Cyclic upper Paleozoic deposits in the northern Mid-Continent region have long challenged the ingenuity of geologists seeking a rational interpretation of their origin. Most theories have been based principally on the vertical succession of lithologic features in stratigraphic sequences hundreds of feet thick. The present study of the Beattie limestone (Wolfcampian) is based on the conviction that additional clues to an understanding of depositional environments can be gained by studying in detail thin stratigraphic units as they change facies across a depositional basin. The three 'members of the Beattie (in ascending order. Cottonwood limestone, Florena shale, Morrill limestone) have been examined in outcrop from Nemaha County, Nebraska to Osage County, Oklahoma and fol owed in the subsurface

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westward nearly to Colorado. Regional paleotectonic studies indicate that the line of outcrop runs almost from shore to shore diagonally across an elongate seaway extending from northeastern Wyoming southeastward to northeastern Oklahoma. Thirteen distinct facies of the Beattie are recognized, based on mineralogic, paleontologic, petrographic, and field data. Two facies provinces with a boundary in central Greenwood County, Kansas, are clearly indicated. Basin topography is demonstrated to be the prime controlling influence on the distribution and nature of the facies. Simple transgression-regression explanations are not adequate to explain observed facies patterns in the Beattie limestone.

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