Intro

1. Objective 10/14/2011 Describe the three major types of folds and faults by modeling them. Intro Does rock bend or break or both?

2. Deforming the Earth’s Crust

3. Folds • Folding – the bending of rock layers due to stress

4. Folds: Take the layered clay in both hands, and slowly bend upwards (do not break the clay!) until a fold appears. Draw what you see:

5. Folds: Take the layered clay in both hands, and slowly bend upwards (do not break the clay!) until a fold appears. Draw what you see:

6. Folds: • Anticline – upward arching folds

7. Folds: Take the layered clay in both hands, and slowly bend downwards (do not break the clay!) until a fold appears. Draw what you see:

8. Folds: Take the layered clay in both hands, and slowly bend downwards (do not break the clay!) until a fold appears. Draw what you see:

9. Folds: • Synclines – down-ward folds

10. Folds: Take the layered clay in both hands. While keeping both hands horizontal, move one hand upwards slowly, until a new fold appears. Be careful not to break the clay! Draw what you see:

11. Folds: Take the layered clay in both hands. While keeping both hands horizontal, move one hand upwards slowly, until a new fold appears. Be careful not to break the clay! Draw what you see:

12. Folds: • Monocline – rock layers are folded so that both ends of the fold are horizontal

13. Faults • Fault – a break in a body of rock along which one block slides relative to another

14. Faults With each piece of clay in your hands, model a normal fault by moving your right hand downwards and your left hand upwards. Draw what you see:

15. Faults With each piece of clay in your hands, model a normal fault by moving your right hand downwards and your left hand upwards. Draw what you see:

16. Faults • Normal Fault – causes the hanging wall to move down relative to the footwall

17. Faults With each piece of clay in your hands, model a reverse fault by moving your right hand upwards and your left hand downwards. Draw what you see:

18. Faults With each piece of clay in your hands, model a reverse fault by moving your right hand upwards and your left hand downwards. Draw what you see:

19. Faults • Reverse Fault – causes hanging wall to move up relative to the footwall

20. Faults Normal Fault Reverse Fault • When rocks are pulled apart • One slab of rock slides DOWNWARD • When rocks are pushed together • One slab of rock slides UPWARD

21. Faults With each piece of clay set on the table in front of you, model a strike-slip fault by pushing one piece of clay forward while pulling the other piece towards you. Draw what you see.

22. Faults With each piece of clay set on the table in front of you, model a strike-slip fault by pushing one piece of clay forward while pulling the other piece towards you. Draw what you see.

23. Faults • Strike-slip Fault – opposing forces cause rock to break and move horizontally (like at a transform boundary)

24. Folds and Faults • Folding = bending • Fault = breaking

25. Summary • When stress is put on rocks, they can either bend (fold) or break (fault). Syncline, Anticline and Monocline are three types of folds. Normal, Reverse and Strike-Slip are three types of faults. Each play a role in creating the different types of landforms around us.

26. Objective 10/14/2011 Describe the three major types of folds and faults by modeling them. Outro The diagram shows a profile of rock layers. Which point indicates the oldest exposed layer? A B C D