Question 1

During the Cretaceous period,Earth experienced a worldwide rise in sea level caused by
A)melting of glacial ice.
B)the thermal expansion of the crustal surface and the breakup of Pangaea.
C)subduction of the seafloor.
D)subduction of continental land masses.

Accepted Answer

The thermal expansion of the crustal surface and the breakup of Pangaea caused the worldwide rise in sea level during the Cretaceous period. Melting of glacial ice and subduction of the seafloor or continental land masses were not significant factors in causing this rise in sea level.

Question 2

The high concentration of iridium at the Cretaceous Tertiary boundary is most likely attributed to
A)a worldwide rise in sea level.
B)meteorite bombardment.
C)an out flux of iridium from Earth's interior.
D)none of the above

Accepted Answer

The high concentration of iridium at the Cretaceous Tertiary boundary is believed to be attributed to a meteorite impact. Iridium is a rare element on Earth's crust, but it is more common in meteorites. Therefore, the sudden influx of iridium at the boundary suggests a large meteorite impact, which is also supported by the existence of the Chicxulub Crater in Mexico. The other options are not supported by scientific evidence.

Question 3

Coal beds are formed from the accumulation of plant material that becomes trapped in swamp floors.Yet coal deposits are present in the continent of Antarctica,where no swamps or vegetation exists.How can this be?

Accepted Answer

The answer of Coal beds are formed from the accumulation...

Question 4

Why does sea level rise when spreading rate increases?

Accepted Answer

The answer of Why does sea level rise when spreading...

Question 5

What types of events ended the Paleozoic era?

Accepted Answer

The answer of What types of events ended the Paleozoic...

Question 6

Ancient coal beds can be found in Antarctica because
A)at one time the climate of Antarctica was mild enough to support swamplands.
B)ancient coal beds were frozen in the Antarctic ice.
C)it used to be located in the northern hemisphere.
D)it was located at the equator during the Carboniferous period.

Accepted Answer

Ancient coal beds can be found in Antarctica because at one time the climate of Antarctica was mild enough to support swamplands. During the Carboniferous period (about 360-300 million years ago), Antarctica was located closer to the equator and had a warmer climate. Plants thrived in the swampy environment, and over time, the organic material from the plants formed coal beds. As Antarctica moved to its current position in the Southern Hemisphere, the coal beds were buried under ice and preserved.

Question 7

What spectacular development in organisms marks the beginning of the Paleozoic era?

Accepted Answer

The answer of What spectacular development in organisms marks the...

Question 8

Possible ways that sea level could lower include a decrease in
A)worldwide temperatures and an increase in the rate of seafloor spreading.
B)worldwide temperatures and a decrease in the rate of seafloor spreading.
C)tectonic activity and an increase in worldwide temperatures.
D)the rate of seafloor spreading and an increase in worldwide temperatures.

Accepted Answer

The melting of polar ice caps due to rising temperatures is a major contributor to the increase in sea level. Therefore, a decrease in worldwide temperatures would lead to a decrease in sea level. Additionally, the rate of seafloor spreading directly affects the volume of the ocean floor and can impact sea level. A decrease in the rate of seafloor spreading would decrease the volume of the ocean floor and thus lower sea level. Tectonic activity and an increase in worldwide temperatures would have the opposite effect and increase sea level. Therefore, options A and D can be eliminated.

Question 9

The emergence of terrestrial life-for example,land plants,came about during the
A)Triassic.
B)Silurian.
C)Ordovician.
D)Carboniferous era.

Accepted Answer

Land plants first appeared during the Silurian period, which significantly contributed to the development of terrestrial ecosystems.

Question 10

All continental landmasses joined together as Pangaea resulted in
A)a reduction in shallow marine habitats.
B)a long duration of high sea level.
C)an increase of seafloor spreading.
D)increased species diversification.

Accepted Answer

When all continental landmasses joined together to form Pangaea, the amount of shallow marine habitats greatly reduced, since large inland bodies of water would have disappeared. This led to the extinction of many marine species in these regions.

Question 11

Why is it believed that large parts of the United States were once covered by shallow seas?

Accepted Answer

The answer of Why is it believed that large parts...

Question 12

The Mesozoic era is known as the age of the
A)dinosaur.
B)reptile.
C)fishes.
D)synapsids.

Accepted Answer

The answer of The Mesozoic era is known as the...

Question 13

The supercontinent of Pangaea formed during the
A)Cenozoic.
B)Paleozoic.
C)Mesozoic.
D)Precambrian.

Accepted Answer

The formation of Pangaea occurred during the Paleozoic era, specifically in the late Paleozoic (about 300 million years ago). This was a time when most of Earth's landmasses were combined into one large supercontinent.

