Paper discussing the geology of the Devonian shales and the potential locations of gasses within it.

From the paper: "The internal stratigraphy of almost any sedimentary resource – be it a coal bed, an evaporite, or an aging oil field programmed for secondary recovery - is a vital first step for evaluating its full resource potential. Because this is also true of the gas potential of the Upper Devonian black-shale sequence of the Appalachian basin, we have identified and named a useful marker bed, the Three Lick Bed, in the upper part of the Ohio Shale and its equivalents in eastern Kentucky and in nearby Ohio, West Virginia, and Tennessee. The Three Lick Bed consists of three greenish-gray shale beds separated by fissile, brownish-black shale. These distinctive greenish gray shale beds are easily recognized in outcrop in seven sections on the east flank of the Cincinnati arch from southern Ohio into Tennessee, have a distinctive signature on wire-line logs, and can be identified in well cuttings over much of eastern Kentucky and adjacent parts of Ohio and West Virginia. The Three Lick Bed correlates with the middle unit of the Gassaway Member of the Chattanooga Shale in Tennessee and with the lower part of the Camp Run Member of the New Albany Shale in Indiana."