Question 1

Which statement best summarizes the development of the geologic time scale?

Accepted Answer

A) Numerical ages for rocks were known before the relative sequence of sedimentary layers was established. 
B) Relative ages for sedimentary strata were known before accurate numerical dates for these rocks were measured. 
C) Names of relative ages (such as Silurian)and accurate numerical dates for these ages became known at about the same time. 
D) Numerical ages for fossils were known before the relative sequence of sedimentary layers was established. 
A) Numerical ages for rocks were known before the relative sequence of sedimentary layers was established. 
B) Relative ages for sedimentary strata were known before accurate numerical dates for these rocks were measured. 
C) Names of relative ages (such as Silurian)and accurate numerical dates for these ages became known at about the same time. 
D) Numerical ages for fossils were known before the relative sequence of sedimentary layers was established.

Question 2

Which statement about contact #3 is correct?

Accepted Answer

A) It and contact #2 once formed a continuous unconformity. 
B) It was once elevated farther above contact #2,but faulting has brought them closer together. 
C) It presents an example of an angular unconformity. 
D) It must be younger than the conglomerate,due to the principle of baked contacts. 
A) It and contact #2 once formed a continuous unconformity. 
B) It was once elevated farther above contact #2,but faulting has brought them closer together. 
C) It presents an example of an angular unconformity. 
D) It must be younger than the conglomerate,due to the principle of baked contacts.

Question 3

In an unweathered sample of rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

Accepted Answer

A) 200 million years 
B) 400 million years 
C) 750 million years 
D) 1 billion years 
A) 200 million years 
B) 400 million years 
C) 750 million years 
D) 1 billion years

Question 4

As understood by modern geologists,the principle of uniformitarianism implies that ________.

Accepted Answer

A) the Earth has always had the same basic appearance that it has today 
B) igneous,metamorphic,and sedimentary rocks are uniformly mixed throughout the crust 
C) physical processes observed today (such as erosion and volcanic eruption)have been active in the past and are preserved in the rock record 
D) physical processes observed today (such as erosion and volcanic eruption)have been occurring throughout Earth history at constant rates 
A) the Earth has always had the same basic appearance that it has today 
B) igneous,metamorphic,and sedimentary rocks are uniformly mixed throughout the crust 
C) physical processes observed today (such as erosion and volcanic eruption)have been active in the past and are preserved in the rock record 
D) physical processes observed today (such as erosion and volcanic eruption)have been occurring throughout Earth history at constant rates

Question 5

In an unweathered sample of igneous rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

Accepted Answer

A) 200 million years 
B) 400 million years 
C) 750 million years 
D) 1 billion years 
A) 200 million years 
B) 400 million years 
C) 750 million years 
D) 1 billion years

Question 6

Uniformitarianism is succinctly summarized by which phrase?

Accepted Answer

A) The future is the key to the present. 
B) The present is the key to the past. 
C) The past is the key to the present. 
D) The present is the key to the future. 
A) The future is the key to the present. 
B) The present is the key to the past. 
C) The past is the key to the present. 
D) The present is the key to the future.

Question 7

Within the world's sedimentary rocks,fossils ________.

Accepted Answer

A) are rarely,if ever,found 
B) are randomly distributed 
C) occur in an ordered sequence 
D) are found only in igneous rocks 
A) are rarely,if ever,found 
B) are randomly distributed 
C) occur in an ordered sequence 
D) are found only in igneous rocks

Question 8

Two atoms of a single element that differ in number of neutrons are said to represent two distinct ________ of that element.

Accepted Answer

A) isomers 
B) isotopes 
C) isotherms 
D) atomic species 
A) isomers 
B) isotopes 
C) isotherms 
D) atomic species

Question 9

The closure temperature represents the point when ________.

Accepted Answer

A) a magma cools to the point where minerals begin to crystallize 
B) radioactive isotopes begin to decay 
C) isotopes are no longer free to move out of a crystal lattice 
D) the last remaining magma crystallizes 
A) a magma cools to the point where minerals begin to crystallize 
B) radioactive isotopes begin to decay 
C) isotopes are no longer free to move out of a crystal lattice 
D) the last remaining magma crystallizes

Question 10

Contact #3 is both a ________ and a(n)________ at various points.

Accepted Answer

A) conformable contact;unconformity 
B) fault;unconformity 
C) nonconformity;angular unconformity 
D) disconformity;nonconformity 
A) conformable contact;unconformity 
B) fault;unconformity 
C) nonconformity;angular unconformity 
D) disconformity;nonconformity

Question 11

Seasonal changes create layering in glaciers known as ________.

