Chapter 15.4 Deforming the Earth’s Crust

1. Chapter 15.4Deforming the Earth’s Crust

2. stress • a force that acts on rock deforming it’s shape or volume

3. YouTube video-Bill Nye Stress

4. Stress causes rocks to either fold (bend) or fault (break).

5. Folding Folded Mountains • fold-bend in rock that forms when compression shortens & thickens part of Earth’s crust –can create folded Mountains

6. Three Types of Folds • Anticline • Syncline • Monocline

7. Anticline • foldin rock layers that forms an Arch

8. Syncline • fold in rock layers that bends down to form a bowl –SMILEY FACE!

9. Anticline & syncline

10. Anticline & syncline

11. Monocline • Rock layers are folded so that both ends of the fold are horizontal.

13. Hanging Wall/Footwall

14. Normal fault hanging wall moves down relative to the footwall footwall hanging wall

15. Normal Faults

16. Reverse faulthanging wall moves up relative to the footwall footwall hanging wall

17. Reverse Fault

18. Strike-Slip Fault • Faulting at a transform boundary – fault blocks slide past each other

19. What kind of fault is this? strike-slip fault

20. Example of a strike-slip fault San Andreas fault

21. Fault-Block Mountains • mountains formed when normal faults cause large blocks of rocks to slip down due to tension Grand Teton mountain range

22. fault-block mountain

23. Uplift and Subsidence • Vertical movements in the crust are divided into two types— • Uplift – the rising of regions of the Earth’s crust to higher elevations (mountains and rebound – slow movement back to normal level after weight is removed) • Subsidence – sinking of regions of Earth’s crust to lower elevations (rift zones and oceanic crust as it moves away from the ridge)

24. plateau= large area of flat land elevated high above sea level (an area of uplift)

25. The Colorado Plateau is a 150,000 square mile region covering parts of Arizona, Utah, Colorado, and New Mexico.

26. Let's Review

27. syncline • What is a fold in rock layers that bends down to form a bowl ? YES NO

28. syncline NEXT

29. syncline NEXT

30. fold What is a bend in rock that forms when compression shortens & thickens part of Earth’s crust ? YES NO

31. A fold is a bend in rock that forms when compression shortens & thickens part of Earth’s crust. NEXT

32. A fold is a bend in rock that forms when compression shortens & thickens part of Earth’s crust. NEXT

33. fault-block mountain • What is a mountain formed when normal faults cause a block of rock to slip down? Sierra-Nevada mountain range YES NO

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36. anticline • What is a foldin rock layers that forms an arch ? YES NO

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39. In a _____________ fault, the rocks on either side of the fault slip past each other sideways. YES NO

40. In a strike-slip fault, the rocks on either side of the fault slip past each other sideways. NEXT

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42. shearing tension compression YES NO

43. The 3 types of stress are shearing, tension and compression. NEXT

44. The 3 types of stress are shearing, tension and compression. NEXT

45. tension What type of stress pulls on the crust, stretching the rock so that it becomes thinner in the middle ? YES NO

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48. B. shearing • What type of stress pushes rock in opposite directions? A. tension YES NO

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