The practice of modern subsurface exploration geology requires a knowledge of the fundamentals of stratigraphy. To acquire this background, the petroleum exploration geologist must have mastered the basic principles of mineralogy, sedimentary petrology, sedimentation, stratigraphie paleontology, and geomorphology. Although these subjects generally are taught as separate disciplines, they nevertheless overlap and are interrelated. A working knowledge of all these subjects is germane to understanding the problems of subsurface stratigraphy. Areas within these disciplines which merit particular emphasis are: principles of deposition, depositional environments, stratigraphie time markers, and stratigraphie and paleogeomorphic traps.
A treatment of the principles of deposition is inherent to a basic course in sedimentation. These principles are applied to a wide variety of energy environments, each of which must be considered separately to determine the type of sand body that might be deposited. A broad classification of energy environments includes four major areas of deposition: terrestrial, lacustrine, marginal marine, and marine. Each of these comprises numerous contrasting energy environments in which abundant elastic sediments accumulate. Table 1 is one classification of depositional environments.
There is much literature describing Holocene deposits formed in most of the environments listed in Table 1. A moderate amount of literature describes ancient counterparts of these environments based on outcrops.