1. Weathering, Erosion and Distinctive Landscapes
Explain the terms weathering and erosion.
Name and describe the process of chemical and mechanical weathering
Describe and draw a limestone pavement
Describe surface and underground landforms of a karst landscape
Understand how this topic appears on the exam papers.

2. Mind Map: Weathering
Lets do a mind map to remember what you learn from junior cert geography

3. Key words Denudation Mechanical weathering Chemical weathering
Biological weathering

4. Denudation
This is all processes involved in the shaping of the earths crust
Denudation = weathering and erosion

5. Weathering
Weathering is the breaking down and decay of rocks that are exposed to the weather
There are three types
Mechanical – Frost and temperature changes
Chemical – Rocks are dissolved
Biological – Plants and animals

6. Erosion Erosion is the breaking down and removal of the rock.
Three types of erosion
Moving water (rivers and sea)
Moving ice (Glaciation)
Moving air (wind)

7. Mechanical Weathering
3 Types
Freeze Thaw Action
Exfoliation
Crystallisation of salts – When salts in a rock grow they can split the rock apart.

8. Mechanical Weathering Freeze Thaw Action
Weathering by frost is called freeze thaw action

9. In order for freeze thaw action to occur you need to have…
Temperatures that rise above and fall below freezing (0°C)
A good supply of water from rain, snow, sleet or hail.

10. Freeze Thaw Action
Where do you think this action usually occurs???

11. Mechanical Weathering - Exfoliation
‘Onion Peeling’
Major contrasts in temperature
Rises very high during the day and drop very low at night
The change in temperature expands and contracts the rock causing the outer skin to shatter.

12. Class Activity
Summarise the three types of mechanical weathering into your copies.

13. Biological Weathering
Action of plants, animals and man can speed up mechanical and chemical weathering

14. Chemical Weathering Keywords
Carbonation
Oxidation
Hydration
Hydrolysis

15. Chemical Weathering Four types of chemical weathering Carbonation
Oxidation
Hydration
Hydrolysis
Research the types of chemical weathering..
Teach the class.

16. Distinctive Landscape
Granite Landscape
Limestone Pavement – Karst Landscape. Burren Co. Clare

17. Karst Keywords Burren Tower Karst Landscape Carbonation
Calcium Carbonate
Calcite
Limestone Pavement
Swallow Hole
Cavern
Dripstone Formations

18. Karst Region These are bare limestone regions
Ireland’s best known Karst region the Burren in Co. Clare
Burren = Rocky place (An Boireann)
Soil in the area removed by Erosion
International Example – Tower Karst Landscapes

19. The Burren

20. Surface and Underground Landforms
Limestone Pavements
Swallow holes
Underground
Caverns
Dripstone formations

21. The Burren

22. Limestone Pavement Examples Near Black Head in the Burren Co. Clare
Marble Arch Uplands in Co. Fermanagh

23. Revision… Limestone In your groups do a limestone revision mindmap…
Remember the characteristics of limestone!!

24. Limestone Pavement Formation
Limestone pavements from from the process of carbonation ‘All the Cs!’
Carbon dioxide in the air + rain = Weak Carbonic Acid.
Lands on limestone rock creating a chemical reaction.
Hydrogen in the carbonic acid separates the calcium carbonate (limestone) into calcium and bicarbonate atoms
These are soluble and are washed away… as a result the limestone is dissolved.

25. Limestone Pavement An exposed area of limestone
Limestone is permeable. When rainwater falls onto the surface of the limestone it moves underground through joints and cracks in the rock.
It has grikes and clints

26. A Limestone Pavement is just like a bar of dairymilk chocolate!!
Each group will be given a bar of chocolate…. I’d like you to describe the physical features of the bar of chocolate…
DO NOT EAT IT!! WE NEED IT FOR THE REST OF THE CLASS!!

27. Clints These are the top flat pieces of the limestone.
These are formed by chemical weathering dissolving away some of the rock landscape.

28. Clints

29. Grikes These are the joints or cracks between the Clints
These have been formed by chemical weathering.
Carbonic acid (acid rain) expands the width and depth of the cracks

30. Grikes

31. Class Activity Read page 59 of your book. Exam Question
Describe the formation of any one rock type
and how it produces a distinctive landscape.
Describe the formation of limestone… notes from rock chaper
Describe formation of a karst landscape and limestone pavements
Use two examples Burren Co. Clare and Tower Karst Landscape (page 63)

32. Sinkholes/Swallow holes
An opening in the bed of the river through
which a river disappears underground in a
limestone region

33. Swallow Hole
Bedding Plane
Grikes

34. Class Activity: Sinkholes
Read the formation of a sinkhole on page 60 of your book.
Summarise the landforms in grouop

35. CAVE

36. Cavern

37. Animation of a Cavern

38. Activity: Read page 61
Write out caverns into your own words into your copies

39. Dripstone formations
Include stalactites, stalagmites, pillars, columns and curtains.
Formed from the mineral calcite. Calcium carbonate in its purest form.
Read page 62 in your book. Summarise into your own words.

40. Stalagmites
When the drops of water fall to the floor and evaporate, they also deposit calcite. These deposits build up in a conical shape to form Stalagmites

41. Stalagmites

42. Stalactites
When water containing dissolved calcium carbonate seeps through the rock, some drops hang from the roof of the cave/cavern for a while. Some of the water evaporates leaving behind deposits of calcite. These deposits build up over thousands of years and hang from the roof to form Stalactites.

43. Stalactites

44. Pillar
In time, the Stalactites and Stalagmites grow and join up to form pillars.

45. Pillar

46. Exam Questions: Could be asked for Underground or Surface Landforms
Prepare questions to suit both surface and underground.

47. Weathering, Erosion and Distinctive Landscapes
Explain the terms weathering and erosion.
Name and describe the process of chemical and mechanical weathering
Describe and draw a limestone pavement
Describe surface and underground landforms of a karst landscape
Understand how this topic appears on the exam papers.