Deck 7: Plate Tectonics: a Scientific Theory Unfolds

Question 1

The former late Paleozoic super continent is known as ________.

A) Pandomonia
B) Pancakea
C) Pangaea
D) Panatopia

Answer 1

C

Question 2

In the early part of the twentieth century, ________ argued forcefully for continental drift.

A) Karl Wagner
B) Peter Rommel
C) Alfred Wegener
D) Bill Kohl

Answer 2

C

Question 3

The ________ is (are) a logical evolutionary analog of the African Rift Valleys ten million years from now.

A) Ural Mountains
B) San Andreas fault
C) Peru-Chile trench
D) Red Sea

Answer 3

D

Question 4

New oceanic crust and lithosphere are formed at ________.

A) divergent boundaries by submarine eruptions and intrusions of rhyolitic magma
B) convergent boundaries by submarine eruptions and intrusions of rhyolitic magma
C) divergent boundaries by submarine eruptions and intrusions of basaltic magma
D) convergent boundaries by submarine eruptions and intrusions of basaltic magma

Question 5

Which of the following statements apply to the asthenosphere, but not the lithosphere?

A) zone in the upper mantle that deforms by plastic flowage
B) cool, rigid layer of crust and upper mantle that forms the tectonic plates
C) deforms mainly by brittle fracturing and faulting
D) partial melting of rising granitic plumes produces huge volumes of basaltic magma

Question 6

Linear, magnetic patterns associated with mid-ocean ridges are configured as ________.

A) concentric circles about a rising plume of hot mantle rocks and magma
B) reversed magnetizations along the rift valleys and normal magnetizations along the ridge
C) normal and reversed magnetized strips roughly parallel to the ridge
D) normal and reversed magnetized strips roughly perpendicular to the ridge axis

Question 7

The continental drift hypothesis was rejected primarily because Alfred Wegener could not ________.

A) find geologic similarities on different continents
B) disprove competing theories that were more accepted by scientists
C) identify a mechanism capable of moving continents
D) all of the above

Question 8

________ was never proposed as evidence supporting the existence of Pangaea.

A) Geometrical fit between South America and Africa
B) Islands of Precambrian rocks along the Mid-Atlantic Ridge
C) Late Paleozoic glacial features
D) Similar fossils on different continents

Question 9

Pull-apart rift zones are generally associated with a ________ plate boundary.

A) transform
B) divergent
C) convergent
D) all plate boundaries

Question 10

Cooler, older, oceanic lithosphere sinks into the mantle at ________.

A) subduction zones along convergent plate boundaries
B) transform fault zones along divergent plate boundaries
C) rift zones along mid-ocean ridges
D) sites of long-lived, hot spot volcanism in the ocean basins

Question 11

Which of the following energy sources is thought to drive the lateral motions of Earth's lithospheric plates?

A) gravitational attractive forces of the Sun and Moon
B) electrical and magnetic fields localized in the inner core
C) export of heat from deep in the mantle to the top of the asthenosphere
D) swirling movements of the molten iron particles in the outer core

Question 12

The temperature below which magnetic material can retain a permanent magnetization is called the ________.

A) Darcy temperature
B) Vine temperature
C) Bullard point
D) Curie point

Question 13

Which of the following paleoclimatic evidence supports the idea of the late Paleozoic supercontinent in the Southern Hemisphere?

A) lithified loess (wind-blown) deposits in the deserts of Chile, Australia, and Africa
B) tillites (rocks formed by glaciers) in South Africa and South America
C) thick sediments in the Amazon and Congo deltas of South America and Africa
D) cold water fossils in the deep-water sediments of the South Atlantic abyssal plain

Question 14

A typical rate of seafloor spreading in the Atlantic Ocean is ________.

A) 2 feet per year
B) 0.1 inches per year
C) 20 feet per year
D) 2 centimeters per year

Question 15

________ was an ancient reptile that lived in South America and Africa during the late Paleozoic.

A) Granopteris
B) Monastarious
C) Glossopteris
D) Mesosaurus

Question 16

A very long-lived magma source located deep in the mantle is called a ________.

A) magma welt
B) basalt spout
C) melt well
D) hot spot

Question 17

All of the following are evidence supporting the theory of plate tectonics except for ________.

A) changes in the Moon's orbit due to shifting plates
B) ocean floor drilling
C) hot spots
D) paleomagnetism

Question 18

Today, ________ is in about the same geographic position as during late Paleozoic time.

A) India
B) South America
C) Australia
D) Antarctica

Question 19

Which one of the following most accurately describes the volcanoes of the Hawaiian Islands?

A) stratovolcanoes associated with subduction and a convergent plate boundary
B) shield volcanoes fed by a long-lived hot spot below the Pacific lithospheric plate
C) shield volcanoes associated with a mid-Pacific ridge and spreading center
D) stratovolcanoes associated with a mid-Pacific transform fault

Question 20

The ________ is an example of an active, continent-continent collision.

