2. • Guys do you remember the good old days of
your childhood when you broke open all toys
and see what is there inside which makes it
work. It is a nature human tendency to be
inquisitive as to how things happen and work.
We see and hear of earthquakes, volcanoes,
lava etc. but where does it comes from?? In this
pptx we shall see what is inside the earth and
how it keeps changing form. LETS GOOOO!!!!
Remembering old days
3. What we are going to learn???!!!
• In this pptx we are going to learn
• - Layers Of Earth
• - About Rocks
• -Different Types Of Rock
• - About Rock Cycle
• Some questions about this chapter
• -At Last A Video On This Chapter
4. Layers Of Earth
• The planet earth on which we live is shaped like a huge ball which is not
absolutely spherical. As we look around where we live we see stretches of
land and water bodies and If we travel further we see huge sea and oceans.
But all this is just the upper surface of the earth. A standard cricket ball has a
diameter of 7.3 cm, a football has a diameter of 22.3cm and the earth has a
diameter of 12742kms ( at the equator). While a cricket ball is solid inside
with jute, leather etc, the football has only air. Have you wondered what is
inside our earth?? Human beings have been able to drill up to approximately
12km of the earth surface. This is just like piercing the crust. What lies inside
has been studied and analyzed by observing various activities of the dynamic
planet has been continuously changing. Even the study of meteorites which
were formed nearly the same time of earth has revealed many aspects
pertaining to the earth’s surface.
5. Definition Of Crust
• The upper most layer of the earth is called the
crust. It is the thinnest of all layers. It is around
35 km thick in the landmass ( continental areas
).and just 5 – 10 km in the oceans. The main
constituents of continental mass are Sial. ‘Si’
forms silica and ‘Al’ forms aluminum. The
oceanic crust mainly constitutes of Sima. ‘Si’
stands for silica and ‘Ma’ stands or magnesium.
6. Definition of Mantle
• This layer is about 2900km thick. It
mainly composed of Ferro-magnesium
silicates. This can be divided into two
as upper and lower mantle. This layers
are distinguished by the viscosity of
the components.
7. Definition of Core
• The core is about 3900km thick. It is the
innermost layer of the earth. it is divided in
two parts; one is the inner core and the
other is the outer core. The outer core is
made of liquid and the inner core is made
of solid. The core consists of ‘Nife’. ‘Ni’
stands for nickel and ‘Fe’ stands for
Ferrous.
8. Definition of rocks
• Any natural mass of mineral matter that makes up the
earth’s crust is called rock. The crust is called rock. The
crust of the earth is made of various types of rock with
different compositions of minerals and chemicals. They
have different color, size, density and texture and this
depends on the way they were formed. Rocks are
generally classified by composition, by the appearance
or texture and by the processes that formed them.
There are 3 types of rock : igneous, sedimentary rocks,
metamorphic rock.
9. Definition of igneous rock
• Igneous rocks are also called primary rock. These are
formed when molten magma cools and turns into solid
rocks. These rocks are further divided into two main
categories: Extrusive or volcanic rocks and Intrusive
rocks or plutonic rocks.
• Extrusive- they are formed when magma cools on the
surface of the earth
• Intrusive- they are formed when magma cools deep
inside the earth
10. Definition of Sedimentary Rocks
• Rocks keep breaking, cracking, and disintegrating by
fall, weathering action of wind and water, sun and rain
etc. these smaller pieces and particles get transported
by winds and water and collected at places in the form
o sediments. They gradually get compressed by their
own weight and harden into rocks which have visible
layers. These rocks not only have minerals but also
animal and plant fossils which lived and died in those
areas.
11. Definition of Metamorphic Rocks
•When igneous and sedimentary
rock get high heat and pressure
the get converted to
metamorphic rock.
12. Rock Cycle
• The Rock Cycle is a group of changes. Igneous rock can
change into sedimentary rock or into metamorphic rock.
Sedimentary rock can change into metamorphic rock or into
igneous rock. Metamorphic rock can change into igneous or
sedimentary rock.Igneous rock forms when magma cools and
makes crystals. Magma is a hot liquid made of melted minerals.
The minerals can form crystals when they cool. Igneous rock
can form underground, where the magma cools slowly. Or,
igneous rock can form above ground, where the magma cools
quickly.
13. • When it pours out on Earth's surface, magma is called lava. Yes,
the same liquid rock matter that you see coming out of
volcanoes.On Earth's surface, wind and water can break rock
into pieces. They can also carry rock pieces to another place.
Usually, the rock pieces, called sediments, drop from the wind or
water to make a layer. The layer can be buried under other
layers of sediments. After a long time the sediments can be
cemented together to make sedimentary rock. In this way,
igneous rock can become sedimentary rock. When the
sedimentary rock and igneous rock comes under high heat and
pressure it changes to metamorphic rock. When the
metamorphic rock comes under high heat it changes to lava .
14.
15. Questions
• Question #1
Which of the following best describes the material that makes up the earth's
asthenosphere?
• A. a rigid solid
B. a solid that is able to flow
C. a liquid at high temperature
D. a gas under great pressure
• Ans - b
16. • Question #2
The lithosphere is made up of the upper mantle and the
• A. crust
B. asthenosphere
C. hydrosphere
D. core
• Ans- A
17. • Question #3
The part of the earth that is solid but has the ability to flow is the
• A. lithosphere
B. oceanic crust
C. asthenosphere
D. inner core
• Ans- C
18. • Question #4
Which zone of the earth is made up of liquid iron?
• A. the asthenosphere
B. the outer core
C. the upper mantle
D. the inner core
• Ans- B
19. • Question #5
The boundary between the earth's crust and mantle where the speed of
seismic waves changes is called the
• A. Moho
B. shadow zone
C. magnetosphere
D. hydrosphere
• Ans- A
20. • Question #6
Geologist believe the source of the earth's magnetic field may be the
• A. core
B. magnetosphere
C. crust
D. magnetic pole
• Ans- A
21. • Question #7
The mass of an object is defined by
• A. how much the object weighs on earth
B. the amount of water the object displaces
C. the strength of the pull of gravity on the object
D. the amount of matter in the object
• Ans- D
22. • Question #8
The shock waves produced by an earthquake are called __?__
• A. seismic waves
B. sonar waves
C. laser waves
D. radiowaves
• Ans- A
23. • Question #9
The crust of the earth is made mostly of
• A. oxygen & silicon
B. iron & silicon
C. iron & nickel
D. copper & nickel
• Ans- A
24. • Question #10
The layer that makes up most of the earth's mass and volume is the
• A. mantle
B. magma
C. crust
D. core
• Ans- A