To begin, we define soil as the weathered and fragmented outer layer of the earth’s terrestrial surface. It is formed initially through disintegration, decomposition, and recomposition of mineral material contained in exposed rocks by physical, chemical, and biological processes. The material thus modified is further conditioned by the activity and accumulated residues of numerous microscopic and macroscopic organisms (plants and animals). In a series of processes that may require hundreds or even thousands of years and that is called soil genesis, the loose debris of rock fragments is transmuted into a more or less stable, internally ordered, actively functioning natural body. Ultimately, this culminates in the formation of a characteristic soil profile, which resembles a layer cake. We can visualize the soil profile as a composite living body, in the same way that we think of the human body as a distinct organism, even though in reality it is an ensemble of numerous interdependent and symbiotically coordinated groups of organelles, cells, organs, and colonies of myriad organisms. <...>

The urge to make geology more quantitative has led to the widespread inclusion of chemistry, physics, and mathematics—the so-called "basic" sciences—among the required courses in undergraduate curricula. One can only applaud this practice, for certainly many of the new and exciting ideas in earth science have come from application of quantitative reasoning to geologic problems. It is reasonable to ask. however, if the mere requiring of courses in basic science is an efficient way to give most students facility in handling ideas quantitatively. For the few who take easily to mathematical symbolism, the answer would be "yes":

The elementary student of geology may well first encounter the basic elements of structural geology through the study and interpretation of geological maps. However, there are few if any textbooks on structural geology which concentrate on showing how the forms of geological structures can be determined from the evidence presented by a geological map, even although such an analysis is fundamental to their interpretation. Admittedly, there are several laboratory manuals on the British market which offer a very elementary introduction to the basic methods used in the interpretation of geological maps.

This volume, Introduction to Geophysical Formation Evaluation, is intended as a practical volume for the engineer, environmentalist, geologist, miner, exploration manager, and student. Although it contains some relatively detailed analyses, it is not intended to be used to design geophysical instruments, but rather, how to use them. Its focus is on the petroleum usage of geophysical methods: petroleum-funded research and engineering is where about 90% of present-day geophysical methods originate. Non-hydrocarbon methods and practice, as well as other-than-borehole methods are planned for subsequent books. It is important to know where these methods originate.