Geology 1100 Homework 5

Block X is the block on the left with the labeled layers. Which of the following choices is correct? A. Block X is the hanging wall. B. It is not possible to tell whether Block X is the hanging wall or footwall. C. Block X is the footwall.

A. Block X is the hanging wall

Which of the following terms refers to the process of mountain building? A. orogeny B. cratonic platform C. brittle and ductile deformation D. tectonic foliation

A. orogeny

Motion on which of the following faults results in a fault scarp? Choose one or more: A.dip-slip fault B.reverse fault C.strike-slip fault D.thrust faultE.normal fault

A.dip-slip fault B.reverse fault D.thrust fault E.normal fault

What is associated with strike-slip faults ? Associated with shear stress Motion is primarily horizontal Results in crustal lengthening or shortening Crust is shortened or lengthened

Associated with shear stress Motion is primarily horizontal

What does this figure illustrate? A. how fault scarps are formed B. strike-slip faulting C. hanging wall moving up D. vertical displacement

B. Strike-slip faulting

In this illusration ? A. the displacement of Layer B shows that this is a strike-slip fault. B. the displacement of Layer B shows that this is a thrust fault. C. Block X is the hanging wall. D. Block X is the footwall.

C. Block X is the hanging wall

Determine the type of stress that caused the faulting. A. E-W compression B. E-W tension C. N-S compression D. N-S tension

C. N-S compression

Brittle deformation Choose one: A. is more likely to occur deep in the crust than at the surface. B. is favored by high-temperature, high-pressure conditions. C. occurs when many atomic bonds are broken quickly and rock pieces separate. D. produces folds, like anticlines.

C. Occurs when many atomic bonds are broken quickly and rock pieces separate

The image shows more than 8 feet of offset on the Richardson Highway in Alaska that resulted from a magnitude 7.9 earthquake along the Denali Fault in 2002. Notice the Trans Alaska Pipeline in the background. This type of offset suggests that what type of fault motion occurred in this area? A. normal faulting B. thrust faulting C. right-lateral strike-slip faulting D. left-lateral strike-slip faulting

C. Right-lateral strike-slip faulting

Which statements are true about strike-slip faults ? A.Magmas are generated during faulting. B.Their motion is dip-slip. C.They are associated with shear stress. D.Vertical motion is minimal.

C. They are associated with shear stress D. Vertical motion is minimal

Faults are examples of what kind of rock deformation? Choose one: A. ductile B. plastic C. elastic D. brittle E. vitric

D. Brittle

This type of folding is stair-step-like fold ?

Monocline

This type of folding conve-upward through ?

Syncline

Which is associated with folding ? compressional stress bending of geologic materials ductile deformation brittle deformation

brittle deformation

Which is associated with folding ? compressional stress bending of geologic materials ductile deformation brittle deformation

compressional stress bending of geologic materials ductile deformation

Reverse plate boundaries are associated with what plate boundaries ?

convergent

Which of the following is associated with folding ? earthquakes fracturing brittle deformation ductile deformation

ductile deformation

Which is associated with faulting ? earthquakes fracturing brittle deformation ductile deformation

earthquakes fracturing brittle deformation

How do you recognize faults in the field ? jointing slickensides offset of layers on opposite sides of the fault development of drag folds along the fault interface shattered rock powdered rock

slickensides offset of layers on opposite sides of the fault development of drag folds along the fault interface shattered rock powdered rock

Select statements true of ductile deformation in solids. Note that ductile deformation is also called plastic deformation. A.Ductile deformation usually occurs at great depths and high temperatures. B.Ductile deformation is usually preceded by small amounts of elastic deformation. C.During ductile deformation, rocks can break or crack into pieces. D.During ductile deformation, rocks can fold or bend.

A. Ductile deformation usually occurs at great depths and high temperatures D. During ductile deformation, rocks can fold or bend

How is a fault different from a joint ? A. Faults are fractures along which displacement has occurred; displacement does not occur along joints. B. Faults are joints that are larger than a square meter in area. C. Joints are fractures along which displacement has occurred; displacement does not occur along faults. D. There is no difference; the two terms are synonymous.

A. Faults are fractures along which displacement has occurred; displacement does not occur along joints

Which of the following statements about stress is true? A. It may have different magnitude in different directions. B. It is the same as force. C. It is the change in shape produced by strain. D. It is the same as pressure.

A. It may have different magnitude in different directions

Geologists describe the movement of strike-slip faults as being either left-lateral or right-lateral. To tell the difference, imagine that you are standing on one side of the fault trace, and your friend is standing on the opposite side. You are both facing each other. When the fault moves, you will see your friend either move to your left (left-lateral motion) or to your right (right-lateral motion), depending on the direction of displacement. Watch the Strike-Slip Fault topic of the Faults Animation. Which of the following terms correctly describes the motion across the fault? Choose one or more: A.left-lateral motion B.strike-slip motion C.right-lateral motion D.dip-slip motionE.The hanging-wall block moves up, and the footwall block moves down.

