Deck 9: Mountains

Question 1

If you went to the Andes Range off the west coast of South America, you would be able to see the mountains are composed predominantly of volcanic and plutonic rocks formed by ________________ at a continental margin.

Answer 1

Subduction

Question 2

Weathering associated with the erosion of the Himalayas has coincided with what global climate change because carbon dioxide was removed from the atmosphere?

Answer 2

cooling

Question 3

If a rock folds with little or no fracturing, this indicates that the rock deformed in a(n) ____________________ manner.

Answer 3

plastic

Question 4

The Appalachian Mountains were initially thought to be the size of the Himalayas but have eroded allowing them to become light and rise due to what process? ____________________.

Question 5

When two continents collide, one continent may be forced beneath the other in a process called ____________________.

Question 6

Rock that is caught at the junction of two converging plates is deformed by _________ stress.

A) divergent
B) tensional
C) compressive
D) shear

Question 7

If you are in the field and see a fold where the layers in the shape of a "U," what type of fold have you observed?

Question 8

A(n) ____________________ is a sedimentary basin formed by downward flexing of continental crust.

Question 9

Tectonic ____________________ creates different types of geologic structures, produced by rock deformation.

Question 10

If you are in the field and see a fold where the layers in the shape of a rainbow, what type of fold have you observed?

Question 11

A geologist would expect rocks, such as shale, limestone, and marble, tend to deform in a(n) ____ manner when stress is applied because these rocks are softer and behave differently to stress than rocks like granite.

A) brittle
B) fracture
C) plastic
D) fragile

Question 12

A sedimentary basin between the oceanic trench and the magmatic arc is called a(n) ____________________.

Question 13

In a fault, the hanging wall has moved downward relative to the footwall due to what specific type of stress? _____________

A) Compression
B) Tension
C) Shearing
D) None of the above

Question 14

Tectonic stress creates three major types of structures: folds, faults, and ____.

A) limbs
B) domes
C) basins
D) joints

Question 15

The island arcs formed in the Pacific Ocean basin were made because two ______ plates carrying oceanic crust converged.

Question 16

A rock has a greater tendency to become plastic if the temperature does what? ____________

Question 17

If you visit the Himalaya Range, you are looking at the location where _________ smashed into Asia in a continent-to-continent collision.

Question 18

The term ____________________ refers to the process of mountain building.

Question 19

The Andes Mountains consists predominantly of ____________________ rocks because this range was formed in a subduction zone that created numerous volcanoes.

Question 20

If a rock experiences substantial stress in the form of compression, what specific type of geologic structure would you expect to see in the field?

A) Joint
B) Fault
C) Fold
D) Basin

Question 21

A wedge-shaped block of rock that drops downward between a pair of normal faults is a(n) ____.

A) horst
B) anticline
C) graben
D) syncline

Question 22

A sedimentary basin between a trench and an island arc is called a ____________

A) Forearc basin
B) Backarc basin
C) Middle-arc basin
D) Double-trench

Question 23

A fold with one tilted axial surface and one limb facing downward is ____.

A) recumbant
B) overturned
C) symmetrical
D) asymmetrical

Question 24

Seafloor sediment and oceanic crust pieces are scraped off a subducting plate and accumulate in the ____ complex.

A) forearc
B) subduction
C) island arc
D) orogeny

Question 25

If a similar plate to the Indian Plate 50 million years ago smashed into the East Coast of North America, what type of process would occur?

A) jointing
B) underthrusting
C) subduction
D) spreading

Question 26

Rock often moves repeatedly along many faults because ____.

A) faults always lie over shallow bodies of hot magma
B) all faults lie along tectonic plate boundaries
C) faulting is a strong indication that rock in the region is distorting plastically
D) tectonic stress commonly continues to be active in the same place over long periods of time

Question 27

The belt of rocks that is deformed during mountain building is called a(n) ____.

A) fault
B) fold
C) orogen
D) joint

Question 28

The underthrusting of a plate under a continental plate such as India under Tibet will cause what type of mountains to be uplifted?

A) Volcanic mountains
B) Tallest elevation mountains above sea level
C) Greatest total relief mountains from the base of the ocean floor to the summit
D) Short mountains

Question 29

Normal faults, grabens, and horsts are common _______ because this creates a type of stress known as tension.

A) at convergent boundaries
B) where the crust is being pulled apart
C) at hot spots
D) along transform plate boundaries

Question 30

A normal fault occurs as a result of ____.

A) extensional stress stretching Earth's crust
B) crustal shortening
C) the hanging wall moving upward relative to the footwall
D) plastic behavior of rock

Question 31

The Andes Mountains contain extensive ____ rocks on both sides of the mountains that formed from the erosion of the rising peaks.

A) igneous
B) sedimentary
C) metamorphic
D) granite

Question 32

A joint is a fracture in the rock where what action has not occurred?

A) either side of the fracture has slipped
B) both sides of the fracture does not slip
C) either side of the fracture has moved horizontally past each other
D) one side of the fracture has moved many kilometers over the footwall

Question 33

A syncline _________.

A) always forms mountain peaks
B) always forms mountain valleys
C) forms as a part of a sequence of folds during crustal extension
D) is the portion of a fold that arches downward

Question 34

If a rock experiences stress that is added very slowly and at high pressure, what end result will occur?