Accepted Answer

A) growth banding 
B) rhythmic layering 
C) seasonal layering 
D) annual banding 
A) growth banding 
B) rhythmic layering 
C) seasonal layering 
D) annual banding

Which statement best summarizes the development of the geologic time scale?

Which statement about contact #3 is correct?

In an unweathered sample of rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

As understood by modern geologists,the principle of uniformitarianism implies that ________.

In an unweathered sample of igneous rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

Uniformitarianism is succinctly summarized by which phrase?

Within the world's sedimentary rocks,fossils ________.

Two atoms of a single element that differ in number of neutrons are said to represent two distinct ________ of that element.

The closure temperature represents the point when ________.

Contact #3 is both a and a(n) at various points.

Seasonal changes create layering in glaciers known as ________.

Cosmology and the Birth of Earth

Journey to the Center of the Earth

Drifting Continents and Spreading Seas

The Way the Earth Works: Plate Tectonics

Patterns in Nature: Minerals

Up From the Inferno: Magma and Igneous Rocks

Pages of Earths Past: Sedimentary Rocks

Metamorphism: a Process of Change

The Wrath of Vulcan: Volcanic Eruptions

A Violent Pulse: Earthquakes

Crags,cracks,and Crumples: Crustal Deformation and Mountain Building

A Biography of Earth

Squeezing Power From a Stone: Energy Resources

Riches in Rock: Mineral Resources

Unsafe Ground: Landslides and Other Mass Movements

Streams and Floods: the Geology of Running Water

Restless Realm: Oceans and Coasts

A Hidden Reserve: Groundwater

An Envelope of Gas: Earths Atmosphere and Climate

Dry Regions: the Geology of Deserts

Amazing Ice: Glaciers and Ice Ages

Global Change in the Earth System

Introducing Rocks

a Surface Veneer: Sediments and Soils

the Rock Cycle in the Earth System

the Earths Interior, revisited: Seismic Layering, gravity, and the Magnetic Field

Memories of Past Life: Fossils and Evolution

Ever-Changing Landscapes and the Hydrologic Cycle

Filters

Exam 12: Deep Time: How Old Is Old

Which statement best summarizes the development of the geologic time scale?

Which statement about contact #3 is correct?

In an unweathered sample of rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

As understood by modern geologists,the principle of uniformitarianism implies that ________.

In an unweathered sample of igneous rock,the ratio of an unstable isotope to its stable daughter isotope is 1:15.If no daughters were present at the time the rock cooled below closure temperature,and the half-life of the isotope is 50 million years,how old is the rock?

Uniformitarianism is succinctly summarized by which phrase?

Within the world's sedimentary rocks,fossils ________.

Two atoms of a single element that differ in number of neutrons are said to represent two distinct ________ of that element.

The closure temperature represents the point when ________.

Contact #3 is both a ________ and a(n)________ at various points.

Seasonal changes create layering in glaciers known as ________.

Cosmology and the Birth of Earth

Journey to the Center of the Earth

Drifting Continents and Spreading Seas

The Way the Earth Works: Plate Tectonics

Patterns in Nature: Minerals

Up From the Inferno: Magma and Igneous Rocks

Pages of Earths Past: Sedimentary Rocks

Metamorphism: a Process of Change

The Wrath of Vulcan: Volcanic Eruptions

A Violent Pulse: Earthquakes

Crags,cracks,and Crumples: Crustal Deformation and Mountain Building

A Biography of Earth

Squeezing Power From a Stone: Energy Resources

Riches in Rock: Mineral Resources

Unsafe Ground: Landslides and Other Mass Movements

Streams and Floods: the Geology of Running Water

Restless Realm: Oceans and Coasts

A Hidden Reserve: Groundwater

An Envelope of Gas: Earths Atmosphere and Climate

Dry Regions: the Geology of Deserts

Amazing Ice: Glaciers and Ice Ages

Global Change in the Earth System

Introducing Rocks

a Surface Veneer: Sediments and Soils

the Rock Cycle in the Earth System

the Earths Interior, revisited: Seismic Layering, gravity, and the Magnetic Field

Memories of Past Life: Fossils and Evolution

Ever-Changing Landscapes and the Hydrologic Cycle

Filters

Contact #3 is both a and a(n) at various points.