Isopachous studies of formation intervals within the Permo-Pennsylvanian systems of the Anadarko basin reveal marked change in depositional strike of the beds, thus indicating a progressive shift in axis of sedimentation in the basin.

The purpose of this paper is to direct attention to this condition and to indicate its importance in helping to solve many of the structural and stratigraphic problems in the Anadarko basin.

Variable rates of subsidence in the basin as reflected by ratios of thickening of individual units are shown by regional convergence studies of the area. Structural features are also revealed by this convergence mapping.

The change in axis of sedimentation in the Anadarko basin was of a gradual nature and conforms with no individual system, series or group boundary. Since these boundaries commonly lose their identity over broad areas, it becomes more convenient to map intervals between easily identified markers within the section in order to get an accurate over-all view of sedimentary conditions in the basin.

Positive correlation of beds in the Upper Mississippian (Chester) and the Lower Pennsylvanian (Atoka-Morrow-Springer) with their equivalents on the outcrop, and the placing of unconformable relationships within this section, remain unsolved problems in the Anadarko basin. This is due primarily to lack of well control in the depths of the basin. The author has inferred a set of correlations for this section from this study. A review is given of the various arguments and correlations concerning this all-important interval, pointing out the strong points and incongruities in each.

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