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, geology instructors have relied on this text for over 5,000 courses to explain,  illustrate, and exemplify basic geologic concepts to both majors and nonmajors. Today, the 9th 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.  <...>

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. <...>

Petrophysics, beginning with Archie’s historical yet evergreen equations, has a key function in all applications of geosciences, petroleum engineering and related technologies. It helps us to understand the processes and controlling properties and creates relationships between parameters we can measure as output of the dramatic progress in exploration techniques and properties we need for reservoir characterization (hydrocarbons, water, minerals, geothermal energy), exploration of natural resources, geotechnical constructions and environmental protection.

Geology is the study of the Earth in all its aspects except those that are now considered to be separate sciences of the Earth, like geophysics and meteorology. It concerns the materials of which the Earth is made, and the processes that operate on them. Very many of these processes are physical, and their understanding involves an understanding of the underlying physics. The raindrop that falls and makes its contribution to erosion is first created by condensation, falls under the influence of gravity, is held together by surface tension, reaches its terminal velocity as a result of friction long before hitting the Earth, has potential energy during its fall, and kinetic energy that is converted to mechanical energy and work when it strikes the Earth. <...>