Physical Geology  is a straightforward, easy-to-read introduction to geology both for nonscience majors and for students contemplating majoring in geology. The organization of the book is traditional and matches the organization of most lab manuals. The book contains more information than can be normally covered during a college term. This provides flexibility for the instructor who wishes to emphasize some topics while covering other topics superficially. It is also useful to the student who wants to pursue topics beyond what is covered in the classroom.

The Updated Internet Eighth Edition expands and improves upon the use of electronic resources (the Internet and the enclosed CD-ROMs). We have also taken the opportunity to improve the text and illustrations, based on suggestions from a panel of reviewers.

The upgrading of the World Wide Web section at the end of each chapter should make it easier and more meaningful for the student to enrich his or her knowledge through the World Wide Web. We have listed websites that we personally checked for usefulness. We have replaced website listings that are inactive or obsolete with new and better sites. The universal resource locators (URLs) are printed in blue and are easier to read.

Obsolete or defunct websites will be so noted. To help students effectively and efficiently use the Internet, we include step-by-step procedures and pose questions. The primary purpose of the questions is to guide students through thinking about the topic at hand. We expect that many students will explore topics beyond where we have led them.

Also integrated into this updated edition is David McConnell’s The Good Earth, an Internet Resource for Introductory Geology. This digital method of teaching will give students a more "hands-on" approach to learning geology. The Good Earth is organized into chapters, with animations used to explain certain processes. Chapter summaries, quizzes, exercises, and web links to related websites are also included. Look for the post-it notes on chapter opener pages to find out how The Good Earth can help you understand geology.

Other changes to this updated version include replacement of many photos and fine-tuning the artwork. Recent major disasters, such as the devastating earthquakes in Taiwan and Turkey, and the tsunami in New Guinea are incorporated. We now use "numerical age" rather than "absolute age" in the geologic time chapter.

Journey Through Geology (the two CD-ROMs that accompany this book) is an exciting supplement. This was produced in partnership with The Smithsonian Institution. "Interacting with Journey Through Geology" at the end of each chapter has questions to help the student get the maximum benefit from use of the disks. We have added to and improved on these questions in this updated version of the book.

Some of the changes we made for the eighth edition (relative to the seventh edition) follow. Chapters 3 and 4 have been reversed. Chapter 3 is on igneous rocks, intrusive activity, and the origin of igneous rocks, whereas chapter 4 is about volcanic activity. We have taken pains to be sure either chapter could be covered before the other. Other chapters or groups of chapters have been written to be as self-contained as possible allowing the instructor to reorganize the chapter sequence if desired. We have taken a number of descriptions and examples of geologic resources from the final chapter of the book and integrated them into appropriate chapters elsewhere in the book. The rock cycle (in chapter 2) has been expanded to include a plate tectonic example. The discussion of the origin of magmas at convergent boundaries places more emphasis on the current view by researchers that mafic magmas are generated in the asthenosphere above the subducted oceanic crust. In the chapter on geologic time we have introduced the term "actualism" and discussed why it might be preferable to "uniformitarianism." In the metamorphic chapter we have related foliation to the modern concept of gravitational collapse and spreading. We moved unconformities from the structural geology chapter to the geological time chapter. A section on changing concepts of the age of the earth has been added. The relationship between isotopic dating and the geologic time scale has been expanded. The 1996 (and 1999) rockfall at Yosemite is used as an example of mass wasting. The stream chapter underwent a major revision and now includes an expanded discussion of flooding with examples from the 1997 floods in the upper Midwest and California. In the structure chapter, the section on stress and strain and the behavior of rocks was rewritten and new examples and figures are included to clarify these difficult concepts. An appendix listing commonly used prefixes, suffixes, and root words was added.

We added new boxes on water and ice—molecules and crystals, flight hazards associated with volcanoes, the eruptions on Montserrat compared to the disastrous eruption that destroyed St. Pierre on Martinique in 1902, the Bingham Canyon copper mine, highlights of biological evolution through time, the meteorite from Mars with possible signs of fomer life. A box on water beneath glaciers describes the recently discovered lake beneath the East Antarctic Ice Sheet, surging glaciers, and subglacial volcanism and flooding in Iceland. The stream chapter includes boxes on the planned flood in the Grand Canyon and how the recurrence interval of large floods is calculated. The structure chapter includes a box on how to find oil and the salt dome box has been expanded. The interior of the earth chapter now includes a box on the spinning inner core. In the mountains chapter we added a box on a systems approach to understanding mountains and expanded a former box, retitling it "Dance of the continents (with SWEAT)."

