Geology 2º ESO IES Monte Carrasco

1. Introduction to Geology
Hello class
Today we are going to be talking about one of my favourite subjects, which is Geology.
Can anyone of you tell me what does Geology mean? What does the word geology mean?

2. What is geology?What is geology?
The best definition for the word geology that I can find is “the science that deals with the
Earth’s physical structure and substance, its history and the processes that act on it”

3. While talking about Geology, it’s best to start from the inside of the Earth and work our way out.
There are many different layers of the Earth so we are going to watch this short little video that
talks about the different layers inside of the Earth https://www.youtube.com/watch?v=OTJc2v7q-3Y

4.  What are the two types
of crust?
 Is the mantle solid or
liquid?
 What is the core made
out of?
 What is the largest part
of the earth?
So, after watching that wonderful video that gave you a nice introduction to the different layers
of the Earth. We are going now to answer few questions regarding the information.
The first question: What are the two types of crusts?
The second question: Is the Mantle solid or Liquid?
The third question: What is the core made out of?
And, finally, the fourth question: What is the largest layer within the Earth?

5.  What are the two types of crust?
The first question, what are the two types of crust. Well, there are two types of crust and they
are called continental crust and oceanic crust. The continental crust is a granitic crust which
has a low density; whereas the oceanic crust is more basaltic and has a higher density.

6.  Is the mantle solid or liquid?
The second question: Is the mantle solid or liquid?
Well, this is actually a trick question because it kind of behaves a little bit as both. The mantle
behave is a viscous liquid it means it’s composed of a plastic flowing rock

7.  What is the core made out of?
For the third question: What is the core made out of?
This is another little bit trick question because the core consists of two different parts: the
inner core and the outer core. The inner core is a solid and it is composed of iron and nickel;
however, the outer core is more of a liquid

8.  What is the largest part of the earth?
The final question, what is the largest part of the Earth?
Out of the different layers of the earth, the mantle occupies the most space

9. Plate
Tectonics
So, now we are going to talk a
little bit about plate tectonics.
Plate tectonics occurs on the top
layer of the earth, the crust. Plate
tectonics are fragmenting pieces
of the crust; that kind of move float
around the top layer of the earth

10. Plate Tectonics
Looking at this map of plate tectonics. Can you tell me which plate do you guys live on?
Which plate is Spain on?

11. Plate Tectonics
Of course, looking at this map, we can tell that Spain is on the Eurasian plate. This plate
consists of both continental crust ad oceanic crust.

12. Pangea
As I mentioned earlier,
the plates are
constantly in motion.
They move very little
but they are constantly
moving. Each year the
plates separate or come
together about the
distance how your finger
nail grows each year.
It’s a very short distance
but over millions and
millions of years it
makes up a very large
distance

13. Types of Plate Boundaries
Since the plates are constantly in motion, and they are all completely separate from each
other, there are boundaries that exist between the plates. There are three types of
boundaries that exist: the first one is called divergent boundaries, the second one is
convergent boundaries and the third one is transform boundaries

14. Divergent
Boundaries
Let’s now talk about divergent
boundaries. Divergent
boundaries are where two
plates are spreading apart.
They are separating from each
other. At the point where these
two plates are separating, there
is often a Rift or a Ridge that it
is created. There is also a lot of
volcanic activity in these zones,
A great example is the Mid
Atlantic Ridge and Iceland. You
can see where the plates have
separated and volcanic activity
has occurred and, eventually,
created an island.

15. Convergent
Boundaries
The second type of boundaries is convergent boundaries. This occurs where two plates are
coming together. When two plates come together, there is usually a subduction zone that is
created. This is when one plate goes underneath the other one. These create tranches
usually, like the Mariana Trench in the Pacific Ocean. Also in these spots there is a lot of
volcanic activity that is involved. You can see this, for example,where the Pacific plate and
the South American plate are coming together. We have an entire mountain range called the
Andes which have been created because of this convergent boundary

16. Transform
Boundaries
And finally, the third type of boundariesis transform boundaries. These are where two plates
are sliding against to each other. One of the main deference between this boundary and the
other two is there’s not typically volcanic activity involved, but there are a lot of earthquakes.
One great example of transform boundaries is the Saint Andres Fault, in North America

17. Mid Oceanic Ridge and Rift Valleys
This geologic activity occurs where there is a divergent boundary. These formations happen
where the earth’s crust is pulling apart. The two best examples of these formations are the
Mid-Atlantic Ridge and the East African Rift. The Mid-Atlantic Ridge is where the North and
South American plates are separating from the Eurasian and African plates. The East African
Rift is an active continental rift zone in Africa. The African plate is splitting into two new plates
and will create a new oceanic basin.

18. Trenches
This geologic formation occurs where there is a convergent boundary. These occur at
subduction zones where one tectonic plate is going under another tectonic plate. This
geologic activity forms a trench. The most famous trench is the Mariana Trench in the
Pacific Ocean where the Pacific plate is going under the Mariana plate. This is the
deepest point in all of the oceans on earth

19. Transform Boundaries
Unlike divergent and convergent boundaries, no land is formed nor lost with this type of
boundary. This is where two plates slide past each other horizontally. The most famous
example on a transform boundary on land is the San Andreas Fault in the western United
States. This occurs where the Pacific plate is sliding past the North American plate

20. Volcanoes
Volcanoes are a point on the earth’s surface where magma escapes from within the earth to
the earth’s surface. These often occur on divergent and convergent plate boundaries, but
they can also occur on Hot Spots.
There are six types of volcanoes. They are: fissure volcanoes, shield volcanoes, dome
volcanoes, ash-cinder volcanoes, composite volcanoes, and caldera volcano.

