Deck 17: Earth History

Question 1

Describe the formation of Pangaea. What was the name given to the ocean that covered the rest of the planet?

Answer 1

During the Carboniferous, southern Gondwana moved over the South Pole, resulting in glaciation that produced global sea level changes. In Early Carboniferous, Gondwana moved northward, collided with Laurasia and continued accreting during the rest of the Carboniferous period. Finally, Gondwana and Laurasia came together, and Siberia collided with Kazakhstania and moved toward Laurasia, colliding with it during the Early Permian. Other continental collisions occurred during the Permian. A single enormous ocean Panthalassa surrounded Pangaea and spanned the Earth from pole to pole.

Question 2

How does the Absaroka sequence differ from the Kaskaskia sequence and what do these differences indicate for the environment of the time?

Answer 2

The Absaroka sequence, from Late Mississippian to Early Jurassic, overlies the Kaskaskia sequence from Middle Devonian to Middle Mississippian. The sequences are a result of different tectonic regimes. The Pennsylvanian rocks have cyclothems, indicating repeated rise and fall in sea levels. Ice sheets on Gondwana also grew and melted, causing sea level to subsequently rise and fall.

Question 3

Describe what happened to create the Sauk sequence from its beginning to the beginning of the Tippecanoe sequence.

Answer 3

During the Middle Cambrian, shallow seas encroached over the craton, beginning the transgressive phase of the Sauk. By Late Cambrian, the sea covered most of North America with the exception of a portion of the Canadian shield and a few large islands named the Transcontinental Arch. The Sauk Sea regressed from the craton during the Early Ordovician, and the exposed rocks were eroded resulting in a craton-wide unconformity marking the boundary between the Sauk and Tippecanoe sequences.

Question 4

Describe the four stages of the breakup of Pangaea.

Question 5

Describe the tectonic evolution of western North America beginning with the Permian and through the Mesozoic.

Question 6

What do cyclothems represent?

Question 7

Briefly describe the geologic history of the North American Cordillera.

Question 8

Describe the geologic history of the Ancestral Rockies.

Question 9

What was the Cordilleran orogeny? Briefly describe the three phases of the orogeny.

Question 10

What is the origin of greenstone belts?

Question 11

Describe the operations and sequence of Earth's systems.

Question 12

How was the style of plate tectonics different in the Archean than it is today? When did the present style of plate tectonics begin?

Question 13

Outline the history of the Alpine-Himalayan belt.

Question 14

Briefly explain the difference between the tectonic setting of shield areas during the Precambrian and since the onset of the Phanerozoic.

Question 15

What geologic evidence can be found along the eastern margin of North America of the Triassic breakup of Pangaea?

Question 16

Describe the history of the Pleistocene ice ages.

Question 17

In what two ways was the Laramide orogeny different from other orogenies?

Question 18

Why do we know very little about the planet's first 600 million years and very little about the early part of the Precambrian era?

Question 19

What tectonic event caused the Taconic and Acadian orogenies?

Question 20

How did the landmass called Laurentia come together?

Question 21

What are believed to be the causes of global transgressive and regressive cycles?

Question 22

What is a clastic wedge, such as might form during an orogeny?

Question 23

When and where did the Acadian orogeny occur?

Question 24

In what two major zones or belts has Cenozoic orogenic activity been mainly concentrated?

Question 25

What are the three main rock types that characterize Archean shield areas?

Question 26

What is the Tippecanoe sequence?

Question 27

What are mobile belts of a continent?

Question 28

What worldwide effect was caused by Gondwana moving over the South Pole during the Carboniferous Period?

Question 29

Describe the first phase of the Cordilleran orogeny.

Question 30

What is the basic difference between the Archean and the Proterozoic?

Question 31

What was the name given to the most recent episode of large-scale deformation in the Cordillera, and when did it begin?

Question 32

Name the two periods into which the Cenozoic is divided.

Question 33

When and where did the Antler orogeny occur?

Question 34

What is the origin of the present topography of the Appalachian Mountains?

Question 35

What was the Sundance Sea?

Question 36

What is the North American Cordillera?

Question 37

What caused the Alpine orogeny?

Question 38

How many major glaciation stages occurred during the Pleistocene Epoch of North America? Name them in order from oldest to youngest.

Question 39

What were three major mobile belts in North America in the Paleozoic?

Question 40

What role did microplates play in the formation of Pangaea?

Question 41

The plate tectonic activity that gave rise to orogens around much of the circum-Pacific orogenic belt was ____________________.

Question 42

The term used to represent both time and rocks is called ____________.

Question 43

During the last two million years of the Pleistocene Epoch, there have been at least ____________________ warm-cold cycles.

Question 44

The formation of the Midcontinent rift was ____________________ in time with the Grenville orogeny.

Question 45

The ____________________ orogeny that occurred in the Cordilleran mobile belt was caused by ____________________.

Question 46

The orogens along the west coasts of the Americas, the eastern margin of Asia, and the islands north of Australia and New Zealand are part of the _________________________.

Question 47

The breakup of Pangaea began during the ____________________ Period and continued through the ____________________ Period.

Question 48

Pangaea was formed from tectonic plates and ____________________.

Question 49

The first major transgression onto the North American continent is recorded in rocks of the ____________________ sequence.

