GEOLOGY 12 KEY CHAPTER 12 TAKE-HOME QUIZ INTERNAL STRUCTURES AND PROCESSES Score Part B = / 55 PART B CHAPTER 12 Isostacy and Structural Geology 1. Using the terms below, label the following diagrams and place arrows on the drawings that show relative movement of the hanging wall and footwall. normal fault reverse fault thrust fault Normal Fault Thrust Fault Reverse Fault 2. Brittle rocks tend to _RUPTURE_ in response to stress. 3. Fractures in rock along which there is no movement or displacement are called JOINTS. 4. Fractures in rock along which movement has occurred are known as FAULTS. 5. When geologist talk about the STRIKE of a rock layer, they refer to a compass direction measured parallel to the earth's surface. 6. When geologist talk about the DIP of a rock layer, they mean the tilt or angle of the layer, measured down from the horizontal plane. 7. If a geologist said that a dike was oriented N35 E, s/he would be telling you the STRIKE of the dike. 8. Which type of faulting commonly occurs as a result of tensional (pulling apart) stresses. a. reverse fault b. normal fault c. thrust fault d. strike-slip fault 9. Faults which show vertical motion are described as a. dip-slip faults b. oblique faults c. thrust faults d. strike-slip faults 10. From the view of an observer facing a strike-slip fault, the displacement across the fault is such that features appear to have shifted to the left. What specific type of fault is this? a. reverse fault b. normal fault c. right-lateral fault d. left-lateral fault
- 2-11. If the hanging wall has moved up relative to the footwall, the fault is REVERSE. 12. If the hanging wall has moved down relative to the footwall, the fault is NORMAL. 13. A reverse fault with a very low angle plane is called a THRUST fault. Use Figures 1-4 below to answer questions #14 to 25. 14. Referring to Fig. 1 feature "A" is called the STRIKE 15. Referring to Fig. 1 feature "B" is called the DIP 16. Referring to Fig. 2, which side of the fault is the hanging wall? A 17. Referring to Fig. 2, which side of the fault is the footwall? B 18. Referring to Fig. 2, which side of the fault moved UP relative to the other? A 19. Referring to Fig. 2, what specific type of dip-slip fault is shown? _REVERSE FAULT_ 20. Referring to Fig. 3, which side of the fault is the hanging wall? B 21. Referring to Fig. 3, which side of the fault is the footwall? A 22. Referring to Fig. 3, which side of the fault moved down relative to the other? B 23. Referring to Fig. 3, what specific type of dip-slip fault is shown? NORMAL FAULT 24. Referring to Fig. 4, what type of fault is pictured? STRIKE-LIP FAULT 25. Referring to Fig. 4, is this a left or right lateral fault? LEFT-LATERAL FAULT
- 3-26. Which of the following could be produced by compressional forces? a. reverse faults b. thrust faults c. overturned folds d. all of the above 27. Which one of the following faults would most likely be formed by tensional forces a. thrust b. normal c. reverse d. strike-slip 28. A transform fault is also a a. joint set b. strike-slip fault c. dip-slip fault d. oblique-slip fault 29. In a reverse fault the a. older rock may be pushed over younger rock b. hanging wall move down relative to the footwall c. blocks slip horizontally d. forces involved are in tension rather than compression 30. A fault along which there is only horizontal movement is called a a. thrust b. normal c. reverse d. strike-slip 31. A fault along which there is movement in both the horizontal and vertical directions is called a. transform fault b. strike fault c. reverse fault d. oblique-slip fault 32. Crustal thickening can be caused by all of the following except a. thrust faulting b. recumbent folding c. reverse faulting d. normal faulting 33. A continent is in isostatic equilibrium. A large mountain range on the continent erodes away. In response, the base of the continental crust will a. rise b. sink c. not move d. melt 34. A folded structure which dips away from the centre in all directions is called a. a dome b. a basin c. a syncline d. an anticline
- 4-35. By definition, in an anticline a. the limbs dip towards each other and the oldest rock are at the centre b. the limbs dip towards each other and the youngest rocks are at the centre c. the limbs dip away from each other and oldest rocks are at the centre d. the limbs dip away from each other and the youngest rocks are at the centre 36. In a syncline, the a. oldest rocks are in the core of the fold b. oldest rocks overlie younger units c. youngest rocks are in the core of the fold d. limbs dip away from each other 37. The mountain belt that forms the western part of North America is called the: a. Appalachian Mountains. b. Himalayas. c. North American Cordillera. d. Ouachita Mountains. 38. The craton: a. is the portion of a continent with the highest mountains. b. is the geologically stable portion of continents. c. is the youngest portion of continents. 39. Precambrian shields: a. are very ancient rocks representing the central cores of continents. b. have been destroyed by subduction over time. c. were once divergent plate margins. d. were in existence at the time Earth formed. 40. Folds and reverse faults in a mountain range suggest: a. compressional stresses. b. tensional stresses. c. deep-water deposition of sediments. d. all of these. 41. Which is not a type of terrane? a. exotic. b. suspect. c. accreted. d. accumulated. 42. Which of the following is a source of terranes? a. micro-continents. b. fragments of distant continents. c. ocean crustal fragments. d. all of these 43. A mountain belt formed through ocean-continent convergence may contain: a. fold and thrust belts. b. thick accumulations of marine sedimentary rocks. c. high-grade metamorphic rocks. d. all of these.
- 5-44. The Himalayas, Appalachians, Alps and Ural Mountains formed as a result of: a. continent-continent convergence. b. ocean-continent convergence. c. ocean-ocean convergence. 45. The Andes Mountains of South America and the Cascade Range of North America formed as a result of: a. ocean-ocean convergence. b. continent-continent convergence. c. ocean-continent convergence. 46. It would appear that most mountain ranges form as a result of: a. some form of convergent tectonics. b. some form of divergent tectonics. c. some form of transform tectonics. Refer to the diagram below to answer questions #47 to 50. 47. What is the name of the type of fault labeled L? NORMAL FAULT 48. What type of forces (compressional, tensional or sheer) would have produced a fault of this type? TENSIONAL 49. What is the name of fold type K? SYNCLINE 50. At which type of PLATE BOUNDARY would fold type K most likely have been produced? CONVERGENT
- 6-51. In the space provided below, sketch and clearly label a cross section that contains an anticline cut by a reverse fault. (3 marks)