One excellent reason is that it's tried and true. Physical Geology: Earth Revealed is a classic in introductory geology classes that has evolved into a market-leading text read by thousands of students. Proportionately, geol- ogy instructors have relied on this text to explain, illustrate, and exemplify basic geologic concepts to both majors and non-majors. Today, the 7th edition continues to provide contemporary perspectives that reflect current research, recent natural disasters, unmatched illustrations, and unparalleled learning aids. We have worked closely with contributors, reviewers, and our editors to publish the most accurate and current text possible. The most exciting element of the new edition is the presentation of 300+ new illustrations, created by the artistic skill of Cindy Shaw. Ideas that shaped the development and articulation of new figures resulted from the numerous recommendations of a group of geology instructors. <...>

The Earth is a dynamic planet that has changed contin- uously during its 4.6 billion years of existence. The size, shape, and geographic distribution of the continents and ocean basins have changed through time, as have the atmosphere and biota. Over the past 20 years, bold new theories and discoveries concerning the Earth's origin and how it works have sparked a renewed interest in geology. We have become increasingly aware of how fragile our planet is and, more importantly, how inter- dependent all of its various systems are. We have learned
that we cannot continually pollute our environment and that our natural resources are limited and, in most cases, nonrenewable. Furthermore, we are coming to realize how central geology is to our everyday lives. For these and other reasons, geology is one of the most important college or university courses a student can take. <...>

In the example above, an observation is made and a hypothesis formulated. A hypothesis is an educated guess. Experiments are performed to prove or disprove your hypothesis. This sort of deductive reasoning is the same thought process used by detectives to solve crimes. You may consider the mineral identification experiments as simple, but there is no written rule that experiments must be complicated.
If an experiment is repeated time and time again and the conclusions are exactly the same, then the conclusion is elevated to a theory. Scientists define theory as a proven conclusion, something over which there is very little doubt. Notice that the way scientists use the word theory is much different from our everyday use. In our everyday usage, theory is equivalent to a scientist’s hypothesis—an estimation or guess. Sherlock Holmes’ theory of the murder was Colonel Mustard with the candlestick. This is Holmes’ guess or hypothesis of the crime; now he must gather evidence to prove it. <...>

Nearly everyone, at some time in his or her life, will have stood on a  sea beach and watched how the waves repeatedly disturb and then deposit the sand grains, whilst the wind, blowing freely over the drier parts of the beach, gathers up some of the sand and sweeps it inland to form tall dunes.

This particular case, one from common experience, serves very well to introduce the general topic of this book, namely, the dynamic interactions, in natural surroundings, between detrital particles and moving fluids. These interactions, in which physical processes are of paramount importance, give us the depositional landscapes and seascapes with which we are familiar today and, at various removes in time, many of the sedimentary strata found in the earth's crust <...>