A) brittle fracture
B) plastic deformation
C) confining stress
D) confining pressure

Question 35

A slip is ____.

A) the distance that rocks on opposite sides of a fault have moved
B) an elliptical anticlinal feature
C) a wedge-shaped block of rock that drops downward between a pair of faults
D) blocks of rock between down-dropped grabens

Question 36

The Andes Mountains were formed by convergence of a plate carrying ____ crust with a plate carrying ____ crust.

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

Question 37

As the Juan de Fuca plate subducts under the North American plate, what specific type of margin would a geologist state that this boundary represents?

A) underthrusting
B) a Himalayan margin
C) an Andean margin
D) an island arc

Question 38

The oldest layer of a basin is found in what part of a basin? _________________________

A) Top
B) Bottom
C) Middle
D) None of the above

Question 39

Prior to the formation of the Himalayas, a(n) ____ zone initially formed at the Asian margin.

A) transform
B) subduction
C) divergent
D) island arc

Question 40

A circular or elliptical anticline structure called a basin is formed by what specific type of stress?

A) dome
B) basin
C) mountain
D) valley

Question 41

The formation of the Himalayas coincided with ____.

A) global cooling
B) global warming
C) production of large amounts of carbon dioxide
D) a mass extinction

Question 42

The Himalayas were formed ____.

A) by the convergence of two oceanic plates
B) by the convergence of two continental plates
C) by the convergence of an oceanic plate with a continental plate, followed by continent-continent collision
D) at a divergent plate boundary where oceanic crust was separating from continental crust

Question 43

The modern Himalayas continue to grow as a plate carrying oceanic crust subducts beneath a plate carrying continental crust.

Question 44

Where two continental plates converge, compressional stress squeezes rocks, forming folds and normal and graben faults.

Question 45

A backarc basin is formed during the formation of island arcs.

Question 46

A subduction complex contains slices of continental crust scraped from the top of a subducting plate.

Question 47

A thrust fault is a reverse fault that is nearly vertical because the angle of slippage is very high.

Question 48

Extensional stress at a divergent plate boundary produces normal faults and grabens.

Question 49

The rising of the Himalayas coincided with global warming because excessive carbon dioxide was added to the atmosphere due to weathering of bedrock.

Question 50

The Appalachian Mountains in the United States were formed by collision between ____.

A) an oceanic plate and a continent
B) two continents
C) two oceanic plates
D) an oceanic plate and a continent, followed by a continent-continent collision

Question 51

Throughout its life cycle, a mountain continually rises due to isostasy.

Question 52

The Andes developed from a convergence between a tectonic plate carrying oceanic crust and another plate carrying continental crust.

Question 53

The Indian subcontinent was originally part of ____ 200 million years ago.

A) Laurasia
B) Nuna
C) Rodinia
D) Gondwana

Question 54

If a fold is overturned, extreme compression would have been the type of stress has been applied to cause it to turn over.

Question 55

If fossils of marine organisms are found in Himalayan sedimentary rock toward its summit, that is an indicator that this region was once an ocean.

Question 56

One reason why the Himalayas contain Earth's highest peaks is that the entire plateau lies at such a high elevation.

Question 57

Island arcs are abundant in the ____, where convergence of oceanic plates is common.

A) Atlantic Ocean
B) Indian Ocean
C) Antarctic Ocean
D) Pacific Ocean

Question 58

In order for island arc to form, two diverging oceanic plates must be separating from one another.

Question 59

The Himalayas are the world's highest mountain range because of extreme thinning of the Earth's crust.

Question 60

A horst is a block of rock between two joints that has moved relatively upward along normal faults.

Question 61

Explain how a subduction zone can add thickness to the Earth's crust.

Question 62

Explain how the subduction of the Indian Plate under Tibet transitioned into a continent-to-continent collision region.

Question 63

Discuss how the Farallon Plate transported oceanic crust to parts of California mountain ranges.

Question 64

Explain how the Lewis Overthrust fault is a prime example of a thrust fault.

Question 65

Explain how time affects the way stress impacts a rock.

Question 66

Explain how a magmatic activity can add thickness to the Earth's crust.

Question 67

Explain how faults, folds, and joints differ.

Question 68

Explain how mountains impact plant and animal habitats.   Provide an example of an organism that relies on elevation for its habitat.

Question 69

Explain how the speed of plate movement can impact plate collisions at a subduction zone.

Question 70

Explain the relationship of horsts and grabens to normal faults and identify what specific type of stress causes them to form.

Question 71

Explain how compressive tectonic forces can add thickness to the Earth's crust.

Question 72

Explain what is the difference between an Andean margin and a continent-to-continent margin.

Question 73

Explain how pressure affects the way stress impacts a rock.

Question 74

Explain how humans have impacted mountain ecosystems.

Question 75

Explain how the nature of a rock (meaning its rock type) affects the way stress impacts a rock.

Question 76

Explain how igneous, sedimentary, and metamorphic rocks all exist in the Himalayas.

Question 77

Explain how faults are important to engineering, mining, and quarrying.

Question 78

Explain how temperature affects the way stress impacts a rock.

Question 79

Explain how basalt turned into andesitic- and granitic-based volcanoes and plutons in the Andes at its subduction zone.

Question 80

Explain the process by which the hydrologic cycle is instrumental in eroding mountain ranges.