xix
Distinguishing Features
Readability
The language of this book is straightforward and written to be understood. Clear, readable discussions with a minimum of technical language are the rule. The frequent headings and subheadings help
students follow discussions and identify the important ideas presented in each chapter. In the Eleventh Edition, we have improved
readability by examining the chapter organization and flow and by
writing in a more personal style. Significant portions of several
chapters were substantially rewritten in an effort to make the material more understandable.
Maintaining a Focus on Basic Principles
and Instructor Flexibility
The main focus of the Eleventh Edition remains the same as in the
first ten: to foster student understanding of basic geological principles. As much as possible, we have attempted to provide the reader
with a sense of the observational techniques and reasoning
processes that constitute the discipline of geology.
The organization of the text remains intentionally traditional.
Following the overview of geology in Chapter 1, we turn to a
discussion of Earth materials and the related processes of volcanism
and weathering. Next, we explore the geological work of gravity, water,
wind, and ice in modifying and sculpting landscapes. After this look at
external processes, we examine Earth’ s internal structure and the
processes that deform rocks and give rise to mountains. The text
concludes with chapters on geologic time, Earth history, and global
climate change. This organization accommodates the study of minerals
and rocks in the laboratory, which usually comes early in the course.
Realizing that some instructors may prefer to organize their
courses somewhat differently, we made each of the chapters selfcontained so that they may be taught in a different sequence. Thus,
the instructor who wishes to discuss earthquakes, plate tectonics,
crustal deformation, and mountain building prior to dealing with
erosional processes may do so without difficulty. We also chose to
provide a brief introduction to plate tectonics in Chapter 1 so that
this important and basic theory could be incorporated in
appropriate places throughout the text.
A Strong Visual Component
Geology is highly visual, so art and photographs play a critical role
in an introductory textbook. As in the ten previous editions Dennis
Tasa, a gifted artist and respected geological illustrator, has worked
closely with the authors to plan and produce the diagrams, maps,
graphs, and sketches that are so basic to student understanding.
Dozens of the figures are new or redrawn. The result is art that is
clearer and easier to understand.
Our aim is to get the maximum effectiveness from the visual
component of the book. Michael Collier aided us greatly in this
quest. Dozens of his extraordinary aerial photographs are used in
the new edition. Michael is an award-winning geologistphotographer. Among his many awards is the American Geological
Institute Award for Outstanding Contribution to the Public
Understanding of the Geosciences. We are fortunate to have had
Michael’ s assistance in Essentials of Geology, Eleventh Edition.
New to the Eleventh Edition
• Significant updating and revision of content. With the goal of
keeping the text current and highly readable for beginning
students many discussions, case studies, and examples have
been revised. See the section on Revised and Updated Content
for many of the particulars.
• An all-new chapter on Global Climate Change. Chapter 20
looks at many links between geology and the climate system.
It examines how climate change is detected and, after an
overview of atmospheric “basics,” explores several important
natural causes of climate change. The chapter concludes with
an up-to-date examination of human impact on global
climate—a critical global environmental issue. The chapter
includes a rich array of graphs, diagrams, maps, and images.
• An even stronger art program. Dozens of figures are new or
redrawn. The result is art that is clearer and easier to understand. Numerous diagrams and maps are paired with photographs for greater effectiveness. Many new and revised art
pieces also have additional labels that “narrate” the process
being illustrated and/or “guide” readers as they examine the
figure.
• More than 150 new, high-quality photos and satellite images.
New “Geologist’ s Sketch” illustrations accompany many
important photographs and satellite images. Each sketch,
which resembles what a geologist might put in a field notebook, helps the student identify important and sometimes
subtle aspects of an image. This author–artist collaboration
helps make an already strong visual component even stronger
and more effective.
• An improved design. Anyone familiar with the previous edition will notice that we have continued the user-friendly
“look.” The design makes even more effective use of the wider
pages. The placement and integration of photographs and art
is less traditional and more creative. The scattering of Did You
Know? items through each chapter adds interest. The authors
and editors feel the improved design provides a more effective
and engaging visual impact.
Revised and Updated Content
The Eleventh Edition of Essentials of Geology represents a thorough
revision. Every part of the book was examined carefully with the
dual goals of keeping topics current and improving the clarity of
text discussions. Those familiar with the previous edition will see
much that is new. The list of specifics is long. Examples include the
following:
• Much of Chapter 2, “Matter and Minerals,” was rewritten in
an effort to make a sometimes difficult (chemistry-oriented)
Distinguishing Features
Readability
The language of this book is straightforward and written to be understood. Clear, readable discussions with a minimum of technical language are the rule. The frequent headings and subheadings help
students follow discussions and identify the important ideas presented in each chapter. In the Eleventh Edition, we have improved
readability by examining the chapter organization and flow and by
writing in a more personal style. Significant portions of several
chapters were substantially rewritten in an effort to make the material more understandable.
