Deck 3: Plate Tectonics: The Unifying Theory of Geology

Question 1

Where is new lithosphere created?

A) convergent plate boundaries
B) divergent plate boundaries
C) transform fault boundaries
D) convergent plate boundaries and divergent plate boundaries

Answer 1

B

Question 2

What is the name of the large supercontinent that existed 200 million years ago when all the continents were together?

A) Rodinia
B) Pangaea
C) San Andreas

Answer 2

B

Question 3

Complete the following sentence. Lithospheric plates are created where they____________.

A) converge
B) separate
C) subside
D) all of these

Answer 3

D

Question 4

About when did the HMS Challenger expedition take place?

A) 1490's
B) 1950's
C) 1870's
D) 1980's

Question 5

Which type(s) of plate boundaries indicate(s) the direction of relative plate motions?

A) convergent plate boundaries
B) divergent plate boundaries
C) transform fault boundaries
D) all of the above

Question 6

-What type of plate boundary is shown in the diagram?

A) a continent collision
B) a spreading center
C) a subduction zone
D) a transform fault

Question 7

-Which of the following locations could be represented by the diagram?

A) the east coast of Africa
B) the west coast of South America
C) the east coast of North America
D) the west coast of Europe

Question 8

"Oblique" boundaries combine convergent or divergent motion with ________ motion.

A) transform
B) spreading
C) vertical
D) none of the above

Question 9

-What type of plate boundary is depicted in the cross section?

A) convergent
B) transform
C) divergent
D) cannot tell from the information given

Question 10

New oceanic lithosphere forms at

A) convergent plate boundaries.
B) divergent plate boundaries.
C) transform plate boundaries.

Question 11

The Red Sea represents a ___ plate boundary.

A) transform
B) divergent
C) convergent

Question 12

Which of the following mountain ranges did not form as a result of continent collision?

A) Appalachian Mountains
B) Andes Mountains
C) Himalayas

Question 13

Earthquakes are associated with which of the following types of plate boundaries?

A) divergent and convergent
B) convergent and transform
C) convergent, divergent, and transform

Question 14

Which of the following features is not associated with a divergent plate boundary?

A) deep-sea trenches
B) earthquakes
C) mid-ocean ridges

Question 15

Which of the following features represents the cold, downwelling part of the mantle convection system?

A) mantle plumes
B) spreading centers
C) subduction zones

Question 16

The chain of volcanoes that forms at an ocean-ocean convergent plate boundary is referred to as a(n) ___ arc.

A) continental
B) subduction
C) island

Question 17

The questions refer to this cross section, which depicts magnetized oceanic crust at a spreading center. The "+" symbol indicates positive (normal) magnetic anomalies; the "-" symbol indicates negative (reversed) magnetic anomalies.

-How fast are points C and D spreading apart from each other?

A) about 20 millimeters/year
B) about 100 millimeters/year
C) about 50 millimeters/year
D) about 200 millimeters/year

Question 18

"Normal" magnetized crust at the spreading center formed during the ________ epoch.

A) Brunhes
B) Gauss
C) Gilbert
D) Matuyama

Question 19

Which of the following statements comparing rates of plate motion determined from seafloor magnetic anomalies and the global positioning system (GPS) is correct?

A) Rates of plate motions over the past decade are much faster than rates over the past several million years.
B) Rates of plate motions over the past decade are very similar to rates over the past several million years.
C) Rates of plate motions over the past decade are much slower than rates over the past several million years.

Question 20

Which of the following statements is true?

A) Most of the continental crust is older than the oceanic crust.
B) Most of the oceanic crust is older than the continental crust.
C) Continental crust and oceanic crust are approximately the same age.

Question 21

Lines on a map of the seafloor that connect rocks of the same age are called

A) isograds.
B) isotopes.
C) isochrons.

Question 22

What is the name of the ancient ocean that surrounded Pangaea?

A) Panthalassa
B) Pangaean Sea
C) Laurasia

Question 23

A tectonic plate that is being subducted along much of its boundary tends to move ___ a tectonic plate that is not being subducted.

A) slower than
B) at the same rate as
C) faster than

Question 24

Pangea was the first supercontinent.

Question 25

Which is an appropriate speed for mantle convection?

A) centimeters per year
B) meters per year
C) kilometers per year
D) none of these

Question 26

Frictional forces cause plates that are subducting along large fractions of their margins to move more slowly than those that are not subducting.

Question 27

Most geoscientists have concluded that plate recycling takes place through whole-mantle convection rather than stratified convection.

Question 28

What is the approximate depth of the boundary between the upper mantle and the lower mantle?

A) 100 kilometers
B) 700 kilometers
C) 2900 kilometers
D) 5300 kilometers

Question 29

Volcanic activity in Hawaii is attributed to which geologic phenomenon?

A) sea-floor spreading
B) subducting plates
C) transform motion
D) mantle plumes

Question 30

What is the nature of mantle motion underneath mid-ocean ridges?

A) focused columns of sinking mantle
B) focused columns of rising mantle
C) broad, spread out, sinking mantle
D) broad, spread out, rising mantle

Question 31

Supporters of the stratified mantle convection hypothesis believe a rapidly convecting lower mantle drives slower, more sluggish convection in the upper mantle.