Supplements to Accompany Physical Geology, Eighth Edition:

Additional classroom tools include:

We have tried to write a book that will be useful to both students and instructors. We would be grateful for any comments by users, especially regarding mistakes within the text or sources of good geological photographs.

We would like to thank Susan Slaymaker for writing the original boxed material on planetary geology, and Judi Kushick for writing the questions to accompany the Journey Through Geology CD-ROM.

We are also very grateful to the following reviewers of the seventh and eighth editions of this text for their careful evaluation and useful suggestions for improvement

N. L. Archbold Western Illinois University

Victor R. Baker The University of Texas

Joan Baldwin El CaminoCollege

Alexander R.Ball Los Angeles Valley College

Paul G. Bauer Cuesta College

Kenneth A. Beem Montgomery College

Robert E. Behling Western Virginia University

Terrill R. Berkland Central Missouri State University

David J. Berner Normandale Community College

Peter E. Borella Riverside CityCollege

Ted Bornhorst Michigan Technological University

David P. Bucke University of Vermont

Reid L. Buell Caltrans

Gary Carlson Midland Lutheran College

Roseann Carlson Tidewater Community College

Greg S. Conrad Sam Houston State University

Peter Copeland University of Houston

Kevin Cornwell California State University at Sacramento

Larry Davis St. John’s University

Paul A. Dike Glassboro State College

Steven F.Dodin Community College of Allegheny County

Robert J. Elias University of Manitoba

Stanley C. Fagerlin Southwest Missouri State University

Peter Fisher California State University

RonaldC. Flemal Northern Illinois University

Richard A. Flory California State University at Chico

Robert D.Forester Collin County Community College

M. G. Frey University of New Orleans

John S. Galehouse San Francisco State University

Heather L. Gallacher Cleveland State University

Lloyd Glawe Northeast Louisiana University

Andrew J. Hajash Texas A&M

Frank M. Hanna California State University—Northridge

Stephen B. Harper East Carolina University

Stephen L. Harris California State University at Sacramento

BarryHaskell Los Angeles Pierce College

Miles O.Hayes University of South Carolina

Richard A. Heimlich Kent State University

Timothy Horner California State University at Sacramento

Mary S. Hubbard Kansas State University

Roy L. Ingram University of NorthCarolina

Clark M. Johnson University of Wisconsin—Madison

Norris W. Jones University of Wisconsin—Oshkosh

Manfred Kehlenbeck Lakehead University

James G. Kirchner Illinois State University

Lawrence W. Knight William Rainey Harper College

Ronald H. Konig University of Arkansas

Albert M. Kudo The University of New Mexico

Howard Level Ventura College

David N. Lumsden Memphis State University

Harmon D. Maher, Jr. University of Nebraska at Omaha

Donald Marchand, Jr. Old Dominion University

Kathleen Marsaglia University of Texas at El Paso

James McLelland Colgate University

William S.McLoda Mountain View College

Margaret E. McMillan University of Arkansas at Little Rock

C. Daniel Miller U.S. Geological Survey

William D. Orndorff Concord College

Bruce C. Panuska Mississippi State University

Jacqueline Patterson California State University, Fullerton

David R. Privette Central Piedmont Community College

Frederick J. Rich Georgia Southern University

Gary D. Rosenberg Indiana University—Purdue University at Indianapolis

Robert A. Schiffman Bakersfield College

Vernon P.Scott Oklahoma State University

Barbara Sherriff University of Winnipeg

Charles R. Singer Youngstown State University

Kenneth G. Smith Dallas Baptist University

William A. Smith Grand Valley State University

Richard Smosna University of West Virginia

Steven Stearns College of Charleston

Don W. Steeples University of Kansas

Dion C. Stewart Adams State College

M. Ali Tabidian California State University, Northridge

Norman W. Ten Brink Grand ValleyState College

J. Robert Thompson Glendale Community College

Daniel R. Tucker University of Southwestern Louisiana

Sherwood D. Tuttle University of Iowa

Kenneth J. Van Dellen Macomb Community College

W. R. Van Schmus University of Kansas

Stephen Wareham California State University at Fullerton

Stephen H. Watts Sir Sanford Fleming College

William J. Wayne University of Nebraska

Thomas H. Wolosz SUNYCollege of Plattsburgh

A special thank you to the ’97 GSA Focus Group:

Scott Babcock Western Washington University

Drew Coleman Boston University

Ralph Davis University of Arkansas

Megan Jones University of Minnesota and Inver Hills Community College

Michael Katuna College of Charleston

Peter Kresan University of Arizona

James Miller Southwest Missouri State University