Deck 7: Crustal Deformation and Mountain Building

Question 1

In a monocline, the upper and lower limbs of the fold _______ .

A) are vertical
B) dips in the same direction as the other limb, but at a lower angle
C) have a shallower dip in the opposite direction of the other limb
D) are horizontal

Answer 1

are horizontal

Question 2

Use the figure below to answer the following questions.


-The concepts of "stress" and "strain" are related because_______ .

A) "stress" causes "strain"
B) "strain" causes "stress"
C) compressional "stress" causes a convergent plate boundary to form
D) compressional "strain" causes a convergent plate boundary to form

Answer 2

"stress" causes "strain"

Question 3

The higher the temperature, the more likely it is that a _______rock will deform in a manner.

A) ductile
B) brittle
C) shear
D) elastic

Answer 3

ductile

Question 4

Most active faults pose a risk to society because they can potentially produce _______.

A) tsunamis
B) earthquakes
C) landslides
D) disruptions in groundwater flow

Question 5

Monoclines, anticlines, synclines and domes are all examples of_______ .

A) jointing
B) faulting
C) flow
D) foliation

Question 6

Large circular downwarped structures are called_______ .

A) basins
B) anticlines
C) domes
D) synclines

Question 7

Use the figure below to answer the following questions.


-In the figure, the stress on block 'X' is_______ .

A) shear
B) folding
C) tensional
D) compressional

Question 8

Use the figure below to answer the following questions.


-In the figure, the stress on block 'Y' is_______ .

A) shear
B) folding
C) tensional
D) compressional

Question 9

In an overturned fold, the beds have rotated _______.

A) more than 90 degrees
B) more than 45 degrees
C) more than 180 degrees
D) 100 to 150 degrees

Question 10

Folds are an example of _______.

A) elastic deformation
B) brittle deformation
C) ductile deformation
D) shear deformation

Question 11

Use the figure below to answer the following questions.


-In the figure, the stress on block 'Z' is_______ .

A) shear
B) folding
C) tensional
D) compressional

Question 12

Burial of rocks increases the confining pressure so that deeply buried rocks are more likely to _______than shallow rocks.

A) fold
B) fracture
C) deform
D) shear

Question 13

A transform fault is _______.

A) a reverse fault that steepens into a thrust fault
B) the rift bounding fault on a mid- ocean ridge
C) a dip- slip fault connecting an anticline with a syncline
D) a strike- slip fault that forms the boundary between tectonic plates

Question 14

When subjected to a differential stress, a very "brittle" material, like glass, will_______ .

A) not bend at all. It will only break
B) flow under low to moderate stress conditions
C) deform by breaking or elastic bending
D) flow or shear if the stress is large enough

Question 15

Use the figure below to answer the following questions.


-In the figure, which of the deformations appears most similar to what might be expected along a transform plate boundary?

A) original
B) X
C) Y
D) Z

Question 16

The San Andreas Fault in California and the Alpine Fault in New Zealand are examples of _______.

A) oblique- slip normal faults
B) normal faults
C) thrust faults
D) strike- slip faults

Question 17

Use the figure below to answer the following questions.


-The material in the figure exhibited_______ behavior when the folding occurred.

A) ductile
B) brittle
C) elastic
D) strong

Question 18

Use the figure below to answer the following questions.


-In the figure, which of the deformations appears most similar to what might be expected along a divergent plate boundary?

A) original
B) X
C) Y
D) Z

Question 19

The type of fold that has the two limbs at the same angle is called an_______ .

A) symmetrical fold
B) anticline
C) syncline
D) plunging fold

Question 20

Consider the below diagram of normal faulting. Which of the following statements is most likely to be true, based on the diagram?

A) There would likely be a lot of strike- slip faults in this area.
B) The land is most likely at a convergent plate boundary.
C) It is the product of extensional forces.
D) The fault is labeled as normal because almost all stresses on Earth produce this type of fault.

Question 21

Mountain building uplifts rocks against the force of gravity raising their potential energy, which requires work by the earth system. Based on the relative motion of fault blocks, what type of fault would you expect to require more energy than the others?

A) thrust
B) normal
C) strike- slip
D) There is no way of knowing based on information data given.

Question 22

An_______ is a thick accumulation of sediments and small tectonic blocks formed of material scraped off subducting oceanic lithosphere at a convergent margin.

A) accretionary- wedge complex
B) subterranean- accumulation complex
C) continental shelf, terrain complex
D) mass movement complex

Question 23

The area labeled C shows an active fault bounding the range. Which best describes the motion on the fault?

