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ROCKS
Take the children on a walk around the Farm and show them the different
types of rock found on the Farm and explain what we use it for. The children
will have to remember the info for later
LIMESTONE – ON THE PATH LEADING TO THE SHEEP
You find limestone in the Yorkshire Dales in places such as Malham Cove.
Limestone is used in hardcore, which builders lay down before they build a
road or a building to stop the ground sinking and causing subsidence.
Limestone can be carved to make statues and sculptures such as the lions
outside Leeds Town Hall. If you look carefully at them you will notice they
have been eroded by Leeds’ acid rain
GRANITE – THE SPECKLY STONE ON THE PATH TO THE FARM YARD
Granite is a very hard rock which is formed from molten rock below the earth’s
crust. It is pushed above the surface by movement of tectonic plates
(volcanoes, earthquakes etc.) In the olden days it was used for kerb and
cobblestones, because it could resist a lot of wear and tear. Because it is so
hard, it can be worked to a high polish. Granite can be seen covering
important buildings such as banks, and is used as work tops for some
kitchens.
SLATE – ON THE FARMHOUSE ROOF
Slate is formed from mud that has been compacted over thousands of years.
As the tiny mud particles are squashed, they line up in the same directed and
become “laminated”, which means that they are in layers. These layers mean
that the rock can be broken up into thin waterproof slabs, which are ideal for
tiling roofs. Slate is expensive, though, and in recent years people use
concrete tiles on their roofs as a cheaper alternative.
MILLSTONE GRIT – REED BED WALL
Millstone Grit is a local stone formed by the deposition of sand in ancient river
deltas, and over the years it becomes squashed and hard. In the olden days,
it was used for millstones (hence its name) and you can see some of these
millstones in the beck in Meanwood Park. Because it is a local stone, many
old buildings and walls in Leeds are made from it. You can see this stone in
the wild on Ilkley Moor.
Testing Rocks
Granite, Slate,
Limestone, Millstone Grit
Magnifying Glasses
Glass
HCl
Worksheets and Answer sheet
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Children should be in four groups. Start with one rock and carry out all the
tests on the worksheet. Match the rock up with the answer sheet and see if
they can remember what the rock is used for. Continue with the rest of the
rocks, until they have worked out which rock is which and what it’s used for.
Encourage the children to look at the rocks with the magnifying glasses and
observe their structure.
The slides for the microscope were kindly donated by Leeds University. Inside
them there are slices of rock that are so thin that the light shines through
them.
LIMESTONE:
This is made from compressed fossilised sea creatures. You may be able to
see the tiny fossils of the creatures in the slide.
GRANITE:
You can see all the different minerals that crystallise to make up granite.
These crystals are formed when the molten rock cools down
MILLSTONE GRIT:
This is made from round particles. The movement of the water in the ancient
river delta where this rock was formed has worn down the particles of sand
until they are rounded and smooth. You can see these round particles in the
slide.
We haven’t got any slate as the particles are so flattened that they don’t let
any light through
Soils/ Mud workshop
Bucket of Sand
Bucket for Soil
Scoops or trowels
Soil bags
Several plastic bottles for wormeries
Plain sheets of Paper
Beakers
Stirrers
Introduction:
Explain rules of Farm
 No Running
 Fingers out of noses and mouths
 No eating till lunch
 Wash hands after project
 Shut gates
What are we going to find out about today?
Soil!
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Hand out bags one between two and go to an area of garden with bare soil.
Get the children to take a handful of soil and see if they can guess what the
ingredients are.
What can they see and feel in the soil?
They can see and feel animals, bits of plant (organic matter), stones, sand
and water.
So now we know the ingredients of soil we can make our own!
Get the children to fill their bags with plant material, stones and water (no
animals though). Get them to jump on their bags to mush the ingredients up.
Does it look like soil?
No
Why not?
The missing ingredient is time. The dead plants and animals can take months
to rot down become part of the soil, but it has take thousands of years for the
tiny bits of stone in the soil to appear. Once they may have been part of a
Cliffside, and the action that turns a Cliffside into sand is called weathering.
Here are some of the main types:
Wind:
In sandy places such as deserts the wind can pick up the sand and blast it
against rock. This acts like sandpaper and wears the rock down. The
pyramids in Egypt have been weathered in this way
Rain:
Acid rain dissolves some rocks, especially near towns and cities. If you take a
look at the lions outside Leeds town hall, you will notice that they look very
worn. This is because the acid rain in Leeds has dissolved them
Ice:
If you put a plastic bottle full of water with the lid screwed on tight, and put it in
the freezer over night, in the morning you will find a broken bottle full of ice.
This is because when water freezes it expands. So when it rains on a cold
winter’s day, and the water trickles into cracks in the rocks, in the night time
when the temperature falls below zero the water will turn to ice, expand and
make the crack bigger.
Rivers and Seas:
Flowing action by rivers and wave action by the sea bashes sand and stones
together and wears them down. You can tell rocks that have been affected in
this way as they are usually round.
Take the children to have a look at the sand and silt left in the water meadow
by the Beck then go back in the Epicentre
Put beakers on each table and fill them with a bit of soil and water. Get the
children to give the beaker a good stir and then leave in the middle of the
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table. Get them to draw the outline of a beaker on half a sheet of A4 and help
then to draw the layers of soil as they settle out
From the bottom the layers they should have are:
-Gravel
-Sand
-Silt
-Clay
At Top:
-Organic Matter
-Air bubbles
Get them to stick the corresponding substrate on their sheets with
cellotape
Wormery
Worms are very good for the soil as they mix up organic matter in it and
aerate it. We are going to make a wormery for you to take back to school that
will help you to see the way the worms move and eat.
Make wormery and go on a hunt for worms with the kids. Take a few leaves
for the worms to eat.