A) Arabian Peninsula slamming into North Africa under the Red Sea
B) westward movement of the South American plate over the Nazca plate
C) northern movement of Baja California and a sliver of western California toward the Hawaiian Islands
D) northward movement of India into Eurasia

Question 21

Deep-oceanic trenches are most abundant around the rim of the ________ ocean basin.

A) Atlantic
B) Indian
C) Arctic
D) Pacific

Question 22

Word Analysis. Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern.
A. Curie point B. paleomagnetism C. magnetic poles D. polar wandering

Question 23

________ most effectively outline the edges of the lithospheric plates.

A) Lines of active stratovolcanoes
B) Margins of the continental shelves
C) The locations of deep mantle hot spots
D) Lines of earthquake epicenters

Question 24

Early results of the Deep Sea Drilling Project clearly justified the conclusion that ________.

A) the oceans have not always contained most of Earth's water
B) the ocean basins are relatively young; most ocean basin rocks and sediments are Cretaceous or younger in age
C) Proterozoic rocks are found only as seamounts in the deepest parts of the ocean basins
D) the youngest sediments were deposited directly on the oldest seafloor basalts

Question 25

Matching. Match the plate boundary with the appropriate phrase.
A. convergent B. transform C. divergent
this boundary is normally devoid of volcanism

Question 26

A transform plate boundary is characterized by ________.

A) stratovolcanoes on the edge of a plate and shield volcanoes on the adjacent plate
B) two converging oceanic plates meeting head-on and piling up into a mid-ocean ridge
C) a divergent boundary where the continental plate changes to an oceanic plate
D) a deep, vertical fault along which two plates slide past one another in opposite directions

Question 27

Word Analysis. Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern.
A. oceanic ridge B. seafloor spreading C. arc volcanoes D. divergent

Question 28

The Aleutian Islands occur at a ________.

A) convergent boundary on a volcanic arc above a northward-subducting Pacific plate
B) transform boundary where North America has moved towards Alaska
C) divergent boundary where shield volcanoes are forming
D) convergent, continental margin with uplifted fault blocks, much like those of the Basin and Range Province

Question 29

Mount St. Helens and the other Cascade volcanoes are ________.

A) young, active stratovolcanoes built on a continental margin above a sinking slab of oceanic lithosphere
B) a row of young, active, shield volcanoes built as western North America moved over a hot spot deep in the mantle
C) old, deeply eroded stratovolcanoes built before the Pacific Ocean existed
D) old, deeply eroded, basaltic shield volcanoes built when western North America was over the present-day site of the Hawaiian hot spot

Question 30

Matching. Match the plate boundary with the appropriate phrase.
A. convergent B. transform C. divergent
plates are sliding past one another horizontally

Question 31

Deep ocean trenches are surficial evidence for ________.

A) rifting beneath a continental plate and the beginning of continental drift
B) sinking of oceanic lithosphere into the mantle at a subduction zone
C) rising of hot asthenosphere from deep in the mantle
D) transform faulting between an oceanic plate and a continental plate

Question 32

Word Analysis. Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern.
A. slab pull B. mantle drag C. ridge push D. slab suction

Question 33

Word Analysis. Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern.
A. Hawaii B. island arc C. volcanic arc D. subduction

Question 34

The modern-day Red Sea is explained by plate tectonics theory because it is ________.

A) a tiny remnant of a once immense ocean that was closed as Africa moved toward Asia
B) the site of a transform fault along which Arabia is moving away from Africa
C) a rift zone that may eventually open into a major ocean if Arabia and Africa continue to separate
D) a rare example of a two-continent subduction zone where the African continental plate is sinking under the Arabian continental plate

Question 35

Where would you drill to recover samples of the oldest basalts of the oceanic crust, which are Jurassic in age?

A) crest of the East Pacific, mid-ocean ridge
B) oceanic side of the Aleutian trench
C) just offshore from the Hawaiian Islands
D) Mid-Atlantic Ridge under Iceland

Question 36

________ first related the symmetrical magnetic patterns in seafloor basalts to seafloor spreading at a mid-ocean ridge.

A) Evans and Novak
B) Vine and Matthews
C) Matthews and Marks
D) Wegener and Wilson

Question 37

The volcanoes and deep valleys of east Africa are related to a ________.

A) continental rift along which parts of the African continent are beginning to slowly separate
B) fault allowing Arabia to slip westward past east Africa and penetrate into Turkey
C) transform fault aligned with the Red Sea carrying the Arabian and African blocks in opposite directions
D) continental collision zone between Africa and the Zagros Mountains along the southern margin of Eurasia

Question 38

Word Analysis. Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern.
A. fossil evidence B. fit of the continents C. paleomagnetism D. paleoclimates

Question 39

Which one of the following is an important fundamental assumption underlying the plate tectonic theory?

