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					           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                  Success Criteria:
   we should be able to:
• Know 3 types of rock (D)                  • I have stated the 3 types
                                              of rock


• Describe how rocks can                    • I have described in simple
  change over time.(C)                        terms the stages involved
                                              in the rock cycle
• Explain in detail how the
  plates of the earth can                   • I have explained plate
  move (C)                                    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
     basalt
 volcano             Rocks rise             transportation
                 to the surface by          and deposition
                 uplift and erosion.
                                                    sea

Magma            igneous rocks         sedimentary rocks
rises to            granite                mudstone
the surface
                                          high pressure
where it
                       slow              and temperature
cools rapidly.
                       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.
                                                1,300 km
                                                1,110 km
Intense heat is generated in the inner core      3,000 km
by the decay of radioactive elements like
uranium.                                            Outer core
                                                    Inner 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                                         20-60 km
     5
     0                                          Crust
         O   Si   Al   Fe   Ca   Na   K   Mg
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               Large crystals, hard rock
     igneous
     metamorphic             Sandy texture, soft rock

     extrusive               Small crystals, hard rock
     igneous
     sedimentary             Wavy layers of crystals
               Types of igneous rocks
Igneous rocks divide into two main groups:
     • Intrusive igneous
     • Extrusive igneous

• Intrusive igneous             • Extrusive igneous
  rocks, like granite,            rocks, like basalt,
  are formed when                 are formed when
  magma solidifies                magma solidifies
  within the ground.              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,        Extrusive igneous rocks,
like granite, usually have      like basalt, have crystals
clearly visible crystals.       that are usually small.



Intrusive igneous                Extrusive igneous
rocks that cool                  rocks that cool
really slowly can                really quickly can
have very big                    have a glassy
crystals.                        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                     sea
       of weather
                          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.

                                                  Sandstone is
                                                  formed from the
                                                  cementing
                                  Getting older


                                                  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
                                      forming
                                                here

                 magma         heat
             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 plate-
       like 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                  Success Criteria:
   we should be able to:
• Know 3 types of rock (D)                  • I have stated the 3 types
                                              of rock


• Describe how rocks can                    • I have described in simple
  change over time.(C)                        terms the stages involved
                                              in the rock cycle
• Explain in detail how the
  plates of the earth can                   • I have explained plate
  move (C)                                    movement and provided
                                              evidence for Pangea and
                                              continental drift

				
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