Download Sedimentary, igneous or metamorphic rocks?

Sedimentary, igneous or metamorphic rocks?
Student tasks
1. Match the three rock types to their two correct definitions.
These are formed when existing sedimentary or igneous
rocks change because of heat and/or pressure, e.g.
marble.
Sedimentary rocks
This is a rock formed by molten magma or lava, which
has cooled. If it forms underground, it is called
intrusive, e.g. granite. If it forms on the surface from
a volcano, it is extrusive, e.g. basalt.
These rocks consist of crystals, which are larger when
the magma has cooled slowly. They are hard and
difficult to erode. They are impermeable so do not let
water pass through them.
Igneous rocks
These rocks are usually very resistant to weathering
and erosion. They have crystals similar to igneous
rocks. They are impermeable and one type, slate is an
excellent roofing material.
The layers in this rock type are lines of weakness,
known as bedding planes. They are permeable so
water can pass through them. They are easily eroded
and often contain fossils, e.g. limestone.
Metamorphic rocks
A rock formed when sediment is deposited in layers on
the bottom of a shallow sea or lake. The weight of
more layers above compresses the sediment into rock,
e.g. sandstone.
Tips from the Chief Examiner:



Weaker students mix up the types of rock – you must revise thoroughly!
Students often confuse formation with features – do you understand the
difference?
An example ALWAYS helps no matter what the question!
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Sedimentary, igneous or metamorphic rocks?
2. Label the six statements below as sedimentary, igneous or metamorphic:
Sed/Ig/Meta
These are formed when existing sedimentary or igneous rocks change
because of heat and/or pressure.
This is a rock formed by molten magma or lava, which has cooled. If it
forms underground, it is called intrusive but if it forms on the surface
from a volcano, it is extrusive.
These rocks consist of crystals, which are larger when the magma has
cooled slowly. They are hard and difficult to erode. They are
impermeable so do not let water pass through them.
These rocks are usually very resistant to weathering and erosion. They
have crystals similar to igneous rocks. They are impermeable and one
type is an excellent roofing material.
The layers in this rock type are lines of weakness, known as bedding
planes. They are permeable so water can pass through them. They are
easily eroded and often contain fossils.
A rock formed when sediment is deposited in layers on the bottom of a
shallow sea or lake. The weight of more layers above compresses the
sediment into rock.
3. Match the examples to the three rock types and statements above.
basalt
marble
chalk
limestone
granite
slate
4. Match the examination questions to the correct statement above:
a.
b.
c.
d.
e.
f.
g.
h.
i.
Explain how sedimentary rocks are formed (3 marks)
Describe the features of sedimentary rocks (3 marks)
Give an example of a sedimentary rock (1 mark)
Explain how igneous rocks are formed (3 marks)
Describe the features of igneous rocks (3 marks)
Give an example of an igneous rock (1 mark)
Explain how metamorphic rocks are formed (3 marks)
Describe the features of metamorphic rocks (3 marks)
Give an example of a metamorphic rock (1 mark)
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Sedimentary, igneous or metamorphic rocks?
5. Identify the three rock below as sedimentary, igneous or metamorphic:
Chain of Craters Road, Hawaii. Image used courtesy of the US Geological
Survey. education.usgs.gov/lessons/schoolyard/superposition.html
© Copyright Anne Burgess and licensed for reuse under a Creative
Commons Licence. /www.geograph.org.uk/photo/1370873
Image used courtesy of Rod Lightbody and licensed for reuse under a
Creative Commons Licence. www.geograph.org.uk/photo/2160541
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Sedimentary, igneous or metamorphic rocks?
Teaching notes
1. The first sheet is a simple heads and tails activity. It could also be completed as a colour
coding exercise. Students then need to identify whether the information refers to
characteristics or formation.
2. In their books, students could then be asked to write their own three-mark examination
question with a simple point marked, mark scheme.
3. The second sheet provides more reinforcement on the differences between the three
types of rocks. The exercise is extended by linking each box to an examination question.
This is useful as students can be shown that mark allocation often depends on the number
of points made. The importance of always providing a named example is also made
clear.
4. The final activity provides three images of a sedimentary, an igneous and a metamorphic
rock in situ. These are also available in an accompanying PowerPoint presentation.

Igneous – The lava flow image of the Chain of Craters road in Hawaii can be also
used to show the relatively slow speed of flow of the basalt and superposition.

Sedimentary – The sedimentary rocks at Scarfskerry, near John O’Groats form a
well-defined sea stack.

Metamorphic – The metamorphic rock demonstrates a complex pattern of folds
indicating its deformation over millions of years.
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