Rocks come in many colors and sizes and are found everywhere on Earth. The document discusses the three main types of rocks - igneous, sedimentary, and metamorphic. Igneous rocks form from cooling magma and lava. Sedimentary rocks form from compression of sediments and include sandstone, limestone, and shale. Metamorphic rocks were once igneous or sedimentary rocks but were changed by heat, pressure, and chemical processes into new forms like marble and quartzite. The rock cycle shows how rocks continuously change between these three types over time.

1. Lesson 13
ROCKS

2. ROCKS
are found everywhere on Earth.
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3. ROCKS
• come in many colors.
• come in different sizes.
BOULDERS
• Rocks that are gigantic in size.
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4. Earth’s crust
is made up of different kinds of rocks. They differ in
appearance because of their different physical properties.
Physical properties depend on:
1. The kind of mineral
present in the rock;
2. The amount of
different minerals
contained in the rock;
3. How the grains of
these minerals are
arranged and held
together.
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5. TYPES OF ROCKS
• IGNEOUS
ROCKS
• SEDIMENTARY
ROCKS
• METAMORPHIC
ROCKS
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6. The Rock Cycle
The different
processes
involved in the
formation of the
three types of
rocks, namely
igneous,
sedimentary and
metamorphic.
It also shows how
rocks change
from one form to
another.
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7. IGNEOUS
ROCKS

8. Covers about
65%
of the Earth’s crust
Igneous means “fire”
Formed from the
hardening
of molten rocks.
Magma –
molten rock
Lava –
extruded rock
Intrusive igneous rocks – rocks that
are formed from magma but are not
extruded into the Earth’s surface.
Extrusive igneous rocks –
rocks that have been spewed
out into the surface of the
Earth.
GRANITE
BASALT
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9. Are the oldest
types of rocks.
Considered the
mother of all
rocks.
Also called
primary rocks.

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11. SEDIMENTARY
ROCKS

12. Covers about
8%
of the Earth’s crust
Sedimentary means “settling”
Composed of layers of sand, gravel, mud and other
sediments that have settled at the bottom of the oceans.
These materials are cemented and hardened into rocks by mean of great
pressure exerted on them below the Earth’s surface.

13. Mudstone – formed from clay and mud.
They are basically hardened mud.
Sandstone – cemented sand formed
through accumulation of sand deposits or silica
or calcium carbonate.
Conglomerate – made up of coarse-
grained material like round pebbles or gravel
which are tightly packed or cemented together.
Shales – that are fine-grained are almost
waterproof and are good underground basins for
water or oil because they are less permeable.
Mechanical means…
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14. Rock salt or halite – composed of
sodium chloride when a chloride solution is
deposited when water evaporates.
Rocks that are formed from the remains of
plants and animal that have been cemented
together. Examples:
Limestone, Chalk and Corals
Chemical means…
Organic means…
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15. METAMORPHIC
ROCKS

16. Covers about
27%
of the Earth’s crust
Metamorphic means “has been changed”
Once an igneous or sedimentary rock.
Metamorphism –
The process by which a rock is changed
into metamorphic form.

17. Metamorphism of Limestone into Marble
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18. Metamorphism of Quartzite
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19. Thank you 