Solution Manual
To Accompany Essentials Of
Geology,Marshak,
5th Edition
, CHAPTER 1
The Earth In Context
Learning Objectives
1. Students Should Be Aware Of The Big Bang Theory. Distant Galaxies Are All
Moving Away From Us. The Farthest Galaxies Are Receding From Us The Fastest.
All Matter In TheUniverse Was Contained In A Single Point, Approximately 13.8
Billion Years Ago. At That Time, The Universe Explosively Came Into Existence.
2. Stars, Including Our Sun, Are Nuclear-Fusion Reactors. For Most Of Their Life
Histories (On The Order Of Billions Of Years), Hydrogen Atoms Are Fused
Together To Form Helium.Later Stages In Stellar Evolution Include Fusion Of
Helium Atoms And Other, Heavier Elements; Ultimately, Iron Is The Heaviest
Element That Can Be Produced Through FusionReactions Within Stars.
3. After Their Cycles Of Fusion Are Complete, Large Stars Violently Explode
(Forming Supernovas), Producing Elements Heavier Than Iron And Leaving
Behind A Residue OfDiffuse Nebulae, Which May Be Recycled To Form A New
Star At Some Future Point.
4. Our Solar System Is Approximately 4.57 Ga (Billion Years Old). All Eight Planets
Revolve Around The Sun In Coplanar, Elliptical Orbits. All Planets Orbit In The
Same Direction (Counterclockwise, As Viewed From Above Earth’s North Pole).
These Facts Imply Simultaneous Planetary Formation From A Swirling Nebula
, Surrounding The Sun (The Similarities In Orbits Would Then Be A Natural Result
Of Conservation Of Angular Momentum). The Planets Accreted From This Nebula
Through Gravitational Attraction And Haphazard Collisions. Pluto, Long Considered
The “Ninth Planet,” Has Seen Its StatusDemoted; Astronomers Now Recognize
Eight Major Planets.
5. The Terrestrial Planets (Mercury, Venus, Earth, And Mars) Are Relatively Small,
Dense,And Rocky Worlds. The Giant Planets Are Predominantly Composed Of The
Light Gases Hydrogen And Helium (Jupiter And Saturn) Or Ices (Uranus And
Neptune); They Are
, Much Larger And Much Less Dense Than The Terrestrial Planets.
6. Our Moon Is Thought To Have Originated From Debris Accumulated When A
ProtoplanetCollided With Earth Approximately 4.53 Ga.
7. The Earth System Is Subdivided Into The Atmosphere (Gases And Aerosols That
EnvelopThe Planet), Hydrosphere (Earth’s Water), Geosphere (Solid Earth), And
Biosphere (Living Things).
8. Earth Is Chemically Divided Into A Thin, Rocky Crust Dominated By Silicate
Minerals, A Thick Mantle Composed Mostly Of Iron- And Magnesium-Rich
Silicates (Subject Locally To Partial Melting), And A Thick, Metallic Core Made
Primarily Of Iron (The Outer PortionOf Which Is Liquid). Students Should Know
How Seismic Waves Tell Us That The Outer Core Must Be Liquid.
9. Physically, The Uppermost Layers Of Earth Are The Rigid Lithosphere (Crust And
Uppermost Mantle) And The Asthenosphere, Which Is Weaker And Flows
Plastically. The“Plates” Of Plate Tectonics Theory Are Discrete Slabs Of
Lithosphere, Which Move With Respect To One Another Atop The Asthenosphere.
Summary From The Text
The Geocentric Model Placed Earth At The Center Of The Universe. The
HeliocentricModel Placed The Sun At The Center.
The Earth Is One Of Eight Planets Orbiting The Sun. The Solar System Lies On The
OuterEdge Of The Milky Way Galaxy. The Universe Contains Hundreds Of Billions Of
Galaxies.
Most Astronomers Agree That This Expansion Began After The Big Bang, A
CataclysmicExplosion That Occurred About 13.7 Billion Years Ago.
The First Atoms (Hydrogen And Helium) Of The Universe Developed Within
Minutes OfThe Big Bang. These Atoms Formed Vast Gas Clouds, Called Nebulae.
