Download Rocks and Weathering ppt File

Rocks and The Rock
Cycle
8G Rock band
The rocks we see all come from the thin, solid crust
on the outside of the Earth.
They are all made of minerals.
A mineral is a chemical found in a rock.
Most minerals are mixtures of different chemicals.
Marble
Granite
Slate
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
What are the clues to help classify rocks?
metamorphic
Match Keywords and definitions
Sediments
Remains of a dead plant
or animal
Minerals
A rock that can absorb
water
Fossils
Broken bits of rock
Porous
Salts are examples of
these
8G Freeze-thaw
8G True or false?
Are these statements true or false?
1. Water expands when it freezes.
TRUE
2. Rocks contract during the day and expand
at night.
FALSE
3. Acid rain dissolves some rocks.
TRUE
4. Soft rocks weather more quickly than
harder rocks.
TRUE
Match Keywords and
definitions
Biological
Chemical
Physical
 Acid
rain pictures
8G Move it! Fast!
What are the conditions that give the biggest rate of
movement?
Amount of
water
Size of
sediments
Speed of
water flow
small
small
slow
medium
medium
medium
large
large
fast
Where would you find these conditions?
8G Move it! Fast!
What are the conditions that give the slowest rate of
movement?
Amount of
water
Size of
sediments
Speed of
water flow
small
small
slow
medium
medium
medium
large
large
fast
Where would you find these conditions?
8G Break it, move it, shape it!
Rocks may last a long time but they do change.
Even the toughest rocks can be broken down to
smaller particles. We call this process weathering.
Small particles may be moved around to new
areas. We call this transportation.
The two processes together (weathering and
transportation) are called erosion.
8G Settle down!
As the water carrying sediments slows down, the
sediments fall out of suspension.
The sediments make a layer on the bottom of a
lake or river.
New sediments are laid down on top, pressing the
ones below together.
Over thousands of years the sediments become
stuck together to make a soft rock – sedimentary
rock.
8G Age of sediments
Which rock type is oldest? How can you tell?
The fossil in layer 4 is part of an ammonite from
180 million years ago. What does this tell you about
the age of layer 3?
8G Sedimentary facts
True or false?
1. Sedimentary rocks take thousands of
years to form.
TRUE
2. Sedimentary rocks never form in layers.
FALSE
3. Sedimentary rocks often contain crystals.
FALSE
4. Salt crystals stick the grains in
sedimentary rocks together.
FALSE
8G Sedimentary facts
True or false?
1. The first process involved in making
sedimentary rocks is called weathering.
TRUE
2. Deposition lays down sediments.
TRUE
3. It is unlikely that you would find a fossil in
a sedimentary rock.
FALSE
4. Chalk is a sedimentary rock.
TRUE
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.
8H Sedimentary
Sedimentary rocks
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).
8H Igneous rocks
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)
8H Metamorphic rock
Metamorphic rocks
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.
8H Your first specimen...
?
Clues:
Crystals visible
Very tough rock
Water cannot pass through (not porous)
Is it sedimentary, igneous or metamorphic?
Igneous!
8H How about this one...
?
Clues:
Fossils present
Very porous
Layers visible
Is it sedimentary, igneous or metamorphic?
Sedimentary!
8H And this one...
?
Clues:
Grains very small
Clear layers
Not porous
No fossils
Is it sedimentary, igneous or metamorphic?
Metamorphic!
8H Last chance...
?
Clues:
Grains very small
No layers
Not porous
No fossils
Is it sedimentary, igneous or metamorphic?
Metamorphic!
8H The rock cycle
The rock cycle
8H The rock cycle
8H Rock cycle quiz
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
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
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.