Micropaleontological studies in the Iowa geologic section have been gaining impetus in the past few years, but no previous attempt has been made to assemble the accumulated information. The value of microfossils in defining and correlating stratigraphic units is generally accepted. This paper is a compilation of existing information in an attempt to establish preliminary fauna zones. Where diagnostic fossils for the various zones were not indicated by the original author we have chosen them according to relative abundance and unique occurrence, if possible. In some instances inadequate data limit the application of this method, and require listing of a larger part of the assemblage than would otherwise be necessary. Available data permit zoning of the Ordovician, Devonian, and Pennsylvanian, as shown on the following charts.
Proceedings of the Iowa Academy of Science
©1949 Iowa Academy of Science, Inc.
Thomas, L. A. and Balster, C. A.
"Micropaleontological Zones in Iowa,"
Proceedings of the Iowa Academy of Science, 56(1), 235-240.
Available at: https://scholarworks.uni.edu/pias/vol56/iss1/32