Only Very Small Atoms Formed During Big Bang Nucleosynthesis. The Earth, And
The Life Forms On It, Contain Elements That Could Have Been Produced Only During
The Life Cycle
To Accompany Essentials Of
Geology,Marshak,
5th Edition
, CHAPTER 1
The Earth In Context
Learning Objectives
1. Students Should Be Aware Of The Big Bang Theory. Distant Galaxies Are All
Moving Away From Us. The Farthest Galaxies Are Receding From Us The Fastest.
All Matter In TheUniverse Was Contained In A Single Point, Approximately 13.8
Billion Years Ago. At That Time, The Universe Explosively Came Into Existence.
2. Stars, Including Our Sun, Are Nuclear-Fusion Reactors. For Most Of Their Life
Histories (On The Order Of Billions Of Years), Hydrogen Atoms Are Fused
Together To Form Helium.Later Stages In Stellar Evolution Include Fusion Of
Helium Atoms And Other, Heavier Elements; Ultimately, Iron Is The Heaviest
Element That Can Be Produced Through FusionReactions Within Stars.
3. After Their Cycles Of Fusion Are Complete, Large Stars Violently Explode
(Forming Supernovas), Producing Elements Heavier Than Iron And Leaving
Behind A Residue OfDiffuse Nebulae, Which May Be Recycled To Form A New
Star At Some Future Point.
4. Our Solar System Is Approximately 4.57 Ga (Billion Years Old). All Eight Planets
Revolve Around The Sun In Coplanar, Elliptical Orbits. All Planets Orbit In The
Same Direction (Counterclockwise, As Viewed From Above Earth’s North Pole).
These Facts Imply Simultaneous Planetary Formation From A Swirling Nebula
, Surrounding The Sun (The Similarities In Orbits Would Then Be A Natural Result
Of Conservation Of Angular Momentum). The Planets Accreted From This Nebula
Through Gravitational Attraction And Haphazard Collisions. Pluto, Long Considered
The “Ninth Planet,” Has Seen Its StatusDemoted; Astronomers Now Recognize
Eight Major Planets.
5. The Terrestrial Planets (Mercury, Venus, Earth, And Mars) Are Relatively Small,
Dense,And Rocky Worlds. The Giant Planets Are Predominantly Composed Of The
Light Gases Hydrogen And Helium (Jupiter And Saturn) Or Ices (Uranus And
Neptune); They Are
, Much Larger And Much Less Dense Than The Terrestrial Planets.
6. Our Moon Is Thought To Have Originated From Debris Accumulated When A
ProtoplanetCollided With Earth Approximately 4.53 Ga.
7. The Earth System Is Subdivided Into The Atmosphere (Gases And Aerosols That
EnvelopThe Planet), Hydrosphere (Earth’s Water), Geosphere (Solid Earth), And
Biosphere (Living Things).
8. Earth Is Chemically Divided Into A Thin, Rocky Crust Dominated By Silicate
Minerals, A Thick Mantle Composed Mostly Of Iron- And Magnesium-Rich
Silicates (Subject Locally To Partial Melting), And A Thick, Metallic Core Made
Primarily Of Iron (The Outer PortionOf Which Is Liquid). Students Should Know
How Seismic Waves Tell Us That The Outer Core Must Be Liquid.
9. Physically, The Uppermost Layers Of Earth Are The Rigid Lithosphere (Crust And
Uppermost Mantle) And The Asthenosphere, Which Is Weaker And Flows
Plastically. The“Plates” Of Plate Tectonics Theory Are Discrete Slabs Of
Lithosphere, Which Move With Respect To One Another Atop The Asthenosphere.
Summary From The Text
The Geocentric Model Placed Earth At The Center Of The Universe. The
HeliocentricModel Placed The Sun At The Center.
The Earth Is One Of Eight Planets Orbiting The Sun. The Solar System Lies On The
OuterEdge Of The Milky Way Galaxy. The Universe Contains Hundreds Of Billions Of
Galaxies.
Most Astronomers Agree That This Expansion Began After The Big Bang, A
CataclysmicExplosion That Occurred About 13.7 Billion Years Ago.
The First Atoms (Hydrogen And Helium) Of The Universe Developed Within
Minutes OfThe Big Bang. These Atoms Formed Vast Gas Clouds, Called Nebulae.
Only Very Small Atoms Formed During Big Bang Nucleosynthesis. The Earth, And
The Life Forms On It, Contain Elements That Could Have Been Produced Only During
The Life Cycle
