The Rock Cycle - Science This was my homework I did in Y8 It tells you all about Layers and the formation of different rocks

1. THE ROCK CYCLE
Oliver Bryant
Get it?

2. What are the different types of
rock?
 Sedimentary rocks
 Igneous
 Metamorphic

3. Sedimentary
Chalk Limestone

4. Sedimentary rocks
Small fragments of rocks fall to
the sea bed and build up in
layers, a process called
sedimentation.
The sediments get compacted
and the water squeezed out
from between them. The small
rock pieces and crystals
cement together to form
sedimentary rocks over
millions of years!
The oldest layers are at the
bottom and the youngest at the
top. There are sometimes
fossils.

5. Igneous
Granite Obsidian

6. Igneous rocks
Igneous rocks are formed by
lava and magma cooling down.
They contain randomly
arranged interlocking crystals.
The slower they cool, the
bigger the crystal. Obsidian is
an extrusive igneous rock
containing small crystals
formed when magma erupted
from volcano.
Granite are intrusive igneous
rocks formed when magma
cooled slowly underground, it
has large crystals.

7. Metamorphic
Slate Marble

8. Metamorphic
Metamorphic
rocks are formed
from other rocks
that change due to
heat or pressure
because of earth
movements. They
do not melt, but
the chemical
formula changes.
When Shale
crystals are put
under pressure
they become
arranged in layers
to form slate.
Marble is formed
from limestone.

9. Erosion
Erosion is the process of breaking things down,
large things into small. Boulders become rocks,
rocks become sand.
There are three main
types of weathering –
The process when rocks
gradually wear away.
Physical
Physical weathering is caused by changes in temperature, freezing, thawing, wind, rain
and waves. An example is when water gets into a crack in a rock and freezes, it expands
and cracks the rock more! If the ice melts, more water gets into the crack, if the rock
freezes again the crack gets even bigger until a piece of rock falls off.
Biological
Biological
weathering is
caused by
animals and
plants wearing
away the rock.
For example plant
roots grow into
cracks, making
them bigger until
eventually the
rock falls away.
Animals can
cause weathering
too by walking,
climbing and
burrowing in the
Chemical
Chemical weathering is caused
by chemicals, especially in the
rain. The rain is slightly acidic
so some minerals react
causing the rock to weather.
For example chemical
weathering can cause the
creation of caves.

10. David
David is a
marble
statue
sculptured in
Florence, in
1504.
Marble is a
metamorphic
rock, that
was formed
from
limestone. If
it was
outside,
David would
be exposed
to physical
and
chemical
weathering.

11. Ramesses II
He was
created
1000BC in
Egypt, he is
made of
granite.
Granite is
more
resistant to
weathering
because the
grains of
granite are
very close
together and
are very
strong!

12. Sediment in
rivers gets
deposited as
the river
slows down.
Bigger and
heavier
particles like
pebbles and
sand are
deposited
first. The
lighter silt
and clay only
settle if the
water is
almost still.
Deposition of sediment

13. Tectonic Plates
The Earth's surface is made up of a series of
large plates (like pieces of a giant jigsaw
puzzle).
These plates are in constant motion travelling
at a few centimetres per year.
The ocean floors are continually moving,
spreading from the centre and sinking at the
edges.
Convection currents beneath the plates move
the plates in different directions.
The source of heat driving the convection
currents is radioactive decay which is
happening deep in the Earth.
The edges of these plates, where they move
against each other, are sites of intense
geologic activity, such as earthquakes,
volcanoes, and mountain building.

14. Plate Boundaries
There are a
number of different
types of plate
boundary.
Collision zones
form when two
continental plates
collide, an example
of this is the Alps
and Himalayas.
Neither plate is
forced under the
other, and so both
are forced up and
form fold
mountains.

15. Constructive Boundaries
Constructive
boundaries form
when plates move
apart. Volcanoes
are formed as
magma rises from
the mantle when
the land splits.
They usually
under the sea, an
example being the
mid Atlantic ridge.
E.g. In Iceland

16. Destructive Boundaries
Destructive
boundaries
occur when
oceanic and
continental
move towards
each other. An
example is the
Nazca Plate in
the Andes.
Where this
happens it is
called the
Subduction
zone.

17. Subduction zone
Subduction volcanoes occur where
the earth’s plates move towards
each other and collide. The areas
where this happens are called
destructive plate margins, because
the earth’s crust is being destroyed.
One plate, usually the one that is
heavier, is forced to dive (subduct)
beneath the other into the mantle,
causing it to heat up and melt. This
melted material (magma) pushes
its way back to the earth’s surface
under great pressure, and often
erupts explosively (as lava). The
area where the two pieces of crust
are in contact is called the
subduction zone.

18. Conservative Boundaries
A conservative plate
boundary occurs
where plates slide
past each other in
opposite directions,
or in the same
direction but at
different speeds.
Friction is eventually
overcome and the
plates slip past in a
sudden movement.
The shockwaves
created produce
an earthquake.
This occurs at the
San Andreas Fault in
California.

19. Haiti Earthquake
Haiti is on the
boundaries of the
Caribbean and
North American
Conservative
pates. In 2010
magnitude 7
earthquake hit
Haiti. Buildings
were poorly built
and not
earthquake
resistant and there
were very few
resources.
1,300,000 made
homeless
300,000 Injured
220,000 Dead

20. www.BBC.co.uk/Bitesize
www.moorlandschool.co.uk/earth
www.geolsoc.org.uk
www.wkikipedia.co.uk
www.google.co.uk
Bibliography