Studies of cores from both field and wildcat wells offer the opportunity to interpret subsurface rock sequences and relate them to surface sections, to calibrate mechanical logs with observed lithologies, and to use these data to enhance both field development drilling and wildcat exploration.

The cored sequences of detrital rocks described herein are organized on the basis of depositional models, and presented sequentially down the depositional system through the continental environments to the shoreline zone, and, finally, to the shallow offshore and deeper water environments (Fig. 1.1).

Each of the depositional models is treated in a separate section in which diagrams, facies descriptions and terminology are presented that summarize the principal aspects of the model. These summary materials provide the framework for examination of the interpreted cored sequences and corresponding log suites that follow in each section. Letter symbols of depositional environments, as derived from depositional model diagrams for the section, occur on both the core photographs and the corresponding logged intervals.