ABSTRACT

The surface has been largely neglected in the search for oil and gas in the Anadarko basin. This is understandable because the surface is composed essentially of Upper Permian strata laid down subsequent to the major mountain-building forces affecting the region. In places the Permian rocks are mantled by moderately-indurated Tertiary continental beds and unconsolidated Quaternary deposits.

A recently-completed detailed photogeologic-geomorphic evaulation study revealed considerable evidence that the surface offers numerous clues to subsurface geologic conditions. The study involved comprehensive stratigraphic and structural mapping by conventional photogeologic techniques supplemented by detailed geomorphic structural analysis.

This phase, or, "applied geomorphology", is concerned with determining the degree of influence that structure and lithology have had on the morphologic development of the region. Basic geologic-geomorphic relationships are established and "interruptions" to the regional geomorphic "norm" are often interpreted as diagnostic clues to anomalous subsurface geologic conditions. The results in the Anadarko basin indicate that many deep-seated structural anomalies are reflected at the surface in the drainage, land form, erosional, phototonal and (or) fracture patterns.

The study was enhanced by the use of a special-purpose aerial photography taken with the Wild RC-9 Camera. This photography has many advantages over conventional aerial photography and is especially well suited to low-dip mapping. As a result of its 6.5X exaggeration factor, an actual dip of one degree is exaggerated in the stereoscopic view to about 6.5 degrees. This permitted reliable mapping of very low-relief features in the Anadarko basin, where the dip rarely exceeds one degree.

Four producing areas, with subsurface control used for comparative purposes, are examined as examples of surface reflections of deep structure. These are the (1) Cement, (2) Apache, (3) Gageby Creek and (4) Washita Creek Fields.

The close correlations between surface and subsurface structure in these and a number of other areas reviewed indicate that the surface should no longer be ignored as a source for clues to potential oil/gas traps.