa
Eurasia
Laurasia
the East Pacific Rise
Pangaea
the San Andreas fault
Gondwanaland
the Mid-Atlantic Ridge
2. Approximately how many
lithospheric plates are there?
6. Which of the following are not
associated with convergent plate
margins?
about 3
about 6
deep-focus earthquakes
about 12
rift valleys
about 24
island arcs
deep-sea trenches
3. Which plate is being subducted
beneath western South America?
7. The Caribbean plate is bounded
by _________ plate boundaries
the Pacific plate
the South American plate
convergent
the Nazca plate
divergent
the South Atlantic plate
transform
convergent, and transform
4. New oceanic lithosphere forms
at __________ .
8. The east coast of North America
represents a _________ .
divergent plate boundaries
convergent plate boundaries
convergent boundary
transform plate boundaries
divergent boundary
all of these are possible
transform boundary
none of these
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9. At convergent plate boundaries
where oceanic and continental
crust meet _________ .
12. Which of the following
mountains did not form as a
result of collision between two
continents?
no associated volcanism
occurs
Alps
oceanic crust is subducted
Tibetan plateau
continental crust is
subducted
Andes
Himalayas
oceanic crust is created
10. I once saw a bumper sticker that
said "Reunite Gondwanaland".
Which of the following would
not be part of this
reconstruction?
13. What is the topographic feature
at A called
Antacrtica
Australia
oceanic basin
India south of the Himayala
oceanic rift
North America
spreading center
11. Volcanic island arcs are
associated with __________ .
oceanic trench
14. Which of the following locations
could be represented by this
diagram??
transform plate boundaries
divergent plate boundaries
ocean-ocean convergent
plate boundaries
east coast of Africa
east coast of South America
ocean-continent convergent
plate boundaries
west coast of South America
east coast of Africa
Total 14 marks
22
Chapter: Earthquakes
Lesson 11: Introduction to Earthquakes
Objectives
1. Correctly define the following terms: Earthquake, epicentre, focus, Seismometer,
Seismographs, Richter Scale, Tsunami and Mercalli Scale.
2. Illustrate with the use of a diagram the difference between the origin/focus and the
epicentre of an earthquake.
"The ground seemed to twist under us like a top while it jerked this way and that, and up and
down and every way," wrote a person describing the experience of being in the large 1906
earthquake in San Francisco, CA.
Simply, earthquakes are the rumblings, shaking
or rolling of the earth's surface. It is usually
what happens when two blocks of the earth
suddenly slip past one another, or break apart
from each other as a result of tension caused by
prolonged energy build up.
Earthquakes happen as large blocks of the Earth’s crust move suddenly past one another because
of the force of plate tectonics. These blocks of the Earth’s crust meet at cracks called faults.
Sometimes those pieces do not slide smoothly past one another. There can be friction along
the fault – jagged edges that snag the blocks of rock. This makes it difficult for them to move
past each other. Sometimes they get stuck together temporarily. When the pieces of rock
overcome the snags, energy is released. The release of energy causes shaking at the ground
surface. These movements may create tsunami which are a huge sea wave which is most times
generated by submarine earthquakes of Richter 5.5 or greater.
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Instruments used in measuring earthquakes

Seismographs: scientific instrument used in recording the duration, magnitude, and
direction (horizontal & vertical) of earth tremor. Seismometer is a detector attached to a
seismograph which picks up even the slightest tremor. The graphic records that
seismometer produce are called seismograms.

Richter Scale: a logarithmic scale (each unit representing a 10 fold increase) ranging
from 0-10 used to compare the magnitude of earthquakes.
Parts of an Earthquake
Focus of an earthquake
The focus is also called the
hypocenter of an earthquake. The
vibrating waves travel away from
the focus of the earthquake in all
directions. The waves can be so
powerful they will reach all parts of
the Earth and cause it to vibrate like
a turning fork.
Epicenter of an earthquake is
directly above the focus on the
Earth's surface is the earthquake
epicenter. Earthquake waves start at the focus and travel outward in all directions.
Earthquake waves do not originate at the epicenter.
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Lesson 12: Effects and mitigations of Earthquakes
Objectives
1.List and describe at least 4 effects of earthquakes on buildings and or people.
2. List mitigation strategies to be taken during and after an earthquake.
Activity 3. 1
1.Try to identify the effects of earthquakes below; do you know why do they occur???
___________________________________________
_____________________________________
2.Could
___________________________________
you think of any other effects? Create a list in the box below:
Effects of earthquakes :
25
What to do during and after an earthquake.

Have a emergency kit

During earthquake if indoor drop to the ground; take cover by getting under a sturdy table
or other piece of furniture; and hold on until the shaking stops. If there isn’t a table or
desk near you, cover your face and head with your arms and crouch in an inside corner of
the building.

Use a doorway for shelter only if it is in close proximity to you and if you know it is a
strongly supported, load bearing doorway.

Stay inside until shaking stops and it is safe to go outside.

If outdoors move away from buildings, streetlights, and utility wires.

If in a moving vehicle stop as quickly as safety permits and stay in the vehicle. Avoid
stopping near or under buildings, trees, overpasses, and utility wires.

Buildings in earthquake prone areas are being designed and constructed to resist
earthquake shaking.