Maintaining a Focus on Basic Principles
and Instructor Flexibility
The main focus of the Eleventh Edition remains the same as in the
first ten: to foster student understanding of basic geological principles. As much as possible, we have attempted to provide the reader
with a sense of the observational techniques and reasoning
processes that constitute the discipline of geology.
The organization of the text remains intentionally traditional.
Following the overview of geology in Chapter 1, we turn to a
discussion of Earth materials and the related processes of volcanism
and weathering. Next, we explore the geological work of gravity, water,
wind, and ice in modifying and sculpting landscapes. After this look at
external processes, we examine Earth’ s internal structure and the
processes that deform rocks and give rise to mountains. The text
concludes with chapters on geologic time, Earth history, and global
climate change. This organization accommodates the study of minerals
and rocks in the laboratory, which usually comes early in the course.
Realizing that some instructors may prefer to organize their
courses somewhat differently, we made each of the chapters selfcontained so that they may be taught in a different sequence. Thus,
the instructor who wishes to discuss earthquakes, plate tectonics,
crustal deformation, and mountain building prior to dealing with
erosional processes may do so without difficulty. We also chose to
provide a brief introduction to plate tectonics in Chapter 1 so that
this important and basic theory could be incorporated in
appropriate places throughout the text.
A Strong Visual Component
Geology is highly visual, so art and photographs play a critical role
in an introductory textbook. As in the ten previous editions Dennis
Tasa, a gifted artist and respected geological illustrator, has worked
closely with the authors to plan and produce the diagrams, maps,
graphs, and sketches that are so basic to student understanding.
Dozens of the figures are new or redrawn. The result is art that is
clearer and easier to understand.
Our aim is to get the maximum effectiveness from the visual
component of the book. Michael Collier aided us greatly in this
quest. Dozens of his extraordinary aerial photographs are used in
the new edition. Michael is an award-winning geologistphotographer. Among his many awards is the American Geological
Institute Award for Outstanding Contribution to the Public
Understanding of the Geosciences. We are fortunate to have had
Michael’ s assistance in Essentials of Geology, Eleventh Edition.
New to the Eleventh Edition
• Significant updating and revision of content. With the goal of
keeping the text current and highly readable for beginning
students many discussions, case studies, and examples have
been revised. See the section on Revised and Updated Content
for many of the particulars.
• An all-new chapter on Global Climate Change. Chapter 20
looks at many links between geology and the climate system.
It examines how climate change is detected and, after an
overview of atmospheric “basics,” explores several important
natural causes of climate change. The chapter concludes with
an up-to-date examination of human impact on global
climate—a critical global environmental issue. The chapter
includes a rich array of graphs, diagrams, maps, and images.
• An even stronger art program. Dozens of figures are new or
redrawn. The result is art that is clearer and easier to understand. Numerous diagrams and maps are paired with photographs for greater effectiveness. Many new and revised art
pieces also have additional labels that “narrate” the process
being illustrated and/or “guide” readers as they examine the
figure.
• More than 150 new, high-quality photos and satellite images.
New “Geologist’ s Sketch” illustrations accompany many
important photographs and satellite images. Each sketch,
which resembles what a geologist might put in a field notebook, helps the student identify important and sometimes
subtle aspects of an image. This author–artist collaboration
helps make an already strong visual component even stronger
and more effective.
• An improved design. Anyone familiar with the previous edition will notice that we have continued the user-friendly
“look.” The design makes even more effective use of the wider
pages. The placement and integration of photographs and art
is less traditional and more creative. The scattering of Did You
Know? items through each chapter adds interest. The authors
and editors feel the improved design provides a more effective
and engaging visual impact.
Revised and Updated Content
The Eleventh Edition of Essentials of Geology represents a thorough
revision. Every part of the book was examined carefully with the
dual goals of keeping topics current and improving the clarity of
text discussions. Those familiar with the previous edition will see
much that is new. The list of specifics is long. Examples include the
following:
• Much of Chapter 2, “Matter and Minerals,” was rewritten in
an effort to make a sometimes difficult (chemistry-oriented)