Download EJD-Rock Cycle

The Rock Cycle
Learning Objectives
To understand how different rock types are formed.
Learning Outcomes
To be able to describe the formation, providing examples or each of
the three types of rock.
ALL: Describe the
formation of each
rock type (D/C).
Most: Provide
named examples
of each type of
rock (B)
Some: Explain how
each rock type can
be transformed
during the rock
cycle (A/A*)
START UP TASK
• Using Pg. 120-121 in your text, scan the
information and take notes on the three types
of rocks that are referenced in this section:
– Igneous
– Sedimentary
– Metamorphic
Rocks
We have been using
rocks for thousands of
years for many
different purposes
Rocks can have
different properties
from each other and
this gives them
different uses
Uses of Rocks
How many different uses for rocks can you
think of?
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Fossil Fuels
Building material for houses, roads, bridges and cities
Making cement and concrete
The salt in our food is a mineral and pumice stones are
used in toothpaste
Decoration – from stone statues to gemstones in jewelry
Most metals are found in the form of ores
Making glass
Sandpaper
Types of Rock
There are three main
types of rock
These types share
similar properties and
are formed in the same
way
The Rock Cycle
Rocks get broken down by weathering to form
sediments to make sedimentary rocks
Rocks are melted to form magma and cool to make
igneous rocks
Rocks are transformed under extreme heat and
pressure to make Metamorphic rocks
And all these processes are going on constantly
at the same time!
The Rock Cycle
All of these processes take
place at the same time
Rocks are slowly over time
being turned into different
types of rocks over and
over again
This is called the rock cycle
The Rock Cycle
ALL: Describe the
formation of each
rock type (D/C).
Most: Provide
named examples
of each type of
rock (B)
Some: Explain how
each rock type can
be transformed
during the rock
cycle (A/A*)
The Rock Cycle
Beginning of turn
Process
End of Turn
Sediment
Compaction and cementation
Sedimentary rock
Sedimentary rock
Weathering and erosion
Sediment
Sediment
ALL: Describe the
formation of each
rock type (D/C).
Most: Provide
named examples
of each type of
rock (B)
Some: Explain how
each rock type can
be transformed
during the rock
cycle (A/A*)
The Rock Cycle
ALL: Describe the
formation of each
rock type (D/C).
Most: Provide
named examples
of each type of
rock (B)
Some: Explain how
each rock type can
be transformed
during the rock
cycle (A/A*)
Sedimentary Rocks – Properties
Sedimentary rocks tend
to be crumbly and
porous
They are made of layers
stuck together by
mineral crystals
They can contain fossils
within their layers
Sedimentary rocks are
the only ones that are
porous (allow water to
pass through them)
Sedimentary Rocks – How are they
made?
Sedimentary rocks are made from sediment
grains which come from eroded rocks
Sediment grains are transported by water, wind or
ice
They form layers called ‘strata’
Pressure and mineral reactions harden the
sediment in to sedimentary rock
Igneous Rocks – Properties
Igneous Rocks tend to
be very hard
They contain crystals
and the size of the
crystals depends on
how slowly the rock
cooled when it was
formed
The quicker the rock
cools when it forms
the smaller the
crystals will be
Igneous Rocks– How are they made?
Igneous rocks are formed from magma (molten
rock) cooling and becoming solid
They can be made below the surface as
‘intrusive rocks’ or above the surface as
‘extrusive rocks’
The magma that makes igneous rocks comes
from other rocks that have been melted
Metamorphic Rocks – Properties
Metamorphic rocks are
usually hard
They may contain tiny
crystals or layers or
distorted fossils
They are the hardest to
identify
Metamorphic comes
from the word
‘metamorphism’ which
means ‘to change’
Metamorphic Rocks– How are they
made?
Metamorphic rocks were once either igneous or
sedimentary rocks
Igneous and sedimentary rocks that are
beneath the earths surface can be subject to
intense heat and pressure
This heat and pressure can change them in to
metamorphic rocks
The Rock Cycle
1. Igneous rocks are formed from solidified
________ or lava. If the rate of cooling is
slower, the crystals are ________.
2. Metamorphic rocks are formed when rocks
are at a high temperature and high
________.
3. Sedimentary rocks form from the hard
parts of marine animals or ______
fragments of broken rock.
bigger
chalk
crystalline
eroded
limestone
magma
marble
pressure
sedimentary
The Rock Cycle
1. Igneous rocks are formed from
solidified magma or lava. If the rate
of cooling is slower, the crystals are
bigger.
2. Metamorphic rocks are formed when
rocks are at a high temperature and
high pressure.
3. Sedimentary rocks form from the
hard parts of marine animals or
eroded fragments of broken rock.
The Rock Cycle
1. Describe how an igneous rock may become
a sedimentary rock, which in turn may
become a metamorphic rock. Explain what
must happen for the metamorphic rock to
become an igneous rock.
2. Name one example for each of the
following rock types:
a) Igneous rock
b) Metamorphic rock
c) Sedimentary rock
ALL: Describe the
formation of each
rock type (D/C).
Most: Provide
named examples
of each type of
rock (B)
Some: Explain how
each rock type can
be transformed
during the rock
cycle (A/A*)
Which rock am I?
Sedimentary Rock
• I am formed from layers of sediment laid down in lakes or
seas over millions of years.
•
I tend to be crumbly and porous.
•
My layers are stuck together with salt crystals (minerals)
•
Fossils (remains of plants and animals) can form in my
sediments
•
Examples of me are limestone, chalk and sandstone
Which rock am I?
Igneous Rock
• I am formed from cooled molten magma which is pushed up
to the surface of the crust – and often out through volcanoes.
•
I am called extrusive if I cool above ground and intrusive if I
cool below the ground.
•
I am very hard and have crystals. The slower I cool the larger
my crystals.
• Examples of me are granite and basalt.
Which rock am I?
Metamorphic Rock
• I am formed from existing rocks that have been changed by
great heat and pressure over long periods of time.
•
I am usually hard.
•
I may have really tiny crystals, I may have some layers and I
may have some distorted fossils.
• Examples of me are marble, slate and schist.