MeanwoodValley Urban Farm1

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 LeedsTown 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 MeanwoodPark. 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

You will need: Granite, Slate,

Limestone, Millstone Grit

Magnifying Glasses

Glass

HCl

Worksheets and Answersheet

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 answersheet 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 LeedsUniversity. Inside them there are slices of rock that are so thin that the light shines through them.

Limestone:

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:

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

You will need: 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!

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?

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 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.