CHAPTER I
INTRODUCTION
SURVEY OF FIELD
In adapting ourselves to physical environment it has been necessary to learn something about the earth. Mainly within the last century has this knowledge been organized into the science of geology, and only within the last few decades have the complex and increasing demands of modern civilization required the applications of geology to practical uses, resulting in the development of the science generally known as economic geology. This science is not sharply marked off from the science of geology proper; almost any phase of geology may at some time or some place take on its economic aspect.
The usefulness of economic geology was first recognized in relation to mineral resources,—and particularly in relation to metallic resources, their discovery and development,—but the science has been found to have much wider practical application. The practice of the economic geologist in recent years has taken on many new phases.
The geologist is called upon to study the geologic features of mineral deposits, their occurrence, structure, and origin. The basic information thus acquired is useful in estimating reserves and life of mineral deposits. This leads naturally to considerations of valuation. Because valuation plays such a large part in any tax program, the geologist is being used by tax boards of the federal and state governments.