Deck 11: Cracks, crags, and Crumples: Crustal Deformation and Mountain Building

Question 1

A body of rock affected by tensile stress will likely undergo ____________.

A)shortening
B)stretching
C)shear strain

Answer 1

B

Question 2

Earthquakes only occur ____________ the brittle/ductile transition depth.

A)above
B)below
C)at or near

Answer 2

A

Question 3

Normal,reverse,and thrust are all examples of ____________ faults.

A)strike-slip
B)dip-slip
C)oblique-slip

Answer 3

B

Question 4

An episode of mountain building is termed a(n)____________.

A)orogeny
B)phylogeny
C)aureole
D)slickenside

Question 5

Force per unit area is termed ____________.

A)stress
B)strain
C)power
D)work

Question 6

Mt.Everest,the tallest mountain in the world,is located on the continent of ____________.

A)Africa
B)Asia
C)North America
D)Europe

Question 7

In a ____________ fault,the fault plane is greater than 35° from horizontal and the hanging-wall block moves upward relative to the footwall block.

A)detachment
B)normal
C)reverse
D)thrust

Question 8

Within a platform,sedimentary rocks always have a horizontal orientation.

Question 9

A hot body of rock is more likely to exhibit ____________ than is a cold body of rock.

A)brittle behavior
B)ductile behavior

Question 10

The distinction between joints and faults is that ____________.

A)faults are joints that are greater than one square meter in areal extent
B)faults are fractures along which displacement has occurred;displacement does not occur along joints
C)joints are fractures along which displacement has occurred;displacement does not occur along faults
D)there is no distinction;the two terms are synonymous

Question 11

A body of rock affected by compressive stress will likely undergo ____________.

A)shortening
B)stretching
C)shear strain

Question 12

A body of rock to which a sudden,rapid stress has been applied is more likely to exhibit ____________ than is a body of rock subjected to a gradually applied stress.

A)brittle behavior
B)ductile behavior

Question 13

A polished surface produced by scraping of rock along a fault is termed a(n)____________.

A)orogeny
B)phylogeny
C)aureole
D)slickenside

Question 14

Change in shape,induced by stress,is termed ____________.

A)plastic deformation
B)pressure release
C)strain
D)metamorphosis

Question 15

Right lateral and left lateral are both examples of ____________ faults.

A)strike-slip
B)dip-slip
C)oblique-slip

Question 16

A joint always occurs as a single,isolated plane within a rock.

Question 17

Movement along faults often produces sharply angled rock fragments termed ____________.

A)fault gouge
B)rock flour
C)fault breccia
D)slickensides

Question 18

A body of rock under high pressure is more likely to exhibit ____________ than is a body of rock at low pressure.

A)brittle behavior
B)ductile behavior

Question 19

Shear stress at sufficient depth within a fault plane can induce ductile shear,forming a fine-grained metamorphic rock named ____________.

A)ignimbrite
B)gneiss
C)mylonite
D)migmatite

Question 20

Most fault surfaces,like joints,are roughly planar in orientation.

Question 21

Tectonic foliation,such as elongation of quartz grains,always occurs parallel to the original bedding plane of a body of rock.

Question 22

In a ____________ fault,the fault plane is nonvertical and the hanging-wall block moves downward relative to the footwall block.

A)detachment
B)normal
C)reverse
D)thrust

Question 23

A geologist's compass differs from the more widely known orienteering compass in that the geologist's compass ____________.

A)possesses an inclinometer,allowing the user to measure dip and plunge angles
B)contains a barometer that warns the geologist of approaching storms
C)can chemically analyze rock samples in the field
D)needle points directly toward geographic north rather than geomagnetic north

Question 24

On a geologic map,if the contacts between sedimentary rock units form a bull's-eye pattern of concentric circles,with the oldest unit in the center,the underlying structure is a(n)____________.

A)anticline
B)basin
C)dome
D)syncline

Question 25

Deformation brought on by orogeny can ____________.

