For this exam:

Write your name on all pages of your answer sheets.

All work must be turned in on separate sheets of paper.

Answer with complete sentences and proper English.

I. Slide Interpretation (20 pts.)

1. Sketch the structures. Include a scale, orientation, and legend. Explain as many

aspects of the feature as possible. For a scale, the coin is approximately 1/2 inch in

diameter, the orientation is vertical.

II. Multiple choice (20 pts.- 4 pts. each) some questions may have more than one correct answer.

2. _________ causes rocks to break, resulting in faults.

a) Normal stress

b) Differential stress

c) Lithostatic stress

d) Exam stress

e) All of the above

3. In a cross section of a fold, the region of maximum curvature is the __________.

a) overturned limb

b) crest

c) hinge zone

d) inflection point

e) hinge line

4. ________ indicate(s) the orientation of motion along a fault surface.

a) Slip

b) Chattermarks

c) Heave

d) Stratigrapchic throw

e) Striae

5. In an overturned fold ____________.

a) the crest is the same as the hinge zone

b) the younger beds always occur toward the top of the fold

c) the hinge line is vertical

d) both limbs have the same strike and dip direction

e) foliation is parallel to bedding

6. _________ influences the depth at which earthquakes occur.

a) Temperature

b) Cohesive strength

c) Extension

d) Strain rate

e) Lithostatic stress

III. Sketch / graphic interpretation (25 pts./ 5 pts each)

7. Sketch a cross section of a fold, mark and label the hinge zone, hinge line, limb, crest, and identify where you would expect to find tension gashes and axial foliation.
 
 

8. On the sketch below, indicate the direction of all principal stresses, label the sense of motion (arrows), and identify the type of faulting (normal, thrust, or strike-slip).
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

9. Identify the following types of folds (antiformal syncline, synformal anticline, etc).
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

____9a____ _____9b_____ _____9c_____ _____9d_____

10. Given two materials, fault gouge and amphibolite, identify which graph would best describe the fracure behavior of each. Why?
 
 
 
 
 
 
 
 
 
 
 
 
 
 

11. Identify the following types of faults (use proper fault nomenclature).
 
 
 
 
 
 
 
 
 
 
 
 

11. continued;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

IV. Short answer questions (25 pts./ 5 pts. each)

12. Calculate the pressure, in MPa, under 2 km of oceanic crust under a mid-ocean ridge and under the abyssal plain.

13. Explain how normal and shear stress relate to faulting. How does fluid affect this relationship?

14. Define/explain Andersonian faulting.

15. Explain the difference between frictional faulting and Coulomb fracture faulting

16. Give the average angle for normal, thrust and strike-slip faults, and explain what exceptions might account for a fault having a much different angle than expected.

V. Matching (10 pts. / 2 pts. each)

17. scratches on a fault surface a. Mylonite

18. fine-grained rock formed by plastic deformation b. Tectonic Breccia

19. rocks broken up by fault movement c. Slickensides

20. smooth polished fault surface d. Striae

21. fine-grained material of pulverized grains and clasts e. Fault gouge

f. Chattermarks

g. Augen
 
 

Bonus ( 1 pt.)

What was the orientation of the fold axis at the Odem Scout Trail. (trend & plunge)