A) south side down
B) right lateral strike- slip
C) east side up
D) north side down
E) west side up

Question 24

Use this figure for the following questions:
The figure above is an oblique Google earth image from southwestern North America looking approximately north. The view approximately 50km across. The area is a classic area of normal faulting.

-This area represents what type of mountain system?

A) strike- slip mountains
B) andrean type mountains
C) fault block mountains
D) collisional orogen

Question 25

Southwestern North America contains a large area called the Basin and Range province. What is the origin of this name?

A) Ranges are uplifted horst blocks while basins formed as grabens.
B) The area is characterized by chains of volcanoes forming ranges next to basins that form valleys.
C) Folds have formed by compressional stresses along the plate margin forming ridges ranges. and valleys the basins. of the basin and range province.
D) Thrust faulting along the San Andreas fault produces linear ridges, the ranges, with intervening basinal valleys forming fault block mountains.

Question 26

Granitic batholiths typically form over time intervals of _______ These are normally formed below the surface of the earth.

A) billions of years
B) millions of years
C) tens of thousands of years
D) hundreds of thousands of years

Question 27

An_______ fault has little or no vertical movements of the two blocks.

A) strike slip
B) oblique slip
C) dip slip
D) stick slip

Question 28

The term "cordillera" comes from a word meaning _______.

A) spine
B) lowland
C) opening
D) desert

Question 29

Studies of the chemistry of rocks from arc volcanoes indicate the main source of the magma is_______ .

A) melting of the subducted mantle lithosphere
B) melting of the asthenosphere above the subducting oceanic plate by fluids acting as a flux to enhance melting
C) melting of the asthenosphere above the subducting oceanic plate by frictional heating on the subduction interface
D) melting of subducted oceanic crust

Question 30

What is the difference between a hanging wall and a footwall?

A) A hanging wall is a term referring to folds, while a footwall is a term relating to faults.
B) A hanging wall is found on a normal fault, while a footwall is found on a reverse fault.
C) A hanging wall is always motionless, while a footwall is what moves .
D) A hanging wall is the overhanging rock unit on the slant that separates the two slabs, while the footwall below the slant.

Question 31

Most granitic batholiths represent _______.

A) magmas generated in a rift system, prior to development of a passive margin
B) a deeply exhumed passive continental margin
C) a deeply exhumed forearc rock assemblage
D) the exhumed roots of a subduction related magmatic arc

Question 32

What is the modern theory for orogenesis mountain building.?

A) shrinking earth model
B) expanding earth theory
C) geosynclinal theory
D) plate tectonics theory

Question 33

What type of basin would be most likely to contain large amounts of sediments derived from a volcanic source?

A) a forearc basin
B) a strike- slip basin
C) a passive continental margin
D) a continental interior basin

Question 34

The west coast of California is underlain by rocks that represent_______ .

A) a collisional orogenic belt
B) an ancient Forearc Basin and accretionary wedge
C) an ancient volcanic arc
D) an oceanic plateau

Question 35

You are walking on the beach along the south- coast of Alaska. You see rocks cut by numerous faults that consist of basalt with evidence of eruption in the ocean, deep- water chert, mudstone, and sandstones with abundant volcanic material. What tectonic setting would you assign to these rocks?

A) forearc basin
B) continental interior basin
C) passive continental margin sequence
D) accretionary wedge

Question 36

In thrust faulting,_______ .

A) grabens develop on the footwall block
B) the crust is shortened and thickened
C) the hanging wall block slips downward along the thrust fault
D) horizontal, tensional stresses drive the deformation

Question 37

A good example of a present- day, passive continental margin is the _______ .

A) north flank of the East Pacific Rise
B) east coast of the Japanese Islands
C) west coast of South America
D) east coast of North America

Question 38

Grabens are formed by what type of faulting?

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

Question 39

Island arcs and Andean type mountains are both examples of mountains formed by_______ .

A) collisional tectonics
B) subduction
C) transform faults
D) rifting/oceanic spreading

Question 40

In an_______ fault, the hanging wall block moves up with respect to the footwall block.

A) strike slip
B) abnormal
C) reverse
D) normal

Question 41

Most geologists think the elevation of mountains above sea level is limited by earth's gravity because _______ .

A) rock cliffs are subject to gravity failure and can only be about 1km high
B) the earth's mantle is too weak to support the load of large mountains
C) thickening of the crust in mountain belts produces a weak deep crust the spreads by gravity collapse, limiting the elevation
D) rocks can never reach escape velocity

Question 42

The Tibetan plateau is high above sea level because_______ .