A)metamorphose rock
B)produce folds in rock
C)produce faulting in rock
D)All of the above are correct.

Question 26

A fold shaped like an elongate trough is a(n)____________.

A)anticline
B)basin
C)dome
D)syncline

Question 27

A fold shaped like an right-side-up bowl is a(n)____________.

A)anticline
B)basin
C)dome
D)syncline

Question 28

On a geologic map,if the contacts between sedimentary rock units form a bull's-eye pattern of concentric circles,with the youngest unit in the center,the underlying structure is a(n)____________.

A)anticline
B)basin
C)dome
D)syncline

Question 29

The sides of a fold,where curvature is at a minimum,are termed ____________.

A)branches
B)limbs
C)axial planes
D)hinges

Question 30

____________ may help a geologist recognize a fault.

A)Displacement
B)Fault scarps
C)Breccia
D)All of the above are correct.

Question 31

In a ____________ fault,the fault plane is less than 35° from horizontal and the hanging-wall block moves upward relative to the footwall block.

A)detachment
B)normal
C)reverse
D)thrust

Question 32

A fold shaped like an elongate arch is a(n)____________.

A)anticline
B)basin
C)dome
D)syncline

Question 33

Motion along all faults is either strike slip or dip slip;combinations of these two types of displacement are never found together in a single fault.

Question 34

Orogenesis (mountain building)leads to the production of ____________.

A)metamorphic rocks only
B)igneous rocks only
C)sedimentary rocks only
D)All of the above are correct.

Question 35

The central portion of high curvature on a fold is termed the fold ____________.

A)limb
B)hinge
C)midsection
D)thorax

Question 36

Mountain ranges are important sites for the formation of igneous and metamorphic rocks,but do not have any apparent relationship with the formation of sedimentary rocks.

Question 37

In the map below,the vertical,north-south trending fault is a ____________ fault.

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

Question 38

A fold shaped like an upside-down bowl is a(n)____________.

A)anticline
B)basin
C)dome
D)syncline

Question 39

Normal faults assume a more shallow dip angle with depth;when the fault plane becomes nearly horizontal,these faults are termed ____________.

A)thrusts
B)folds
C)detachments
D)decollements

Question 40

It is possible for offset along an oblique-slip fault to have both ____________ and ____________ components.

A)normal;reverse
B)right-lateral;left-lateral
C)normal;left-lateral

Question 41

Mountain ranges are associated with modern and ancient convergent-plate boundaries,but do not form in association with either divergent- or transform-plate boundaries.

Question 42

Regions where Precambrian metamorphic rocks are exposed at the surface are termed ____________.

A)shields
B)platforms
C)convergent margins

Question 43

Valleys and hillsides carved by glaciers are generally more ____________ in comparison to those produced by rivers and streams.

A)steep sided
B)shallow sided

Question 44

Continental crust is typically 35-km thick,but may be up to ____________ thicker under mountain ranges.

A)20%
B)50%
C)100%
D)200%

Question 45

On a geologic map,if the contacts between sedimentary rock units form a series of parallel lines,with the youngest unit in the center,the underlying structure is a(n)____________.

A)anticline
B)basin
C)dome
D)syncline

Question 46

The outer portion of a craton,where deformed rocks are covered by sediments,is termed the ____________.

A)shield
B)platform
C)convergent margin

Question 47

The balance between the weight of a mountain range and the buoyancy provided by the underlying mantle is termed ____________.

A)punctuated equilibrium
B)homeostatic equilibrium
C)isostatic equilibrium
D)osmotic equilibrium

Question 48

Theoretically,there is no reason why mountains substantially taller than Mt.Everest might not one day arise on Earth.

Question 49

Regions of continents that have not been subjected to orogeny during the past one billion years are termed ____________.

A)exotic terranes
B)accreted terranes
C)cratons

Question 50

Nearly all of the present mountain ranges are the products of single orogenic events.