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Ch. 10 Mastering 1. A. Which type of force causes folding? Compressional Force B. What is an anticline? a fold shaped like an upside-down U C. What is a syncline? a fold shaped like a right-side-up U D. Imagine an anticline has been eroded to a flat surface. How would the rock age change as you walked across that flat surface? Rocks would be youngest on the edges and oldest in the middle. E. Imagine a syncline has been eroded to a flat surface. How would the rock age change as you walked across that flat surface? Rocks would be oldest on the edges and youngest in the middle. F. What produces plunging folds? a combination of folding and tilting G. What does the term plunging fold mean? a fold that is tilted down into Earth H. Imagine a fold has been eroded to a flat surface. In general, how would you know whether this fold is plunging? Nonplunging folds look like straight lines at the surface, and plunging folds look like wavy lines 2.

3. A. Based on what you learned in the video, which of the following statements regarding joints is true? Joints are fractures in rocks where very little to no movement has occurred. B.

Faults,

discontinuous.

C.

D.

4. A. What is a scarp? the trace of a fracture called a normal fault, where a portion of crust slides down the fault surface B. Alluvial fans are composed of material built up from sediment from the foot of the mountains to the valley floor. They are evidence that __________. Death Valley is a tectonically active region. C. The Basin and Range consists of north-south trending mountain ranges separated by basins. What causes this distinct topography? Extension due to normal faulting causes valley floors to sink D. The split cinder cone along the Southern Death Valley Fault is evidence that __________. the Pacific and North American plates are moving alongside each other along strike-slip faults. 5. A. What is a fault? fractures along which rocks move B. What are rocks below and above a fault called? the footwall below and the hanging wall above C. Which type of force is responsible for normal fault formation? tensional force D. Which type of force is responsible for reverse fault formation? compressional force E. Which type of force is responsible for normal strike-slip formation? shear force F. Which type of fault has NO vertical motion of rocks associated with it? strike-slip fault 6. What is rock deformation, and how might a rock body change during deformation? Deformation is a rock’s reaction to stress, which can cause a rock to change its shape or position. 7. What is elastic deformation? The temporary and reversible deformation of a rock caused by the gradual application of stress. During elastic deformation, the chemical bonds within the rock do not break. 8. Which statement(s) correctly describe(s) brittle deformation and ductile deformation? SELECT ALL THAT APPLY.

Both types of deformation are permanent. Brittle deformation describes a rock breaking as a result of stress, whereas ductile deformation describes a rock bending or folding as a result of stress. 9. How do monoclines form? Movement along a steep fault in basement rock pushes up a portion of the ductile rock layers above it. 10. A. Which of the following statements best describes the orientation of rock layers for a structural dome or structural basin? Rock layers wrap around a single point. Domes and basins are round and will fold in all directions around a central point. B. If strike and dips symbols were placed on a map of a basin, which way would the dips point? Dips point down toward the center. C. Based on the ages of the rock layers in the cross-section, what kind of fold is in Figure 1? (Note: In map view, this feature would have a bull’s-eye pattern.) basin. Basins have the youngest rocks in the center and the oldest on the outside. D.

Dome

11. How do geologists infer the orientation of rock structures that are mainly below Earth’s surface? After measuring the strike and dip of several outcrops within an area, geologists graphically present these data in the form of geologic maps. 12. A. Which of the following scenarios best describes the deformation that will occur in different parts of the crust? Brittle deformation is dominant in the shallow crust; ductile deformation is dominant in the deep crust. Temperatures are lower near to the surface, making the rock “cold” and more likely to shatter. B. Which of the following is an example of how rocks will respond to compressional stress? (Note: there may be more than one correct answer.) Reverse faults occur when the landscape is shortened. Folding occurs when the landscape is shortened. C. Which tectonic stress will result in a lengthening of the crust? Tensional stress pulls things apart. D. Which of the following images best describes how a rock in the deep crust would be deformed as a result of shear stress?

13. A. A monocline is a type of a(n) ____ Fold B. Choose the correct definition of a monocline: A large steplike fold in otherwise flat-lying sedimentary rocks C. Which of the following is required for a monocline to form? Reactivation of steeplydipping faults in basement rocks D. A cross-section of a monocline is shown below. Use what you learned in the video to label the parts of the monocline and the directional forces that created it.

E.

The sedimentary layers were worn away by stream erosion...