Deck 17: Earth History

Question 1

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

Answer 1

The orogeny took place much further inland from a convergent boundary,and volcanism and plutonism were not very common.Also,mountain building was mostly vertical,fault-bounded uplift rather than compression-induced folding and thrust faulting.

Question 2

Briefly describe the geologic history of the North American Cordillera.

Answer 2

The history of the Cordillera is long and complex,involving accretion of island arcs along the continental margin,orogeny at an oceanic-continental boundary,vast outpourings of basaltic lava,and block faulting.After cessation of the Laramide orogeny,mountain ranges eroded.During the Early Cenozoic,a subduction zone stretched off the Pacific Coast from Mexico to Alaska where the Farallon plate was consumed.All that remains are the Juan de Fuca and Cocos plates.

Question 3

What was the tectonic evolution of western North America beginning with the Permian and through the Mesozoic?

Answer 3

During the Permian,an island arc and ocean basin formed off western North America,and then an oceanic plate subducted beneath the island arc.Oceanic and island arc rocks were thrust eastward against the craton during the Permian-Triassic boundary.In the Early Mesozoic,western North America became an oceanic-continental convergent plate boundary,with a steeply dipping subduction zone as North America moved over the Pacific plate.

Question 4

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

Question 5

What is the origin of greenstone belts?

Question 6

Describe the beginning of operations of Earth's systems and when that occurred.

Question 7

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

Question 8

Describe the history of the Pleistocene ice ages.

Question 9

Describe the coming together of Pangaea.What was the name of what the rest of the planet covered with besides this supercontinent?

Question 10

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

Question 11

Describe the four stages of the breakup of Pangaea.

Question 12

Describe the geologic history of the Ancestral Rockies.

Question 13

What tectonic event caused the Taconic and Acadian orogenies?

Question 14

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 15

Outline the history of the Alpine-Himalayan belt.

Question 16

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

Question 17

How does the Absaroka sequence differ from the Kaskaskia sequence? What do these differences mean for the environment of the time?

Question 18

How did the landmass called Laurentia come together?

Question 19

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

Question 20

What do cyclothems represent?

Question 21

What was the Sundance Sea?

Question 22

What are mobile belts of a continent?

Question 23

When and where did the Acadian orogeny occur?

Question 24

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

Question 25

Describe the first phase of the Cordilleran orogeny.

Question 26

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

Question 27

What is the Tippecanoe sequence?

Question 28

Name the two periods into which the Cenozoic is divided.

Question 29

What is the North American Cordillera?

Question 30

What worldwide effect was caused by Gondwana moving over the south pole during the Carboniferous Period?

Question 31

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

Question 32

How and when did Florida form?

Question 33

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

Question 34

What role did microplates play in the formation of Pangaea?

Question 35

What caused the Alpine orogeny?

Question 36

When and where did the Antler orogeny occur?

Question 37

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

Question 38

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

Question 39

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

Question 40

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

Question 41

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

Question 42

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 43

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

Question 44

The three phases of the Cordilleran orogeny,in order from oldest to youngest,were the ____________________,____________________,and ____________________.

Question 45

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

Question 46

During the Pleistocene of North America,there were at least ____________________ glacial stages.These stages,in order from oldest to youngest,are the ____________________,____________________,____________________,and ____________________.

Question 47

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

Question 48

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

Question 49

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

Question 50

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

Question 51

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

Question 52

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

Question 53

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 54

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

Question 55

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

Question 56

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

Question 57

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

Question 58

Pangaea was formed from tectonic plates and ____________________.

Question 59

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

Question 60

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

Question 61

Archean and Proterozoic greenstone belts formed in similar tectonic settings.

Question 62

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.

Question 63

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 64

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

Question 65

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

Question 66

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 67

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 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

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 70

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

Question 71

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 72

The Precambrian comprises what percent of geologic time?

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

Question 73

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 74

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 75

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 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 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 78

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 79

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

Question 80

Areas of elongated mountain-building activity are called:

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