Junior Cycle Geography CYCLONE Working with others
In pairs, discuss what you think the world would be like without rocks and minerals. Write down three ways in which things would be different.
Question Time
1. Explain why large crystals form in granite and small crystals form in basalt. 2. Igneous rocks have many uses. Can you give some examples? 3. Name one igneous rock and explain how it was formed.
Sedimentary Rocks
Sedimentary rocks make up about three-quarters of the rocks at the earth’s surface. They are made up of pieces (sediments) of other rocks and the remains of dead plants and animals. Over time, these formed layers ( strata ) that became compressed and cemented together to form rock.
Sandstone Formation
To watch a video on the formation of the Giant’s Causeway, go to YouTube and search for ‘How the Giant’s Causeway was formed (Alistair Hamill)’ (1:04).
Sandstone was formed when large amounts of sand were worn away from the earth’s crust. This sand was then carried away by wind or rivers and deposited on the beds of rivers and lakes or on the seafloor. The grains of sand built up and the deposits became compressed and cemented together.
Sandstone is typically yellow/ brown to red in colour.
How it is used Sandstone can be used to make tiles or monuments.
Location
It can be found in MacGillycuddy’s Reeks, Co. Kerry.
Sandstone is laid down in layers called strata. Can you see these layers in this image?