1. Constructive and Destructive Processes
Ms. Meskie
Ms. Krutty

2. Check This Out!
Volcanoes

3. Stations Station 1 Station 2 Station 3
Page 1, question 1: What do you think will happen when water is poured over the “hill”?
Station 2
Page 2, question 9: What will happen when you rub sandpaper over the limestone?
Station 3
Page 2, question 12: What is the effect of water on limestone?
Page 2, question 13: What is the effect of the acid on limestone?

4. Constructive Processes Destructive Processes
Build the earth up
Destroy or break down part of the earth

5. Constructive or Destructive?

6. Volcanoes Constructive process Builds up land around the volcano
1943 in farmer’s field in Mexico – built a mountain in 9 years
1964 off coast of Iceland – now a large island

7. Constructive or Destructive?

8. Plate Tectonics and Mountain-Building
Constructive Process
Oceanic plate more dense than continental plate
Oceanic plate pushed under continental plate, continental plate crumples
Two plates collide and both are pushed up and crumpled
Video 1
Video 2

9. Plate Tectonics and Mountain-Building
Subduction – the process that takes place at convergent boundaries in which one tectonic plate sinks under another into the Earth’s mantle because it is more dense than the other
Density – mass per unit volume
(Density=Mass/Volume)
Orogeny (uplift) – a process in which the forces produced by convergent tectonic plates produce mountains

10. Constructive or Destructive?

11. Weathering and Erosion
Destructive Process
Weathering 1st to weaken the rock, erosion 2nd to break it away
2 kinds of weathering:
Mechanical – breaks down rocks
Wind
Water
Plants
Animals
Chemical – changes rocks into something new
Chemicals (Ex. Acid rain)

12. Weathering and Erosion
Weathering – the breaking down of rocks, soil, and minerals through contact with the atmosphere
In-Situ – with no movement; takes place in that spot
Erosion – movement of rocks and minerals by agents such as ice, water, wind, and gravity
Hydration – a process in which a rock takes in water, and the increased volume creates stress in the rock, breaking it up

13. Weathering and Erosion
Carbonation – a process in which carbon dioxide mixes with rain, making the rain acidic, which in turn breaks down certain types of rocks
Oxidation (rusting) – a process in which water and oxygen mix and weaken the rock (this occurs mostly with metal ores)

14. Weathering and Erosion
Plant’s roots have grown into the rock
Causes some of the rock to break apart
Mechanical or chemical weathering?

15. Weathering and Erosion
Iron in rock reacts with oxygen in air
Creates rust and weakens the rock
Mechanical or chemical weathering?

16. Weathering and Erosion
Carries away weathered rock
Wind blows dust off side of cliff
Silt carried downstream by river
Rocks fall off side of cliff due to gravity
Wind
Water
Ice

17. What happens to the weathered rock that is carried away?

18. Deposition Constructive
Sand and pieces of rock are deposited by water, wind, or ice as a result of erosion
Constructive or destructive?
Constructive

19. Summary Constructive Destructive Volcanoes
Plate Tectonics and Mountain-building
Subduction
Density
Orogeny
Deposition
Weathering and Erosion
Weathering
In-Situ
Erosion
Hydration
Carbonation
Oxidation

20. Station 1 Observations Which substance moved first? Next? Last?
Did the size of the particles affect the rate of erosion?
Would the amount of water affect the rate of erosion?
Would the hardness of the rain affect the rate of erosion?
If you wanted to control erosion on a hill, what type of particles would be best to use?
What do you think happens to the surfaces of mountains that experience large amounts of rainfall?

21. Station 2
Observations
How is rubbing sandpaper across a rock like windblown sand hitting a rock?

22. Station 3 Observations What is the effect of water on limestone?
What is the effect of the acid on limestone?
How long do you think it will take for the acid to completely dissolve the limestone?
How might this process occur in nature?
Is this an example of mechanical or chemical weathering?

23. Post-Lab Quiz
What is the difference between a constructive process and a destructive process?
Carbon dioxide in the air can combine with rain to create acid rain. When this acid rain hits limestone, it weakens the limestone through a process called carbonation. Would this be considered mechanical or chemical weathering?

24. 3. Which process caused this change in landscape?
Post-Lab Quiz
3. Which process caused this change in landscape?

25. 4. Which process caused this change in landscape?
Post-Lab Quiz
4. Which process caused this change in landscape?

26. 5. Which process caused this change in landscape?
Post-Lab Quiz
5. Which process caused this change in landscape?

27. 6. Which process caused this change in landscape?
Post-Lab Quiz
6. Which process caused this change in landscape?