Most of the easy-to-find petroleum accumulations in the United States have been discovered. As a result, domestic exploratory successes during the past decade have been declining not only in the number of fields found annually, but also in quality or economic worth. This has happened because the petroleum industry is still exploring principally for the obvious types of traps which it knows are becoming scarcer and thus harder to find.

Many geologists have made relatively little purposeful effort to search for hidden trends and subtle traps--stratigraphic or paleogeomorphic--because (1) their training has conditioned them to look for structures with present-day tools and ideas and (2) management is more likely to "buy" a prospect if it is an anticline, dome, or fault structure.

Hidden trends and subtle traps are present in a variety of situations--structural, stratigraphic, and paleogeomorphic. Many probably can now be found, but only if geologists direct their methods of attack toward them, not around them. Unless exploration now and in the future is designed to find and drill hidden trends and subtle traps, the large domestic reserves required for the future will not be found. Both geologists and management must reorient their thinking toward this end.

The Gulf coastal province is an ideal area in which to search for subtle or hidden traps. Among the situations which deserve attention are (1) sandstone pinch-out in the lagoonal environment of the Frio (Oligocene-Miocene) of south Texas, (2) buried structures and sandstone buildups in the Hackberry embayment (Oligocene-Miocene) of southeast Texas and southwest Louisiana, (3) favorable sandstone distribution patterns in the downdip Wilcox (Eocene) from Mexico to Alabama, (4) undiscovered accumulations of petroleum in relict traps around salt domes, and (5) paleogeomorphologic features which doubtless are present in the entire Gulf coastal province.

The time has come for domestic explorationists to look purposefully for the hidden trend and the subtle trap. Because such a change in approach requires management concurrence and support, the geologist and geophysicist must convince management to explore for such features. Moreover, it is management's responsibility to change with the times and to support necessary changes in exploration techniques. If geologists, geophysicists, and management--together--are willing the United States petroleum industry will be rewarded with a new era of successful exploration.