Question 1

In a disconformity:

Accepted Answer

A)  the sedimentary layers above and below the unconformity are parallel. 
B)  the sedimentary layers below the unconformity are tilted. 
C)  sedimentary rocks lie on older metamorphic rocks. 
D)  sedimentary rocks lie on older igneous rocks. 
A)  the sedimentary layers above and below the unconformity are parallel. 
B)  the sedimentary layers below the unconformity are tilted. 
C)  sedimentary rocks lie on older metamorphic rocks. 
D)  sedimentary rocks lie on older igneous rocks.

Question 2

The smallest unit of geologic time is a/an __________.

Accepted Answer

A)  era 
B)  epoch 
C)  eon 
D)  period 
A)  era 
B)  epoch 
C)  eon 
D)  period

Question 3

Relative age measurement provides scientists with age measured in years.

Accepted Answer

A) True 
 B)False

Question 4

The half-life of potassium-40 is 1.3 billion years. If a rock that formed 2.6 billion years ago originally contained 5 grams of potassium-40, about __________ grams of potassium-40 would be left in that rock today.

Accepted Answer

A)  0.0125 
B)  0.125 
C)  1.25 
D)  0.25 
A)  0.0125 
B)  0.125 
C)  1.25 
D)  0.25

Question 5

Parent and daughter isotopes occur when an isotope is __________.

Accepted Answer

A)  stable 
B)  unstable 
C)  radioactive 
D)  b and c 
A)  stable 
B)  unstable 
C)  radioactive 
D)  b and c

Question 6

Scientists have determined the Earth's age to be about __________ years.

Accepted Answer

A)  65 million 
B)  248 million 
C)  543 million 
D)  4.6 billion 
A)  65 million 
B)  248 million 
C)  543 million 
D)  4.6 billion

Question 7

In a __________, the sedimentary layers above and below the unconformity are parallel.

Accepted Answer

A)  nonconformity 
B)  disconformity 
C)  angular unconformity 
D)  correlative unconformity 
A)  nonconformity 
B)  disconformity 
C)  angular unconformity 
D)  correlative unconformity

Question 8

Isotopes with long half-lives give good ages for old rocks, but not enough daughter isotopes accumulate in young rocks for good age measurement.

Accepted Answer

A) True 
 B)False

Question 9

Carbon-14 dating is used to determine the age of materials older than 50,000 years.

Accepted Answer

A) True 
 B)False

Question 10

__________ are atoms of the same element that have the same number of protons but different numbers of neutrons.

Accepted Answer

The answer of __________ are atoms of the same element...

Question 11

Geologic evidence for the cause of the extinction event at the end of the Cretaceous includes:

Accepted Answer

A)  a silicate-rich layer. 
B)  glacier deposits. 
C)  iron-nickel deposits. 
D)  an iridium-rich layer. 
A)  a silicate-rich layer. 
B)  glacier deposits. 
C)  iron-nickel deposits. 
D)  an iridium-rich layer.

Question 12

A magmatic intrusion cutting through sedimentary layers:

Accepted Answer

A)  must be younger than these sedimentary layers. 
B)  must be older than these sedimentary layers. 
C)  is of exactly the same age as these sedimentary layers. 
D)  cannot be used for any relative age measurements. 
A)  must be younger than these sedimentary layers. 
B)  must be older than these sedimentary layers. 
C)  is of exactly the same age as these sedimentary layers. 
D)  cannot be used for any relative age measurements.

Question 13

Volcanic eruptions can influence the climate both by cooling as well as by warming the atmosphere.

Accepted Answer

A) True 
 B)False

Question 14

Geologists use radioactive elements in rocks mainly to identify:

Accepted Answer

A)  their relative age. 
B)  an angular disconformity. 
C)  a nonconformity. 
D)  their absolute age. 
A)  their relative age. 
B)  an angular disconformity. 
C)  a nonconformity. 
D)  their absolute age.

Question 15

The principle of __________ states that most sediment is deposited as nearly horizontal beds.

Accepted Answer

A)  superposition 
B)  original horizontality 
C)  limited horizontality 
D)  faunal succession 
A)  superposition 
B)  original horizontality 
C)  limited horizontality 
D)  faunal succession

Question 16

Fish, amphibians, and reptiles all evolved during the __________ Era/Eon.

Accepted Answer

A)  Cenozoic 
B)  Mesozoic 
C)  Paleozoic 
D)  Proterozoic 
A)  Cenozoic 
B)  Mesozoic 
C)  Paleozoic 
D)  Proterozoic

Question 17

During a __________ __________, many life-forms on Earth die out suddenly.

Accepted Answer

The answer of During a __________ __________, many life-forms on...

Question 18

A basalt dike cutting older sedimentary rocks is an example of the principle of __________ __________.

Accepted Answer

crosscutti

Question 19

The biggest mass extinction in Earth's history occurred at the end of the __________ Period.

Accepted Answer

A)  Ordovician 
B)  Permian 
C)  Cretaceous 
D)  Tertiary 
A)  Ordovician 
B)  Permian 
C)  Cretaceous 
D)  Tertiary

Question 20

Layers of sedimentary rock are __________ if they were deposited without detectable interruption.

Accepted Answer

A)  conformable 
B)  disconformable 
C)  unconformable 
D)  nonconformable 
A)  conformable 
B)  disconformable 
C)  unconformable 
D)  nonconformable

Exam 4: Geologic Time: a Story in the Rocks

In a disconformity:

The smallest unit of geologic time is a/an __________.

Relative age measurement provides scientists with age measured in years.

The half-life of potassium-40 is 1.3 billion years. If a rock that formed 2.6 billion years ago originally contained 5 grams of potassium-40, about __________ grams of potassium-40 would be left in that rock today.

Parent and daughter isotopes occur when an isotope is __________.

Scientists have determined the Earth's age to be about __________ years.

In a __________, the sedimentary layers above and below the unconformity are parallel.

Isotopes with long half-lives give good ages for old rocks, but not enough daughter isotopes accumulate in young rocks for good age measurement.

Carbon-14 dating is used to determine the age of materials older than 50,000 years.

__________ are atoms of the same element that have the same number of protons but different numbers of neutrons.

Geologic evidence for the cause of the extinction event at the end of the Cretaceous includes:

A magmatic intrusion cutting through sedimentary layers:

Volcanic eruptions can influence the climate both by cooling as well as by warming the atmosphere.

Geologists use radioactive elements in rocks mainly to identify:

The principle of __________ states that most sediment is deposited as nearly horizontal beds.

Fish, amphibians, and reptiles all evolved during the __________ Era/Eon.

During a __________ __________, many life-forms on Earth die out suddenly.

A basalt dike cutting older sedimentary rocks is an example of the principle of __________ __________.

The biggest mass extinction in Earth's history occurred at the end of the __________ Period.

Layers of sedimentary rock are __________ if they were deposited without detectable interruption.

Earth Systems

Minerals

Rocks

Geologic Resources

The Active Earth: Plate Tectonics

Earthquakes and the Earths Structure

Volcanoes and Plutons

Mountains

Weathering, Soil, and Erosion

Fresh Water: Streams, Lakes, Ground Water, and Wetlands

Water Resources

Glaciers and Ice Ages

Deserts and Wind

Ocean Basins

Oceans and Coastlines

The Atmosphere

Energy Balance in the Atmosphere

Moisture, Clouds, and Weather

Climate

Climate Change

Motions in the Heavens

Planets and Their Moons

Stars, Space, and Galaxies

Filters

During a , many life-forms on Earth die out suddenly.

A basalt dike cutting older sedimentary rocks is an example of the principle of .