Download lesson 4 rock cycleplus - science

Unit 11 – Science and Humanity
Sept
Title:Task 4: Geological events that
occur on earth -The rock cycle.
•
Prior learning
– There are 3 kinds of rock – sedimentary, metamorphic and Igneous
– Igneous rocks form crystals depending on the length of time it takes
them to cool down
•
Key words
– sedimentary, metamorphic, Igneous, rock cycle, change, crust, earth,
sediments, transported, plates, tectonics, Pangea
Unit 11 – Science and Humanity
Describe long-term changes that have occurred in our universe
to our solar system and earth
By the end of this lesson
we should be able to:
Success Criteria:
• Know 3 types of rock (D)
• I have stated the 3 types
of rock
• Describe how rocks can
change over time.(C)
• I have described in simple
terms the stages involved
in the rock cycle
• Explain in detail how the
plates of the earth can
move (C)
• I have explained plate
movement and provided
evidence for Pangea and
continental drift
Unit 11 – Science and Humanity
Starter
• Get your sheets into order and then
place AO1 into plastic sleeves.
Unit 11 – Science and Humanity
Weathering breaks
down rocks.
igneous rocks
volcano
basalt
Rocks rise
to the surface by
uplift and erosion.
transportation
and deposition
sea
Magma
rises to
the surface
where it
cools rapidly.
igneous rocks
granite
sedimentary rocks
mudstone
high pressure
and temperature
slow
solidification
metamorphic rocks
slate and marble
magma melt
The core extends to about half the radius of
the Earth.
The core
It is made mostly from iron and nickel and is
where the Earth’s magnetic field comes from.
It is very dense.
5,500 C
The temperature is high and the outer core
is molten.
Towards the centre, high pressure makes
the inner core solid.
Intense heat is generated in the inner core
by the decay of radioactive elements like
uranium.
1,300 km
1,110 km
3,000 km
Inner
Outercore
core
The mantle
The mantle extends outwards from the
core to the crust: a distance of about
2,900 km.
It is mostly a semi-molten liquid upon
which the Earth’s crust floats.
The heat coming from the core
generates convection currents in the
viscous mantle that cause the crust
above to move.
2,900km
Mantle
The
crust
The crust is the thin layer of rock at
the surface upon which we live.
Eight elements make up over 98% of
the Earth’s Crust – although they are
virtually entirely in the form of
compounds.
50
% 45
40
35
30
25
20
15
10
5
0
20-60 km
O
Si
Al
Fe
Ca
Na
K
Mg
Crust
Why do plates move?
What is continental drift
theory?
It is thought that all the continents were once joined together
in a huge supercontinent called Pangaea.
Over millions of years the continents drifted apart
because the tectonic plates they were on moved apart
due to convection currents in the Earth’s mantle.

Continental drift theory
animation
PLENARY
Multiple-choice quiz
What’s the rock?
Match the rock with the correct description.
Give an example of this type of rock.
Rock type
Description
intrusive
igneous
Large crystals, hard rock
metamorphic
Sandy texture, soft rock
extrusive
igneous
Small crystals, hard rock
sedimentary
Wavy layers of crystals
Types of igneous rocks
Igneous rocks divide into two main groups:
• Intrusive igneous
• Extrusive igneous
• Intrusive igneous
rocks, like granite,
are formed when
magma solidifies
within the ground.
• Extrusive igneous
rocks, like basalt,
are formed when
magma solidifies
above the ground.
Igneous rocks and crystal size
The more slowly a rock changes from liquid to solid the
bigger the crystals grow.
Intrusive igneous rocks,
like granite, usually have
clearly visible crystals.
Intrusive igneous
rocks that cool
really slowly can
have very big
crystals.
Extrusive igneous rocks,
like basalt, have crystals
that are usually small.
Extrusive igneous
rocks that cool
really quickly can
have a glassy
appearance.
Sedimentary rocks
Sedimentary rocks are rocks formed when particles of
sediment build up and are “cemented together” by the
effect of pressure and minerals.
Fragments washed to the sea
Rocks are broken
up by the action
of weather
sea
Sedimentary
rocks
Types of sedimentary rocks
Sedimentary rocks tend to have visible grains of sediment.
Sometimes they contain fossils.
They are usually softer than igneous rocks.
Examples of sedimentary rocks are sandstone and mudstone.
Getting older
Sandstone is
formed from the
cementing
together of
grains of sand.
Metamorphic rocks
Metamorphic rocks are formed by the effect of heat and pressure on
existing rocks.
This can greatly affect the hardness, texture and layer patterns of the
rocks.
Pressure from
surface rocks
metamorphic
rock
magma
heat
forming
here
Types of metamorphic rocks
Marble, slate and schist are metamorphic.
–
Limestone is a rock often formed from the sediment of shells.
Temperature and pressure cause the rock to reform as small
crystals that are much harder. This is marble. It is used as a
hard and decorative stone in buildings, sculptures etc.
–
Slate is formed when pressure squeezes mudstone into platelike grey sheets. It is used in roofing.
–
Schist and mica are formed when mudstone is subjected to
very high temperatures and pressure. Again, they contain
layers, which is typical of many (but not all) metamorphic
rocks.
Chemical and physical
weathering
•
Surface rocks seem to be gradually reduced in size by
weathering processes.
•
Chemical weathering occurs when chemicals, such as those in
acid rain, ‘eat’ away certain rocks.
•
Physical weathering relates to rocks being broken down by the
action of wind, rain and sun. For example, during the freezing
and thawing of water in the cracks of rocks, the expansion of
water makes the rocks splinter.
•
The small broken fragments wash into rivers and, eventually,
reach the sea where they settle as sediment.
Multiple-choice quiz
Unit 11 – Science and Humanity
Safety!
Clean or report spillages
or breakages.
Wear goggles.
Wash any chemicals off your
skin straight away.
No silly or dangerous messing
about whilst equipment is out
DO NOT PLACE ANYTHING IN THE BUNSEN FLAME
Unit 11 – Science and Humanity
Today’s experiment
1. Weigh 28g of copper sulphate in a beaker.
2. Prepare a hot concentrated solution of copper
sulphate by pouring 20mL of hot water into the
beaker.
3. Stir the solution until no more can dissolve.
4. Pour the blue copper sulphate solution through filter
paper and into a conical flask (This is separate the
undissolved copper sulphate out of the solution)
5. Quickly and CAREFULLY pour equal volumes of the
solution into 2 test tubes.
6. Cool ONE of the test tubes under cold running water.
7. Tie the end of a string to a splint and the other end to
a paper clip.
8. Lower a paper clip into each test tube, stand in a test
tube rack with your name and leave till next lesson
Unit 11 – Science and Humanity
Describe long-term changes that have occurred in our universe
to our solar system and earth
By the end of this lesson
we should be able to:
Success Criteria:
• Know 3 types of rock (D)
• I have stated the 3 types
of rock
• Describe how rocks can
change over time.(C)
• I have described in simple
terms the stages involved
in the rock cycle
• Explain in detail how the
plates of the earth can
move (C)
• I have explained plate
movement and provided
evidence for Pangea and
continental drift