In its broader, or continental, relationships, the chronologic position of our Iowa Productive coal measures assumes an altogether different aspect from that heretofore commonly presented, and that is implied by their incorporation under the title of Pennsylvanian series. Recent physiographic and diastrophic analysis separates completely our Des Moines coal measures, of the continental interior region, from the typical Pennsylvanian coal section of the Atlantic border.
Proceedings of the Iowa Academy of Science
©1938 Iowa Academy of Science, Inc.
"Chronologic Setting of Des Moines Coal Measures,"
Proceedings of the Iowa Academy of Science, 45(1), 164-165.
Available at: https://scholarworks.uni.edu/pias/vol45/iss1/33