The Coleman Junction horizon in Archer and Clay Counties, Texas

Abstract

The Coleman Junction limestone was mapped from Coleman County northward through Callahan and Shackelford counties by Plummer and Moore, and continued through Throckmorton County by Hornberger. Work presented herewith carries the Coleman Junction or its equivalent horizon through Archer and Clay counties to the River in the northeast corner of Clay County. Photographs of typical exposures and measured sections of the outcrop or its equivalent horizon are given for important points, from northeastern Throckmorton County through Archer and Clay counties to the Red River. Two small maps are included showing correlations by Hubbard and Thompson, and by Tomlinson. Four large maps are used; one each of Archer and Clay counties showing the course of the outcrop or its equivalent horizon as interpreted by the writer; and one each of Archer and Clay counties showing the interpretation by Timms for the same area. Although the tracing of the Coleman Junction or its equivalent horizon constitutes the central problem of this thesis evidence is also presented indicating that the Coleman Junction correlates approximately with the Ryan Sandstone of Oklahoma.