Deck 34: Faults, Folds, and Landscapes

Question 1

To describe the nature and orientation of structures, the _____ is the compass direction of the line of intersection between a rock layer and a horizontal plane.

A) dip
B) slope angle
C) outcrop
D) strike

Answer 1

D

Question 2

A fracture in the Earth's crust that shows no displacement between rock layers on either side of the fault is called a:

A) fault plane
B) fault scarp
C) joint
D) fault

Answer 2

C

Question 3

The block of rock below the fault plane is termed:

A) hanging wall
B) footwall
C) underhang wall
D) basement rock

Answer 3

B

Question 4

It is difficult to identify outcrops that reveal reverse faulting because the overlying hanging wall has usually collapsed, weathered, and eroded. Another easy way to identify a reverse fault is by locating:

A) areas of older rocks overlying younger rock
B) a vertical scarp face
C) areas of younger rocks overlying older rock
D) a depression where the hanging wall was once located

Question 5

When the block above a low-angle fault plane moves up, it produces a _____ fault.

A) normal
B) reverse
C) strike-slip
D) thrust

Question 6

A linear valley produced from tensional forces is called a _____.

A) rift valley
B) footwall
C) anticline
D) syncline

Question 7

What type of stress is imposed on a rock body to produce horsts and grabens?

A) compressional forces
B) tensional forces
C) shear forces
D) oblique forces

Question 8

If the San Andreas Fault continues its current motion, the city of Los Angeles will eventually lie next to San Francisco. The motion would best be described as a:

A) right-lateral strike-slip fault
B) left-lateral strike-slip fault
C) reverse faulting
D) normal faulting

Question 9

An anticline has:

A) older rocks exposed along its axial plane
B) dipping beds away from the axial plane
C) dipping beds toward the axial plane
D) horizontal beds on both side of the axial plane

Question 10

Many times it is difficult to see the layers of the Earth firsthand. Therefore, scientists take strike and dip measurements along the surface of the Earth to determine what the layers look like at depth. Understanding that the fold axis is an imaginary hinge at the apex of a fold, a geologist would know that the presence of an anticline exists when multiple layers are exposed and:

A) the rock layers dip outward or away from the fold axis and rock layers become progressive older as you move away
B) the rock layers dip inward or toward the fold axis and rock layers become progressively younger as you move away
C) the rock layers dip outward or away from the fold axis and rock layers become progressively younger as you move away
D) the rock layers dip inward or toward the fold axis and rock layers become progressively older as you move away

Question 11

When studying a geologic map, a geology student notices that the rock layers make a "U-shaped" pattern, a band of old rocks are found near the axial plane, and the rocks become progressively younger tracing the layers from the plane outward. The geology student concludes he is looking at a:

A) alternating synclines and anticlines
B) plunging syncline
C) plunging anticline
D) cannot tell with the evidence provided

Question 12

Field evidence that may help to determine if the beds are overturned would be:

A) beds on opposite sides of the axial plane are dipping in the same direction
B) beds alternate between dipping toward the axial plane and then dipping away from the adjacent axial plane
C) beds are horizontal
D) impossible to determine

Question 13

Regional deformation may also be termed all of the following EXCEPT:

A) epeirogeny
B) orogeny
C) diastrophism
D) crustal warping