Download Pack 15 KS3 Chemistry rock detectives Earth structure

ROCK DETECTIVES
Earth structure
Using the words below label and then colour the different
parts of the earth’s structure
Mantle is 2,900km thick. It ranges in temperature, from 500˚C near
the crust to 4,000˚C near the core. It is made of many different
types of rock all of which are rich in minerals like silica and
ones that contain magnesium.
Crust is made of a great variety of igneous, sedimentary and
metamorphic rocks. It ranges from 5km thick to 50km thick.
At the base of the crust, next to the Mantle the
temperature can be as high as 400˚C.
Inner Core is a solid ball
which has a diameter of 2,440 km.
It is made of a mixture of iron and
nickel. Its temperature ranges from
5,000˚C to 7,000˚C.
Outer Core - is a liquid layer
made of the metals iron and
nickel. It is 2,266km thick and
ranges in temperature from 4,400˚C
and 6,100˚C.
Wren’s Nest
National Nature Reserve
ROCK DETECTIVES
Earth structure
When geologists talk about plates they mean a large, rigid slab of solid rock. The word tectonics comes from Greek and translates to
"to build." If we put these two words together, we get the term plate tectonics and this is the theory geologists use to explain how the
Earth's surface is built up. The theory of plate tectonics says that the Earth's outer layer is broken into twelve or more plates. Some are large
and some are smaller. These plates are moving all the time as they sit on top of the hot, moving material below them.
The points where the plates meet are called boundaries and there are three types:
Divergent boundaries - where the plates pull away from each other and new crust is made by hot rock filling the space between the pates.
Convergent boundaries - where one plate is pushed under another and the crust is destroyed as it melts in the hot layer below.
Transform boundaries - where the plates slide past each other and none of the crust is destroyed.
Geologists think that the hot rock beneath the plates slowly
moving a bit like a pot of thick soup when it's boiling, in a
circular motion. If you watch this happening you will see
that hot soup rises to the surface, spreads out and begins
to cool, and then sinks back to the bottom of the pot where
it is reheated and rises again. In the case of plate tectonics
its hot rock that is moving. This is repeated over and over
and makes what scientists call a convection cell. There are
other forces making the plates move, including gravity.
Gravity pulls the heavy oceanic slab into an area called the
subduction zone, this is called "slab pull" and the rest of the
plate is dragged along with it. Slab pull is now thought to be
the main driving force of plate tectonics.
Wren’s Nest
National Nature Reserve
Colour in the labelled diagram
Mid-ocean ridge
Volcano
Crust
Heat
rising
Convection cell
Mantle
Subduction
zone