A) a giant fault beneath Tibet raises it up relative to adjacent areas
B) there are many active faults across Tibet that produce internal crustal thickening and uplift
C) the extrusion of East Asia has produced structures that thicken the crust under Tibet, producing regional uplift
D) crustal thickening over millions of years has produced a thick crust that stands high due to Isostasy

Question 43

Island arc systems now on the Tibet plateau record subduction prior to the collision of India with Eurasia. Geologists would map these pre- collisional arc rocks as_______ .

A) hot spot tracks
B) rift zones
C) pre- collisional transform zones
D) terranes

Question 44

What is the major difference between a subduction zone and a collisional mountain chain?

A) A subduction zone has active volcanism.
B) A subduction zone is a more advanced stage.
C) There are no mountains created in a subduction zone.
D) There is an ocean basin still present in the case of a collisional mountain chain.

Question 45

The_______ is are characterized by terrane accretion that has been active throughout most of Mesozoic and Cenozoic time.

A) southern margins of India and Australia
B) western margin of the Mid- Atlantic Ridge
C) western margin of North America
D) western margin of Africa

Question 46

Mountain building in the western margin of North America records a history of both_______ .

A) Andean type subduction and terrane accretion
B) Andean type subduction and continental collision
C) continental collision and terrane accretion
D) none of the above

Question 47

The below diagram is an example of what plate tectonic setting?

A) collisional mountain chain
B) passive margin
C) Andean margin
D) island- arc

Question 48

The Himalayas and Tibet are the archetypical example of an_______ mountain belt.

A) transform
B) Andean
C) collisional
D) continental rift

Question 49

In the interior of continents the earth's crust is typically about 40km thick and the elevation is near sea level. Most earth materials expand when heated, lowering their density. During rifting continental margins are heated but cool as sea floor spreading moves offshore from the continent. Thus, basic isostasy suggests that after rifting, a continental margin will_______ .

A) uplift
B) remain near sea level
C) subside
D) rise slowly as erosion removes uplifted rocks

Question 50

The Appalachian Mountains may have once been as lofty as the Himalayan- Tibetan Mountain belt is today. Why are they not this high now?

A) They developed a dense crustal root following collision, and isostasy forced them to sink to their present elevation.
B) They formed long ago, and erosion has beveled them to their present low elevation.
C) Opening of the North Atlantic Ocean converted lithosphere to asthenosphere beneath eastern North America, forcing eastern North America to sink to low elevations.
D) The mountains cooled following the collision, which increased the density of the of the rocks by cooling, and isostasy forced the mountains to sink.

Question 51

In what part of a subduction margin might you find rocks deposited on the abyssal plain, far from land?

A) Cratonic Basin
B) Volcanic Arc
C) Forearc Basin
D) Accretionary Wedge

Question 52

Folded limestones that are exposed high elevations in the Himalayas were originally deposited as sediments in a _______ .

A) deep ocean trench along the southern margin of India
B) marine basin between India and Eurasia
C) late Paleozoic syncline north of the Tibetan Plateau
D) Cenozoic fault basin between Africa and Arabia

Question 53

The Appalachians were formed by three phases of _______ orogeny.

A) rifting
B) Andean
C) collisional
D) transform

Question 54

The Peninsular terrane is now part of the crust of North America in southern Alaska. The dominant rock type in this terrane is intrusive igneous rock that ranges in composition from gabbro to granite and volcanic rock with a similar compositional range. Geologic evidence indicates the Peninsular terrane collided with North America during late Mesozoic time. Which of the following would be the most reasonable interpretation for the origins of the Peninsular terrane?

A) a Mesozoic island arc
B) a Mesozoic oceanic plateau
C) a Paleozoic accretionary wedge
D) a Mesozoic accretionary wedge
E) a Cenozoic forearc basin

Question 55

A widely cited theory associates active faults with earthquakes in China and Southeast Asia. This theory suggests_______ .

A) India is moving west relative to Eurasia, pulling central Asia away from East Asia
B) East Asia is moving toward the Himalaya, causing faulting and earthquakes
C) subduction beneath East Asia is pushing East Asia toward the Himalaya, forming young mountains between the Himalaya and Pacific subduction zones
D) India is plowing into the "soft underbelly" of Asia, pushing East Asia eastward

Question 56

The Sierra Nevada Mountains of California, and the Teton Mountains of Wyoming, ranges are examples of_______ .

A) isostatic uplift of crust over thickened in early Paleozoic time
B) folding, compression, and thickening of Paleozoic strata in Jurassic time
C) fault blocks uplifted by late Tertiary to Quaternary normal faulting
D) uplifted blocks bounded by Quaternary reverse faults

Question 57

The boundary between two terranes or two continents that have collided is called a _______.