Question 14

The "Cambrian explosion" refers to the
A)great many meteorite bombardments that occurred during that time.
B)great diversity of life that blossomed during that time.
C)evolution and great diversity of blastoids during that time period.
D)numerous volcanic eruptions that took place during that time.

Accepted Answer

The "Cambrian explosion" refers to the great diversity of life that blossomed during that time. It was a period of rapid evolution and diversification of many new species, occurring over approximately 20-25 million years during the early Cambrian period (around 541-510 million years ago).

Question 15

Organisms with the ability to be easily preserved as fossils began to flourish about
A)4.6 billion years ago.
B)3.8 billion years ago.
C)543 million years ago.
D)65 million years ago.

Accepted Answer

The Cambrian explosion, which began 543 million years ago, saw a rapid diversification of organisms with the ability to be easily preserved as fossils. These included marine invertebrates such as trilobites, brachiopods, and mollusks. Prior to this, very few organisms had hard parts that could be preserved as fossils. Therefore, choice C is the best option.

Question 16

The first time period for which abundant fossils have been found is the
A)Precambrian.
B)Silurian.
C)Pliocene.
D)Cambrian.

Accepted Answer

Abundant fossil evidence has been found from the Cambrian period, which lasted from approximately 541 million years ago to 485 million years ago. This period is known for the sudden appearance of complex organisms with hard shells, such as trilobites and brachiopods. Prior to the Cambrian period, there is some fossil evidence, but it is sparse and primarily consists of single-celled organisms.

Question 17

Paleozoic sedimentary rocks derived from marine deposits are widely distributed in all of the continents.What does this indicate about the height of the continents relative to sea level during the Paleozoic?

Accepted Answer

The answer of Paleozoic sedimentary rocks derived from marine deposits...

Question 18

Earth's early life forms were marine organisms.Life moved to the land during the
A)Cambrian period.
B)Ordovician period.
C)Silurian period.
D)Triassic period.

Accepted Answer

The Silurian period is when the first terrestrial (land-dwelling) animals evolved, including plants, arthropods (such as spiders and scorpions), and early vertebrates like fish that had developed adaptations to breathe air. However, the first marine organisms to colonize land were likely fungi and plants that appeared even earlier, during the Ordovician period.

Question 19

At the end of the Ordovician,many shallow-marine organisms went extinct due to
A)deep water predators.
B)a long duration of high sea level.
C)cooling temperatures,increased glaciation,and decreased sea level.
D)cooling temperatures,increased glaciation,and a rise in sea level.

Accepted Answer

The cooling temperatures and increased glaciation during the end of the Ordovician led to a decrease in sea level, which negatively impacted shallow-marine organisms. Deep water predators (A) and a long duration of high sea level (B) were not significant factors in the extinction of these organisms. Option D includes a rise in sea level, which is contradictory to the actual scenario.

Question 20

The Permian extinction predominantly affected
A)reptiles.
B)marine life.
C)insects life.
D)terrestrial life.

Accepted Answer

The Permian extinction, also known as the Great Dying, was the most severe extinction event in Earth's history, and it predominantly affected marine life. It is estimated that up to 96% of all marine species died out during this time. While some terrestrial and freshwater species were also affected, the impact on marine life was much greater.

Quiz 23: Geologic Time - Reading the Rock Record

During the Cretaceous period,Earth experienced a worldwide rise in sea level caused by

The high concentration of iridium at the Cretaceous Tertiary boundary is most likely attributed to

Coal beds are formed from the accumulation of plant material that becomes trapped in swamp floors.Yet coal deposits are present in the continent of Antarctica,where no swamps or vegetation exists.How can this be?

Why does sea level rise when spreading rate increases?

What types of events ended the Paleozoic era?

Ancient coal beds can be found in Antarctica because

What spectacular development in organisms marks the beginning of the Paleozoic era?

Possible ways that sea level could lower include a decrease in

The emergence of terrestrial life-for example,land plants,came about during the

All continental landmasses joined together as Pangaea resulted in

Why is it believed that large parts of the United States were once covered by shallow seas?

The Mesozoic era is known as the age of the

The supercontinent of Pangaea formed during the

The "Cambrian explosion" refers to the

Organisms with the ability to be easily preserved as fossils began to flourish about

The first time period for which abundant fossils have been found is the

Paleozoic sedimentary rocks derived from marine deposits are widely distributed in all of the continents.What does this indicate about the height of the continents relative to sea level during the Paleozoic?

Earth's early life forms were marine organisms.Life moved to the land during the

At the end of the Ordovician,many shallow-marine organisms went extinct due to

The Permian extinction predominantly affected