Question 50

The distinctive sedimentary rocks that were deposited in the early-formed Gulf of Mexico were ____________________.

Question 51

The ____________________ forms the core of North America and is now tectonically inactive.

Question 52

The most abundant rock type deposited during the Kaskaskian sequence was ____________________.

Question 53

Erosion of the Taconic Highlands resulted in the development of a(n) ____________________ called the ____________________.

Question 54

The rock assemblage of sandstone, carbonate, and shale represents deposition on a(n) ____________________ continental margin.

Question 55

Orogeny during Late Jurassic to Cretaceous deformation, which greatly influenced the western part of North America, is called ________________ orogeny.

Question 56

The Gulf of Mexico began to form in the ____________________ Period.

Question 57

By the (Early/Middle/Late)____________________ Cambrian most of North America was covered by epeiric seas with the exception of a highland known as the _________________________.

Question 58

Continental growth during the Early Proterozoic development of Laurentia was related to ____________________ of ____________________-age cratons.

Question 59

The Early Cretaceous sedimentation in the Gulf Coastal region was related to a (transgressive/regressive) ____________________ seaway.

Question 60

The ____________________ orogeny in Europe is a mirror of the Taconic and Acadian orogenies in North America.

Question 61

The craton can be divided into two components, which are a(n):

A) mobile belt and a sub-craton.
B) sub-craton and a platform.
C) platform and a mobile belt.
D) shield and a platform.
E) epeiric sea and a platform.

Question 62

Eastern North America during the Cenozoic can be described as a(n):

A) active orogenic belt.
B) area of uplift and erosion.
C) active volcanic region.
D) flat, eroded plain.
E) major marine basin.

Question 63

Archean and Proterozoic greenstone belts formed in similar tectonic settings.

Question 64

Archean continental masses were smaller but of the same configuration as those of the modern world.

Question 65

During the entire Paleozoic, the western margin of North America could be described as:

A) tectonically active with the development of numerous mobile belts.
B) a passive margin with only localized mountain building events.
C) a passive margin with no evidence of orogeny.
D) an active margin with thick carbonate platforms.
E) a zone of active volcanism.

Question 66

The Mesozoic Era orogenies of the Cordillera:

A) progressively affected areas from west to east.
B) progressively affected areas from east to west.
C) involved only deformation and no magmatism.
D) involved only magmatism and no deformation.
E) A and C

Question 67

The Himalayan Range formed as a result of:

A) oceanic-oceanic plate collision.
B) continental-continental transform faulting.
C) continental-continental collision.
D) oceanic-continental collision.
E) continental-oceanic subduction.

Question 68

The Permian-Triassic orogenic event that occurred with the collision of an island arc with the western margin of North America is called the:

A) Antler orogeny.
B) Cordilleran orogeny.
C) Sonoma orogeny.
D) Franciscan orogeny.
E) Western orogeny.

Question 69

The Precambrian comprises what percent of geologic time?

A) 99%
B) 88%
C) 77%
D) 66%
E) 55%

Question 70

The rapid rate of plate motion was probably the most important factor in rapid continental growth in the Late Archean.

Question 71

The giant batholiths of the Sierra, Idaho, and Coast Range were emplaced during the:

A) Sevier orogeny.
B) Nevadan orogeny.
C) Sonoma orogeny.
D) Laramide orogeny.
E) Allegheny orogeny.

Question 72

A cratonic sequence is recognized by a:

A) transgressive phase followed by regressive phase.
B) regressive phase followed by a transgressive phase.
C) regressive phase only.
D) transgressive phase only.
E) lack of any sequence.

Question 73

Areas of elongated mountain-building activity are called:

A) shields.
B) mobile belts.
C) platforms.
D) immobile belts.
E) all of the above

Question 74

Pennsylvanian rocks have a characteristic cyclical deposition sequence of ____ and ____ sediments called ____.

A) shale, carbonate, varves
B) marine, nonmarine, varves
C) carbonate, shale, cyclothems
D) marine, nonmarine, cyclothems
E) none of the above

Question 75

The Acadian orogeny occurred as a result of:

A) continental-continental collision followed by oceanic-continental collision.
B) oceanic-continental collision.
C) continental-continental collision.
D) oceanic-continental collision followed by continental-continental collision.
E) continental-continental collision followed by transform faulting.

Question 76

The orogenic event of the North American Cordillera, which began in the Late Cretaceous and extended into the Cenozoic, is the:

A) Laramide orogeny.
B) Sevier orogeny.
C) Nevadan orogeny.
D) Antler orogeny.
E) Appalachian orogeny.

Question 77

The Grenville orogeny was the culminating event of the amalgamation of Laurentia.

Question 78

The Queenston Delta formed in response to the:

A) erosion of the Taconic Highlands.
B) subduction of the Iapetus plate.
C) uplift of the Caledonides.
D) carbonate deposition.
E) Mississippi River.

Question 79

The rate of plate motion was probably slower in the Archean.

Question 80

Weathering and erosion of the Acadian Highlands produced a clastic wedge known as the:

A) Queenston Delta.
B) Acadian Delta.
C) Catskill Delta.
D) Appalachian Delta.
E) Mississippi Delta.