Lesson 2 The Rhine

• Aardrijkskunde
• Middelbare school
• havo, vwo
• Leerjaar 2

Lesson 2 (1)

The Alps and weathering

For today

• Note
• Exercise
• Get to work!

What do you already know about the Alps?

Goals

• Students know how the alps are formed.
• Students know what weathering is.
• Students know different types of weathering and can explain the difference.

Some recap from last year

What are endogenous forces?

What are exogenous forces?

Can you name an example of an endogenous force?

Can you name an example of an exogenous force?

In what three ways can tectonic plates move?

Endogenous + exogenous
forces

• The earth's crust can change
  from two directions:
• Endogenous = from within the
  earth
  
• Exogenous = from outside the
  earth
  

Exogenous Forces:

•  Avalanche
  
•  Mudslide
  
•  Crumbling of rocks (weathering)
  
•  Erosion

Endogenous forces:

•  Volcanism
  
•  Earthquakes
  
•  Plate tectonics
  
•  Mountain formation
  

Forming of the Alps

Anybody knows what weathering is?

Weathering

• = The disintegration of hard rock under the influence of weather and the action of plants.
  
• Gravity causes the weathering material to roll, fall or slide down the mountain , we call this a mass movement.
  

Where is the solid rock and where is the weathering material?

Solid rock

Weathering material

Think-share-exchange

Why do we find fossils of marine animals high up in the Alps?

1. Think for yourself and write down an answer.
2. Share with one other person what your and their answer is.
3. Exchange within a group of four your answers

Get to work!

1. Read lesson 2 up to 'There are two types of weathering'.
2. Mark all the important sentences
3. Make exercises 1, 2a, 2b, 3a, 3d & 3e

Goals

• Close your notebooks and readers and join the LU

Explain how the Alps are formed.

Explain what weathering is.

What is weathering material?

Lesson 2 (2)

The Alps and weathering

Goals

• Students know how the alps are formed.
• Students know what weathering is.
• Students know different types of weathering and can explain the difference.

Recap

Explain how the Alps are formed.

Name three ways in which tectonic plates can move.

Explain what weathering is.

What is weathering material?

Weathering

• There are two kinds of weathering.

1. Mechanical weathering
2. Chemical weathering

How do the rocks weather here?

Mechanical weathering

• Mechanical means it happened with some sort of
  movement.

1. Freezing of water (ice expands) -->  frost
   weathering
2. Growing plant roots --> biological weathering
3. Shrinking of rocks during cold and expanding by
   heat from the sun.
4. --> Frost weathering

Rainwater runs into the crevices

Rainwater in crevices freezes

How do the rocks weather here?

Mechanical weathering

• Roots of trees grow in the crevices
• The roots push the rock apart
• --> biological weathering

How do the rocks weather here?

Weathering

• --> Chemical weathering
  
• Chemical weathering: changes the composition of the rock.
• Which doesnt happen with mechinal weathering!
• Moisture + oxygen react with rock.
  
• F. ex: rust

Weathering

• How do you recognize from the photo
  that this sculpture has been affected
  by chemical weathering?

How do you recognize from the photo
that this sculpture has been affected
by chemical weathering?

Weathering

• Small parts of the image are dissolved.
  You can tell by the small holes.
• Colour differences.

An example of chemical

weathering is limestone.

• An example of chemical
  weathering is limestone.

Get to work!

1. Read lesson 2 completely.
2. Mark all the important sentences
   
3. Make exercises 1, 2a, 2b, 3a, 3c, 3d, 3e, 4a, 4b* 5, 6a & 6b*
   *Only for atheneum/gymnasium

Goals

• Students know how the alps are formed.
• Students know what weathering is.
• Students know different types of weathering and can explain the difference.

Explain what weathering is.

What 2 types of weathering exist?

Explain the difference between these two types.

What types of mechanical weathering exist?

How does chemical weathering work?