© oup: to be used solely in purchaser’s school or college 8h the rock cycle rock types changing...
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© OUP: To be used solely in purchaser’s school or college
8H The Rock Cycle
Rock types
Changing rocks
The rock cycle
8H The Rock Cycle
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Rock types
8H The Rock Cycle
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8H Name that rock...
Believe it or not, rocks can be classified into groups – just like living organisms.
The three main groups are:
igneous sedimentary metamorphic
What are the clues to help classify rocks?
?
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8H Sedimentary
Often look like flat plates stuck together.
Grains often visible, these can crumble apart.
Fossils can be present.
Rocks come from flat beds.
Often porous (let water pass through easily).
Sedimentary rocks
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8H Rock factory
A volcano is a giant rock factory.
Magma (molten rock) from below the ground is pushed to the surface and cools.
The rock that forms is called igneous rock.
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8H Igneous rocks
Tough rocks with no plates visible.
The crystals (if you can see them) often interlock and run in different directions.
No fossils present – EVER!
Rocks do not form in flat beds.
Non-porous (will not let water through)
Igneous rocks
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8H Metamorphic rock
Often ‘sugary’ with particles that can be arranged in sheets or randomly.
Remains of fossils sometimes present – but not often.
Beds often have wavy bands.
Often less porous than sedimentary rocks – but metamorphic rocks show a wide range of porosity.
Metamorphic rocks
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8H Your first specimen...
Crystals visible
Very tough rock
Water cannot pass through (not porous)
Is it sedimentary, igneous or metamorphic?
Igneous!
Clues:
?
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8H How about this one...
Fossils present
Very porous
Layers visible
Sedimentary!
Clues:
?
Is it sedimentary, igneous or metamorphic?
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8H And this one...
Grains very small
Clear layers
Not porous
No fossils
Metamorphic!
Clues:
?
Is it sedimentary, igneous or metamorphic?
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8H Last chance...
Grains very small
No layers
Not porous
No fossils
Metamorphic!
Clues:
?
Is it sedimentary, igneous or metamorphic?
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1. Igneous rocks form from cooling magma produced by volcanoes.
2. Sedimentary rocks never contain fossils.
3. Igneous rocks are usually very porous.
4. Sedimentary rocks often have layers.
5. Granite is a metamorphic rock.
8H True or false?
True or false?
TRUE
FALSE
FALSE
TRUE
FALSE
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Changing rocks
8H The rock cycle
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8H All change!
The two processes together (weathering and transportation) are called erosion.
Reminder:
Rocks may last a long time but they do change.
Even tough igneous rocks may be broken down to smaller particles. We call this process weathering.
Small particles may be moved to new areas. We call this transportation.
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8H Squeezing rocks
What happens to particles from eroded rock?
Sediments may be laid down by water. Over many years the sediments build up and stick together to form a new sort of rock.
Sometimes earthquakes and volcanoes bury old rocks underground. Very high temperatures and pressures change these rocks into new ones called metamorphic rocks.
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The rock cycle
8H The rock cycle
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8H The rock cycle
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1. Metamorphic rocks are made by…
a) heat and pressure acting on other rocks
b) particles dropping out of suspension in streams and rivers
c) a small factory outside Manchester.
2. Which of these would you NOT find in sedimentary rocks…
a) fossils
b) layered structure
c) interlocking crystals of minerals.
8H Rock cycle quiz
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3. The rock cycle is…
a) a way to explain how types of rocks are converted to other forms
b) an explanation of how heating and cooling can break down rocks
c) a musical by Andrew Lloyd Webber.
4. You could find the density of a rock sample by…
a) dividing its mass by its volume
b) dividing its volume by its mass
c) multiplying its volume by its mass.
8H Rock cycle quiz
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5. Slow cooling of magma produces rocks with…
a) large crystals
b) small crystals
c) no crystals.
6. You can dissolve the carbonate in a limestone sample using
a) hydrochloric acid
b) cold water
c) boiling water.
8H Rock cycle quiz