With their extreme simplicity of geological structure it seems almost incredible that the coal-fields of the Continental Interior should remain so long without even approximate correlation of their several parts. That the Arkansas district, the Western Interior area, the Eastern Interior field and the Michigan basin are essential parts of a single stratigraphic province there is now little reason to doubt. Recent regional planation manifestly separates a once continuous plate by removing the coal measures over the crests of broad gentle folds and preserving from the effects of erosion the deposits lying in the troughs.
Proceedings of the Iowa Academy of Science
©1918 Iowa Academy of Science, Inc.
"Provincial Unity of Continental Interior Coal Fields,"
Proceedings of the Iowa Academy of Science, 25(1), 545-550.
Available at: https://scholarworks.uni.edu/pias/vol25/iss1/51