Were the Appalachian and Eastern Interior Coal Fields ever connected ? There are probably very few men interested in coalmining to whom a close scrutiny of a coal map. of the eastern United States has not suggested this interesting question. By the earlier geologists the former continuity of the two fields was assumed without question and the Pennsylvania names of sandstones were often applied to the sandstones in Illinois, Indiana, and Kentucky. The fact that the two fields are separated by

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... tle more than 6 5 miles in central Kentucky, and that this gap is over the arch of the Cincinnati antic'line, the crest of which has been removed during successive periods of peneplanation, gives color to such an assumption. Again, a comparison of the western edge of the Appalachian field in Kentucky with the eastern edge of the Illinois field discloses many points of resemblance. In northeastern Kentucky the western edge of the coal field consists mainly of a massive sandstone comprising one or two members, with two or three coal beds of small importance. Similar massive sandstones of about the same thickness make up most of the coal measures along the eastern edge of the Illinois field in Indiana, and a comparison of their fossils indicates that they are approximately of the same age. The massive sandstone so prominent at the western edge of the Appalachian field,