Mountain Building

Total Flash Cards » 42
 
1. 

Deformation:

 

Refers to all changes of a rock body.

 
2. 

Where does most deformation take place?

 

Plate boundaries.

 
3. 

Stress:

 

The force that produces deformation, i.e. compression, tension, etc

 
4. 

Strain:

 

The RESULT of stress: folds, faults, etc.

 
5. 

Types of stress:

 

Compression, tension, & shear.

 
6. 

Compression:

 

--><-- Rocks pushed into each other. Found at CONVERGENT boundaries.

 
7. 

Tension:

 

<-- --> Rocks pulled apart. Found at DIVERGENT boundaries.

 
8. 

Shear:

 

Either one or both rocks slide past each other. No direct contact, found at TRANSFORM boundaries.

 
9. 

What type of fault is the San Andreas?

 

Transform, Right-lateral.

 
10. 

What happens when a fault is parallel to stress?

 

No mountains appear. (no significant uplift)

 
11. 

What happens when a fault "bends" along stress, i.e. is not parallel?

 

Mountains and valleys can appear. (significant uplift)

 
12. 

Elastic deformation:

 

Once stress is removed, rock returns to original position. Like playing with an elastic rubber band.

 
13. 

What can happen when a rock's elastic limit is reached, i.e. its been stretched too much?

 

One of two things: Flow - rock stretches permanently. Fracture - Rock breaks.

 
14. 

Flow is ___ deformation.

 

Ductile (flowing)

 
15. 

Fracture is ____ deformation.

 

Brittle (breakage)

 
16. 

4 Factors that influence deformation:

 

Temperature, time, pressure, rock type.

 
17. 

How can warm/cold temp affect deformation?

 

Warm: Ductile, causes deep rocksCold: Brittle, surface rocks

 
18. 

How does time affect deformation?

 

Quick: BrittleSlow: Ductile

 
19. 

How does rock type affect deformation?

 

Shale & Marble: DuctileGranite & Gneiss: Brittle

 
20. 

Fold is an example of what?

 

Ductile deformation.

 
21. 

Faults are an example of what?

 

Brittle deformation. (breakage has occured)

 
22. 

Arch and trough like features are caused by:

 

Folds (compressional features)

 
23. 

Anticline:

 

Arches.

 
24. 

Syncline:

 

Troughs. U

 
25. 

Fracture are a result of...

 

Brittle deformation (breakage)

 
26. 

Two major types of faults:

 

Dip-slip & Strike-slip.

 
27. 

Dip-slip faults are a result of what two types of stress?

 

Tensional and Compressional (pushing and pulling)

 
28. 

2 Parts of a dip-slip fault :

 

Hanging wall and footwall.

 
29. 

Dip-slip movement is parallel to what?

 

the inclination of fault surface.

 
30. 

2 Dip-slip faults:

 

NormalReverse & Thrust

 
31. 

Normal faults = what kind of stress?

 

Tensional <-- ---> Normal = pulling

 
32. 

Result of normal fault activity:

 

Lengthening of crust.

 
33. 

Hanging wall moves down in what fault type?

 

Normal.

 
34. 

Reverse thrust result of what type of stress?

 

Compressional. --> <--Reverse = pushing.

 
35. 

Hanging wall moves UP in what fault type?

 

REVERSE.

 
36. 

Reverse faults have inclination greater than....

 

45 degrees.

 
37. 

Thrust faults are ____ 45 degress.

 

Less than.

 
38. 

Not dip-slip, but....

 

Strike-slip.

 
39. 

Strike slip involves what type of stress?

 

Shear.

 
40. 

Three ways stress can be shear...

 

Left-lateral, right-lateral, and transform.

 
41. 

When facing a fault, right-lateral means...

 

Crustal block on opposite side of fault is moving right, and vice versa for left-lateral.

 
42. 

Transform fault

 

Motion between two plates. San Andreas is an example.