In the last generation or two there appears to have been little advancement made along lines of general geologic correlation. Two controlling reasons stand out prominently. On account of the fact that the criterion of fossils is so largely misused and is so generally unchecked by other critical criteria it is continually losing much of its former precedence. The adoption of the lithologic formation as the cartographic unit is also almost a complete failure for the reason that no account is taken of the change, replacement and effacement of its essential characters from place to place. All this confusion gives rise to an interminable synonymy which even a specialist in a circumscribed region cannot always satisfactorily make out without detailed review of the original sections on the ground.
Proceedings of the Iowa Academy of Science
©1915 Iowa Academy of Science, Inc.
"Remarkable Prairie Synclinorium,"
Proceedings of the Iowa Academy of Science, 22(1), 268-271.
Available at: https://scholarworks.uni.edu/pias/vol22/iss1/33