GEOL 101 Chapter 9
Which fault will see the hanging wall move down relative to the footwall?
Normal fault
What kind of structure is present in Figure 2?
Dome
__________ faults combine elements of strike-slip and dip-slip motions.
Oblique-slip
Which type of force is responsible for normal strike-slip formation?
Shear force
What are rocks below and above a fault called?
The footwall below and the hanging wall above.
What happens when stress exceeds a brittle rock's yield strength?
The rock will experience fracture.
Imagine 2 rocks. Rock A is weaker than Rock B. Which of the following statements about rocks A and B is true?
The yield strength of rock A is lower than that of rock 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.) CHECK ALL THAT APPLY.
- folding - reverse faulting
What produces plunging folds?
A combination of folding and tilting.
What is a syncline?
A fold shaped like a right -side U.
What is an anticline?
A fold shaped like an upside-down U.
What does the term plunging fold mean?
A fold that is tilted down into Earth.
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
What kind of geologic structure is present?
Basin
Imagine 2 rocks. Under enough stress, rock A will experience plastic strain, whereas rock B will experience brittle strain. Which of the following statements about rocks A and B is true?
Both rock A and rock B will experience elastic strain before plastic or brittle strain sets in.
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.
What kind of force would create the fault in Figure 1?
Compression
Which type of force causes folding?
Compressional force
Which type of force is responsible for reverse fault formation?
Compressional force
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.
What is a fault?
Fractures along which rocks move.
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.
What kind of fault is visible in Figure 1?
Reverse fault
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.
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.
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.
Which type of fault has NO vertical motion of rocks associated with it?
Strike-slip fault
Which tectonic stress will result in a lengthening of the crust?
Tension
Which type of force is responsible for normal fault formation?
Tensional force
What is a strain?
The amount of deformation that results from an applied force.
What is stress?
The force exerted to cause deformation.
What happens when stress exceeds a plastic rock's yield strength?
The rock will experience flow.