21. Fissure volcanoes
Fissure volcanoes are basically a crack in the earths core where the magma escapes.
Many examples of this type of volcano can be found in Iceland.

22. Shield volcanoes
Shield Volcanoes are volcanoes that typically do not have very violent eruptions and
form with a very gentle slope. The best example of this type of volcano is the Hawaiian
Islands.

23. Dome volcanoes
Dome volcanoes are formed by slow eruptions with slow moving lava. These have steep
slopes from the cooling lava.

24. Ash-cinder volcanoes
Ash-Cinder volcanoes form from pieces of rock accumulating around the volcano. They
often only erupt once.

25. Composite volcanoes
Composite volcanoes are usually tall mountainous volcanoes with violent eruptions.
Some famous examples of this type of volcano are Mount Fuji in Japan or Mount Vesuvius in
Italy.

26. Caldera volcanoes
Finally Caldera volcanoes are formed after a previous volcano has erupted and the
surround land has collapsed into the magma chamber of the original volcano. These
volcanoes usually have a very destructive eruption as well.

27. Hot Spots-Canary Islands
These are geologic regions of weak crusts with extra hot mantle underneath. They form
magma in plumes which rise to the earth’s surface and create volcanoes. These volcanoes
do not occur on plate boundaries. Some of the most famous hotspots are Yellowstone in the
United States and the Canary Islands in Spain.

28. Earthquakes
An earthquake is the violent shaking of the earth’s surface resulting from movement on the
earth’s crust. Earthquakes often occur on tectonic plate boundaries, but it is possible that
they can be caused by humans too. Earthquakes are measured on a seismic scale from 1-no
limit. However, the strongest recorded earthquake was a 9.5 in Chile.

29. Types of Faults
Faults are fractures in the earth’s surface which cause earthquakes when there is a large
movement. There are three types of faults that cause earthquakes. These are called normal
faults, thrust faults, and strike-slip faults. In this image you can see how the different types of
faults operate.

30. Ring of Fire
The Ring of Fire is located around the Pacific Ocean where a large amount of volcanic and
earthquake activity occurs.
More than 75% of volcanoes and 90% of earthquakes happen in the Ring of Fire.
The worst earthquake ever measured was in this area as well..

31. Earthquakes and Volcanoes in Spain
Volcanoes
Earthquakes
Even though Spain is located far from the Ring of Fire, it still has some earthquakes and
volcanoes. Most of the volcanoes and earthquakes occur in the Canary Islands due to its
location above a Hot Spot. The mainland has very little seismic activity and no volcanic
activity.

32. Types of rocks
Now I am going to tell you about the different types of rocks. There are three different types
of rocks and each type has a different origin. The types of rocks are: sedimentary, igneous,
and metamorphic

33. Sedimentary Rocks
These are the most common types of rocks that you can see on the earth’s surface but
actually only make up a small portion of the crust. They are made up of particles of sand,
clay, and sea creatures that have accumulated in low lying areas on the earth’s surface and
in bodies of water. The different materials are then cemented together. Typical types of
sedimentary rocks are sandstone and limestone

34. Igneous Rocks
This type of rock is created by the cooling of magma or lava. If this occurs on the earth’s
surface, it is called extrusive. If it cools within the earth, it is called intrusive. The most
popular types of igneous rocks are granite and basalt

35. Metamorphic Rocks
Finally, the last type of rocks is called metamorphic rocks. These rocks exist from the
transformation of existing rocks through intense heat and pressure. This causes a change in
the physical and chemical makeup of the rock. Slate and Marble are both examples of
metamorphic rocks

36. Rock Cycle
Now I will briefly tell you about the rock cycle. This diagram shows how each type of
rock is changed based on a series of factors like weathering, heat, and pressure. This shows
how each type of rock is related to the other and how processes change from one type to
another over time.

37. What is erosion?What is erosion?
Erosion is defined as removal of rocks and soil by wind, water, ice and gravity.
Wind, water, ice and gravity are also known as the agents of erosion. Now let’s take a look at
erosion a little more closely

38. Difference Between Weathering,
Erosion and Deposition
BREAKS
TAKES
MAKES
Weathering breaks down earth´s surface into sediment. BREAKS
Erosion is when sediments are transported. TAKES
Deposition is when sediment is dropped by whatever is carrying them sometimes creating
new formations. MAKES

39. Water Erosion
Rain
Rivers/Lakes/Oceans
This type of erosion can be caused by rain, rivers, lakes, oceans, and even floods. Dramatic
coastlines with cliffs and grottos are caused by oceans. Deep river valleys and canyons are
caused by rivers. The Grand Canyon was formed by water erosion

40. Ice Erosion
This is caused by glaciers. The glaciers pick up rocks and drag them along the ground under
intense pressure. It acts very much like sandpaper on the earth’s surface. It creates large U
shaped valleys and even glacial lake basins like the Great Lakes

41. Wind Erosion
There are two types of wind erosion. The first example is when the wind picks up pieces of
sand, carries them away and eventually deposits them in a different location. The second is
the effect the blowing sand has on anything it comes in contact with

42. Online Activity
 Whats on Earth made this?
Now we are going to do a little activity. We are going to look at pictures of different rock
formations and determine what type of erosion took place