1. Natural Sciences and Technology Grade 5
Term 4: Planet Earth and Beyond
Sedimentary Rocks
(PPT 1)

2. Topic 3 Sedimentary Rocks
Formation of sedimentary rock
PPT 1
Gr 5 Natural Sciences and Technology – Term 4, Topic 3

3. Rocks are worn away At first, mountains are tall and rough.
Later, they are much more rounded.
Rock is worn away by weather and water.
This process is called EROSION.
Gr 5 Natural Sciences and Technology – Term 4, Topic 3

4. How sedimentary rock forms on land
Rocks are broken up by wind, rain and water.
Broken pieces washed along rivers or blown along by the wind (Process = erosion).
Broken pieces of rock, called sediments, are dropped somewhere else.
It sinks to the ground / low lying areas.
Over many years, sediments collect slowly and form layers.
Becomes compact.
Gr 5 Natural Sciences and Technology – Term 4, Topic 3

5. How sedimentary rock forms in rivers and the sea
As the water in a river moves, loose bits of rocks are carried along.
As the river slows down, pieces drop to the bottom (it is deposited).
Gr 5 Natural Sciences and Technology – Term 4, Topic 3

6. How sedimentary rock forms in rivers and the sea
Sand, stones and soil sink to the bottom of the river / sea.
Layers of sand, stones and soil form. Over time, more and more layers are deposited.
It gets very heavy and their weight presses down on the layers underneath.
Gr 5 Natural Sciences and Technology – Term 4, Topic 3

7. How sedimentary rock forms in rivers and the sea
The pressure makes the layers underneath harden and turn into sedimentary rock.
Gr 5 Natural Sciences and Technology – Term 4, Topic 3

8. What does sedimentary rock look like?
Made up of layers.
Each layer is not very heavy.
The more layers, the more weight and pressure.
Gr 5 Natural Sciences and Technology – Term 4, Topic 3

9. 3 Types of sedimentary rock
Shale
Grains of clay that have been hardened.
These break apart in large, flat pieces.
They are soft, like chalk, and can be used to write with.
Gr 5 Natural Sciences and Technology – Term 4, Topic 3

10. 3 Types of sedimentary rock
Sandstone
Soft stone.
Formed when sand grains stick together.
Sometimes in different colours.
Crumbles easily.
Gr 5 Natural Sciences and Technology – Term 4, Topic 3

11. 3 Types of sedimentary rock
3. Limestone
Rock that contains many fossils.
Mainly made up of minerals, calcium and tiny shells.
Shells are so tiny that they cannot be seen with the naked eye.
Gr 5 Natural Sciences and Technology – Term 4, Topic 3

12. Limestone quarry at Robben Island
Gr 5 Natural Sciences and Technology – Term 4, Topic 3