A. Left-lateral motion B. Strike-slip motion

Based on looking at the offset of the beds, which type of fault is this? A. thrust fault B. strike-slip fault C. unconformity D. normal fault

A. Thrust fault

What is associated with dip-slip faults ? Results in crustal lengthening or shortening Crust is shortened or lengthened Associated with shear stress Motion is primarily horizontal

Results in crustal lengthening or shortening Crust is shortened or lengthened

Which statements are true about brittle deformation ? A.Brittle deformation can be preceded by small amounts of elastic deformation. B.During brittle deformation, rocks can break or crack into pieces. C.During brittle deformation, rocks can fold or bend. D.Brittle deformation usually occurs at great depths and high temperatures.

A. brittle deformation can be preceded by small amounts of elastic deformation B. During brittle deformation, rocks can break or crack into pieces

Ductile deformation results in a change of the shape of solids without breaking them. This can also be said of elastic deformation. Watch both the Elastic Deformation and Ductile Deformation topics in the Reock Deformation Animation, and compare the two types of deformation. How is ductile deformation different from elastic deformation? A.Once the stress is removed, rocks that have undergone ductile deformation retain their new shape. B.Ductile deformation requires internal fracturing of the rock, whereas elastic deformation does not. C.Once the stress is removed, rocks that have undergone ductile deformation return to their original shape. D.Ductile deformation can result in tight folds, whereas elastic deformation usually terminates in brittle deformation rather than tight folding.E.Ductile deformation results in folds, whereas elastic deformation results in faults.

A. once the stress is removed, rocks that have undergone ductile deformation reatin their new shape D. Ductile deformation can result in tight folds, whereas elastic deformation rather than tight folding

Which statements are true about monoclines? Choose one or more; A.Monocline formation is influenced by underlying structures. B.They are step-shaped folds. C.They are the result of ductile deformation. D.They form from compressional stress.

A.Monocline formation is influenced by underlying structures. B.They are step-shaped folds. C.They are the result of ductile deformation. D.They form from compressional stress.

Which statements are true about normal faults ? A.They are associated with tensional stress. B.The hanging wall moves down relative to the footwall. C.Their motion is dip-slip. D.The result is shortening of the crust.

A.They are associated with tensional stress. B.The hanging wall moves down relative to the footwall. C.Their motion is dip-slip.

Which statements are true about synclines? Choose one or more: A.They are the result of ductile deformation. B.The limbs dip toward the hinge. C.They have an arch-like shape. D.They form from compressional stress.

A.They are the result of ductile deformation. B.The limbs dip toward the hinge. D.They form from compressional stress.

Which statements are true of anticlines? Choose one or more: A.They form from compressional stress. B.The limbs dip toward the hinge. C.They are the result of ductile deformation. D.They have an arch-like shape.

A.They form from compressional stress. C.They are the result of ductile deformation. D.They have an arch-like shape.

This type of folding is convex-upward arch ?

Anticline

When a fault scarp forms, it exposes the fault plane at the surface. Why is a normal fault plane more pristinely exposed than a reverse fault plane? Choose one:A. A normal fault always experiences more relative motion than a reverse fault. B. A reverse fault results in a fault scarp in which the hanging wall overhangs the surface of the footwall block, causing collapse of the scarp. C. Actually, neither a normal nor reverse fault exhibits a fault scarp. D. A normal fault is always at a steeper angle and therefore is less prone to fault-scarp collapse.E. A normal fault results in a fault scarp in which the hanging wall overhangs the surface of the footwall block which tends to better preserve the exposed fault plane.

B. A reverse fault results in a fault scarp in which the hanging wall overhangs the surface of the footwall block, causing collapse of the scarp

Sideling Hill, in western Maryland, is a northeast-southwest-trending ridge underlain by Paleozoic sandstone, shale, and coal. This fold formed due to the collision of Africa with North America. Note that the compass shown over the highway points approximately north. What kind of fold is this ? Choose one: A. anticline B. syncline C. monocline D. homocline

B. Syncline

View the sequence on normal faults. Which of the following happens at a normal fault? Choose one or more: A.The hanging wall moves up relative to the footwall. B.The hanging wall moves down relative to the footwall. C.The motion of the crustal blocks is referred to as strike-slip. D.The crust experiences extension.E.The footwall moves down relative to the hanging wall.

B. The hanging wall moves down relative to the footwall D. The crust experiences extension

Infer which of these solids is most likely to deform elastically under stress. A. playdough B. a rubber band C. a paper clip D. a ceramic plate

B. a rubber band

Identify the result of continental collision. Choose one: A. rifting B. subduction C. volcanism D. orogenesis

D. orogenesis

Normal faults are associated with what plate boundaries?

Divergent

What plate boundary(s) are associated with strike-slip faults ?

Transform