The Coffeyville interval within the Missourian Series of the Pennsylvanian System in northeastern Oklahoma was studied to determine its origin. The interval is an isochronous unit underlain by the Checkerboard limestone key bed and overlain by the Hogshooter limestone. Through most of the area these transgressive limestone marker beds define a time-rock unit.

Stratigraphic characteristics within the interval are illustrated by cross sections, and specific data obtained from more than 500 well logs were used to make isopachous, sandstone-shale ratio, and isolith maps. Core, E log, and outcrop observations provided information on sedimentary structures, textures, and vertical sequences.

The primary depositional framework is deltaic. From the available data it is possible to delineate 8 separate environmental facies within the delta complex, and to correlate each facies with particular S.P. curve shapes. Outcrop and core studies of trace fossils, textures, and sedimentary structures were correlated to individual facies. Criteria were established to recognize ancient deltaic deposits and methods of environmental analysis.

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