A) Earth's magnetic field originates in the outer core.
B) Earth's diameter has been essentially constant over time.
C) Radioactive decay slows down at the extreme pressures of the inner core.
D) Earth's ocean basins are very old and stable features.

Question 40

Matching. Match the plate boundary with the appropriate phrase.
A. convergent B. transform C. divergent
plates are moving apart from one another

Question 41

Matching. Match the plate boundary with the appropriate phrase.
A. convergent B. transform C. divergent
characterized by arcs of stratovolcanoes and deep-ocean trenches

Question 42

Seafloor spreading rates can be estimated if the geologic ages of the magnetic field reversals are independently known.

Question 43

The oldest rocks on the seafloor are much younger than the oldest rocks on the continents.

Question 44

Earth's radius and surface area are slowly increasing to accommodate the new oceanic crust being formed at mid-ocean ridges.

Question 45

Matching. Match the plate boundary with the appropriate phrase.
A. convergent B. transform C. divergent
the San Andreas fault

Question 46

The rate of seafloor spreading is, on the average, about one meter per year.

Question 47

During the geologic past, the magnetic field poles have generally been very close to Earth's rotational poles.

Question 48

Wegener's continental drift hypothesis was weakened because a viable mechanism for moving the continents was lacking.

Question 49

Hawaii is the oldest island of the Hawaiian Island chain.

Question 50

Iceland is a good example of an island arc, formed from an oceanic-oceanic plate collision.

Question 51

As the South Atlantic basin widens by seafloor spreading, Africa and South America are moving closer together.

Question 52

In general, rocks of the continental crust are less dense than rocks of the oceanic crust.

Question 53

Matching. Match the plate boundary with the appropriate phrase.
A. convergent B. transform C. divergent
where lithosphere is sinking into the mantle

Question 54

The oldest rocks of the oceanic crust are found in deep ocean trenches far away from active, mid-ocean ridges.

Question 55

Matching. Match the plate boundary with the appropriate phrase.
A. convergent B. transform C. divergent
the Mid-Atlantic Ridge

Question 56

Matching. Match the plate boundary with the appropriate phrase.
A. convergent B. transform C. divergent
the west coast of South America

Question 57

During various times in the geologic past, the polarity of Earth's magnetic field has been reversed.

Question 58

Matching. Match the plate boundary with the appropriate phrase.
A. convergent B. transform C. divergent
where subduction zones occur

Question 59

Matching. Match the plate boundary with the appropriate phrase.
A. convergent B. transform C. divergent
characterized by basaltic volcanism and seafloor spreading

Question 60

The volcanoes of Hawaii are localized above a deep mantle hot spot; they are not part of the East Pacific oceanic ridge.

Question 61

What is the name of the chain of volcanic islands shown in the diagram below?

Question 62

An extensive, late Paleozoic glaciation affected southern India, southern Africa and southeastern South America.

Question 63

The ________ today marks the location of the rift along which Africa separated from South America.

Question 64

Match the letter of each illustration below to the correct type of plate boundary.

A) transform B) divergent C) convergent (a) __________ (b) __________ (c) __________

Question 65

Although Alfred Wegener presented compelling evidence for his continental drift hypothesis (despite lacking a mechanism), why was the true nature of plate boundaries not determined until the 1960s? (Hint: Don't think of historical scientific developments, but rather the scope and rate of geological processes involved in plate tectonics.)

Question 66

Describe exactly what type of plate boundary is illustrated below and explain your answer.

Question 67

The San Andreas fault in California is a good example of a(n) ________ plate boundary.

Question 68

The Himalayan Mountains are the tectonic product of a collision between India and Eurasia that began in Eocene time and still continues.

Question 69

Japan and the Aleutian Islands have formed from a(n) ________ to ________ convergent boundary.

Question 70

What is the name of the volcanic mountain chain shown in the diagram below?

Question 71

During the first two decades of the twentieth century, ________ was a vigorous proponent of continental drift.

Question 72

Rifting and normal faulting are characteristic of a(n) ________ plate boundary.

Question 73

A(n) ________ is a long-lived, stationary magma source deep in the mantle, well below the base of the lithosphere.

Question 74

________, in the north Atlantic Ocean, is a volcanic island formed over a hot spot on a divergent plate boundary.

Question 75

If you could time travel back to the 1920s and meet Alfred Wegener, who was the original proponent of the continental drift hypothesis, what could you tell him about our modern idea of plate tectonics? What would you tell him regarding the structure of the Earth's interior, what evidence exists for plate tectonics, what is the relationship between volcanoes and earthquakes to plate tectonics (specifics), and what are some (if any) of the problems we still have in explaining certain features of plate tectonics?