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lesson 11 |
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| Teachers' notes |
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| Introduction |
| This lesson
is meant as an evidence selection exercise. There
have been many theories of formation for the Earth’s
crust which attempt to explain the features we see.
Those considered here are : |
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Creationism |
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Contracting Earth
Theory |
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Isostatic uplift |
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Expanding Earth
Theory |
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Plate tectonics |
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| Running
the lesson |
| The lesson is a group-based
activity where students select from a bank of 40
statements evidence to support a theory allocated
to them. They are encouraged to choose statements
which support their theory and statements which
contradict others. |
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| Resources |
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Teachers notes
and lesson plan (this document) |
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PowerPoint presentation
– “Towards a theory of formation of the Earth’s
crust” |
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Handout / interactive
worksheet (pdf) – “Labelling Earth’s structure
diagram” |
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Evidence cards,
printed and laminated if required. There are
10 pages of evidence cards. I suggest printing
2 pages on 1 A4 sheet giving 5 sheets per
set. Print each set on a different colour
and laminate them. You will have them forever
and are less likely to lose any. |
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| You
will need to provide |
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Either sugar
paper and pens or |
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OHT sheets and
pens for the presentation. |
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| Starter |
Two
starter activities are available which involve labelling
a structure of the Earth, either using an interactive
whiteboard or manually on OHT. The writing will
stay on the presentation until it is closed so can
be revisited if required. It is therefore necessary
that students have studied Earth’s structure prior
to this lesson. All answers are given on the ‘notes’
section of the accompanying PowerPoint presentation.
The answers to the diagram labelling the Earth’s
structure (in case you are not a geologist ...)
are:
| 1. |
Continental
crust – a layer of thick, light rocks |
| 2. |
Crust
– 3 to 30 miles thick. A thin rocky crust |
| 3. |
Mantle
– Layer containing molten or semi-molten rock |
| 4. |
Core
– Central layer of the Earth |
| 5. |
Oceanic crust
– A thin layer of heavier rocks |
| 6. |
Upper
mantle – Cooler and more liquid than deep
mantle |
| 7. |
Deep
mantle – very hot liquid. Moves very slowly
(6cm/year) |
| 8. |
Outer
core – Very, Very hot liquid. Causes mantle
above to move and creates Earths magnetic
field |
| 9. |
Inner
core – solid layer of iron and nickel |
| 10. |
Lithosphere
– Crust and upper part of mantle |
| 11. |
Aesthenosphere
– hot slushy layer – moves very slowly |
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| There is
an accompanying homework sheet in PDF format which
students can either print out and complete, complete
and print out or complete and email. The choice
is yours / theirs! |
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| There is
also a slide which allows you to mind map
the students ideas about the features of the Earth’s
surface which they have seen or heard about and
any other ideas you are aware of. The writing will
stay on the presentation until it is closed so you
can revisit this slide at any time. |
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| NB Some slides on the power
point require ‘Flash Player’. Follow the link
in the CD Technical notes to install Flash
Player if necessary. It may not be possible
to use the interactive element of these slides
if you are using a Mac version. |
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| Main
Activity |
Run
through the 5 slides showing details of the 5 theories
with the students. There are suggestions in the
‘notes’ section with ideas for some demonstrations
during this part if desired. Split the class into
10 groups and assign each theory to 2 groups. You
may wish to print the relevant slides from the PowerPoint
presentation to give to the groups for a little
more guidance.
Issue a pack of evidence cards. Allow the students
10-15 minutes to read through the cards and select
the evidence which supports their theory. They will
also need to use this time to prepare some feedback
for the rest of the group. It is interesting to
see the different approach the groups with the same
theory take!
Suggested answers for Evidence cards (This may not
be an exhaustive list!)
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For: |
2, 3, 5, 6, 8, 9, 10, 11, 13,
14, 23, 28 |
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Against: |
4, 22 |
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Theory B Contracting
Earth |
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For: |
3, 7, 12, 15, 16, 18, 19, 26 |
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Against: |
6 |
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Theory C Isostatic
uplift |
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For: |
3, 21, 24, 29, 30, 31 |
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Against: |
6 |
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Theory D Expanding
Earth |
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For: |
3, 15, 25, 32, 33, 34, 35 |
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Against: |
1, 3, 6 |
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Theory E Plate
tectonics |
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For: |
3, 4, 15, 17 , 20, 21, 25,
27, 34, 37, 38, 39 |
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Against: |
6, 9, 13, 14, 36, 40 |
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| Plenary |
| You
may wish to use the final slide of the presentation
to recap plate tectonics or you may wish to allow
the students to attack each others theories and
evidence in a mini-debate. In this case, choose
one advocate of each theory and conduct a ‘question
time’ style event. |
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