A) weld
B) suture
C) join
D) stitch

Question 58

The Rocky Mountains of western North America were produced in an orogeny called the_______ .

A) Uinta orogeny
B) Absaroka orogeny
C) Laramide orogeny
D) Laurentide orogeny

Question 59

A thrust fault increases the thickness of the crust as it moves toward a continental interior in a mountain belt; yet the crust beyond the mountain front stays the same thickness. Isostasy would suggest that the area at the mountain front, where the thrust emerges, should _______over time.

A) near sea level
B) uplift
C) stay the same
D) subside

Question 60

In the interior of continents the earth's crust is typically about 40km thick and the elevation is near sea level. In an area where the crust is 20km thick, isostasy would suggest the elevation in this area would be_______ unless the density changes from one area to the other.

A) near sea level
B) below sea level
C) high mountains
D) slightly above sea level

Question 61

Carefully study the illustration below to determine the types. of geologic structures. it shows.

A) monocline
B) anticline
C) reverse fault
D) normal fault

Question 62

Changes in the shape of a rock body in response to a differential stress is called ______.

Question 63

Ocean spreading centers are highlands on the ocean floor, sometimes referred to as submarine mountains. Oceanic crust worldwide is about the same thickness so isostasy would suggest the ocean floor should be as flat as Kansas. Which of the following statements best describes the origin of these submarine mountains?

A) Compression at the ridges produce local uplift along the ridge axis.
B) The ridges represent upwelling zones from the core which produces a bulge at the earth's surface.
C) The ridges are sites of young volcanoes that produce high topography on the sea floor, like Hawaii.
D) The mantle beneath the ridges remains hot for millions of years producing an elevated region along the ridge axis because hot rocks are lower density than cold rocks.

Question 64

On the blanks provided below, fill in the name of the specific type of geologic features that have been labeled.

Question 65

What type of structure is shown below?

A) monocline
B) transform
C) syncline
D) anticline

Question 66

Refer to the figure below, captured from Google Earth, for the following questions.


-This mountain belt would be called_______ .

A) a terrane accretion mountain belt
B) a collisional mountain belt
C) an Andean mountain belt
D) fault block mountains

Question 67

An______ fault forms when the hanging wall moves down relative to the footwall.

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

Question 68

Subduction occurs when______ rocks are forced beneath rocks.

A) continental; continental
B) oceanic; continental
C) oceanic; continental or oceanic
D) continental; oceanic or continental

Question 69

Use this figure for the following questions:
The figure above is an oblique Google earth image from southwestern North America looking approximately north. The view approximately 50km across. The area is a classic area of normal faulting.

-Topographic basins like the areas labeled B in this figure are called ______.

A) joint
B) horst
C) graben
D) fracture

Question 70

Carefully study the illustration below to determine the types. of geologic structures. it shows.

A) normal fault
B) anticline
C) monocline
D) reverse fault

Question 71

Exhumed basins contain ______rocks in the center of the structure and domes contain rocks in the center.

A) younger; younger
B) older; younger
C) younger; older
D) older; older

Question 72

Orogenesis refers to the formation of______ .

A) accretionary wedges
B) mineral deposits
C) mountains
D) fault planes

Question 73

When the hinge line of a fold is not horizontal the fold is said to______ .

A) syncline
B) fracture
C) plunge
D) overturn

Question 74

Refer to the figure below, captured from Google Earth, for the following questions.


-In the above diagram what type of mountain range exists at letter C?

A) collisional mountain chain
B) fault block mountain
C) island- volcanic arc
D) continental volcanic arc

Question 75

Carefully study the illustration below to determine the types. of geologic structures. it shows.

A) monocline
B) anticline
C) normal fault
D) reverse fault

Question 76

When the differential stress exceeds the strength of the material, the material will begin to undergo ______.

A) elastic strain
B) reverse faulting
C) brittle deformation
D) overturned faulting

Question 77

Fractures in rock with no offset where there has been no motion. are called______ .

A) accretionary wedges
B) sutures
C) fractures
D) joints

Question 78

Use the figure below to answer the following questions.


-Which letter in the figure corresponds to a "fault"?

A) A
B) B
C) C
D) D

Question 79

Use the figure below to answer the following questions.


-Which letter in the figure above corresponds to a "syncline"?

A) A
B) B
C) C
D) D

Question 80

Terrane accretion generally occurs along a ______ boundary between a continental plate and an. ________ plate.

A) convergent; oceanic
B) divergent; oceanic
C) divergent; continental
D) convergent; continental