High occupancy buildings or critical structures should not be placed or built near faults or
on land-slide prone areas.
Activity 3. 2
You are volunteering for the Office of Disaster Preparedness and Emergency Management, the
town of Plank is located along a major fault line in a mountainous terrain. Create a brochure
explaining to the town their vulnerability and advice at least six precautionary measures for this
community.
26
Chapter: Vulcanicity
Lesson 13: Introduction to Vulcanicity
Objectives
1. Accurately define the following terms: volcano, magma, lava, sill, dyke, batholith, laccolith
2. Differentiate between intrusive and extrusive volcanic features
3. Annotate a diagram of a volcano
What is a volcano?
A volcano is a mountain that opens downward to a pool of
molten rock below the surface of the earth. When pressure builds
up, eruptions occur. Gases and rock shoot up through the
opening and spill over or fill the air with lava fragments.
Eruptions can cause lateral blasts, lava flows, hot ash flows,
mudslides, avalanches, falling ash and floods. Volcano eruptions
have been known to knock down entire forests. An erupting
volcano can trigger tsunamis, flash floods, earthquakes, mudflows and rockfalls.
How are volcanoes formed?
Volcanoes are formed when magma from within the Earth's upper mantle works its way to the
surface. At the surface, it erupts to form lava flows and ash deposits. Over time as the volcano
continues to erupt, it will get bigger and bigger.
What is the difference between lava and magma?
Magma is liquid rock inside a volcano. Lava is liquid rock (magma) that flows out of a volcano.
Fresh lava glows red hot to white hot as it flows.
Intrusive volcanic features

Laccolith are smaller mass of magma lying nearer to the earth’s surface forming a
arch/domed shaped structure.

Sill are formed when magma intrudes horizontally along bedding plane of sedimentary
rocks. E.g. The Great Whin Sill in Northern England
27

Dykes are formed by a sheet of magma which rises vertically through the surrounding
rocks and cools to form hard igneous rocks. E.g. Dike of Rhodesia,

Batholith are large dome-shaped mass of igneous rock (granite) formed when magma
intrudes the crust and cools slowly deep below the surface. E.g. Dartmoor, southwest
England.
Activity 4.1
1.
Label the intrusive and extrusive volcanic features below.
.
2. Could you define the term extrusive Volcanic features and give examples?
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
_____________________________________________________________________________________________
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Lesson 14: Parts of a Volcanoe
Objesctives :
1. Describe and label the parts of a volcano
2. Differentiate between acid and basic lava and give examples.
3. Explain how some volcanoes are explosive while others are not.
4. Examine the life cycle of a volcanoes
Parts of a volcano
Magma Chamber – A magma chamber is a
large underground pool of molten rock sitting
underneath the Earth’s crust. This magma is less
dense than the surrounding mantle and so it
seeps up to the surface through cracks and flaws
in the crust. When it reaches the surface, it
results in a volcanic eruption.
Main Vent – A volcano’s main vent is the point
in the Earth’s crust where hot magma has
reached the surface. The familiar cone-shaped
volcano builds up as ash, rock and lava ejected
during eruptions fall back to Earth around the
vent.
Crater – A volcanic crater is a circular depression in the ground caused by volcanic activity.
A volcano’s vents are located at the bottom of the crater.
Secondary Vent – On large volcanoes, magma will reach the surface through several
different vents, and not just the main vent. This can form cones, eject lava, and cause
destruction.
Secondary Cone – Secondary cones build up around secondary vents on larger volcanoes.
Scientists have categorized volcanoes into three main categories: active, dormant, and
extinct. An active volcano is one which has recently erupted and there is a possibility that it
may erupt soon. A dormant volcano is one which has not erupted in a long time but there is a
possibility it can erupt in the future. An extinct volcano is one which has erupted thousands
of years ago and there’s no possibility of eruption.
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Activity 4.2
1.Label the main parts of a volcano below : ( 7 marks)
2 Using your text, .describe the two types of lava and explain how they affect the nature of a
volcanic eruption,
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(12 marks- 2 to identify the types, 4 to describe , 6 marks to explain how they affect the eruption)
Total 19 marks
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Lesson 15: Types of Volcanoes
Objectives:
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
Describe with the use of annotated diagrams the formation of the different types of
volcanoes.
Locate areas in the Caribbean and in the world where volcanoes are found on unlabelled
map.
Describe the benefits derived by man from volcanic eruptions
Types of volcanoes
Cinder
Cones
Composite
Volcanoes
Shield
Volcanoes
Cinder cones are circular or oval cones made up of small fragments of lava from
a single vent that have been blown into the air, cooled and fallen around the
vent.
Composite volcanoes are steep-sided volcanoes composed of many layers of
volcanic rocks, usually made from high-viscosity lava, ash and rock debris. Mt.
Rainier and Mount St. Helens are examples of this type of volcano.
Shield volcanoes are volcanoes shaped like a bowl or shield in the middle with
long gentle slopes made by basaltic lava flows. Basalt lava flows from these
volcanoes are called flood basalts. The volcanoes that formed the basalt of the
Columbia Plateau were shield volcanoes.
Identify the types of volcanoes below and research an additional example of each type below:
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Activity 4.3 Insert and name the major volcanoes in the Caribbean below
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Benefits of a Volcano
There are many benefits of a volcano. Carbon Dioxide and Hydrogen are two main gases
that release into the air during the eruption. This provides food for plants and also bonds with
Oxygen to create more water. The breakdown of volcanic rocks and ash provide a great deal of
nutrition in the creation of soil. This newly fertile soil is great for the growth of new seedlings,
and the combination of carbon dioxide and water make for a wonderful growth environment.
When the lava cools, the chemical composition changes. Volcanoes are well-known sites
for a wide variety of gemstones and minerals, such as diamonds, pumice, copper, and gold. The
immense number of deposits that form due to the eruption of a volcano provides mining jobs for
many people, as well as expensive goods for interested buyers. In addition, companies that focus
on the use of geothermal energy for electric power can utilize the powerful and renewable energy
that results from a volcanic eruption. Even the sheer size and mystery of the volcano are enough
to attract tourists worldwide; not to mention the geysers and hot-springs. This is good for local
economy, family bonding, education, even creativity in writing and the arts. Tourism itself
provides a wide variety of jobs in various industries.
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