During the summer of 1956 the authors undertook an extensive study of the Pennsylvanian rocks exposed in Iowa and the adjacent states of Nebraska and .Missouri, in an effort to locate rock formations that would be suitable for the production of aggregate for use in highway construction work. The rocks exposed along the Middle River, that extends from the vicinity of Winterset, Madison County, to just southwest of Casey, Adair County, a distance of about 35 miles is one of the first areas that has been thoroughly investigated.
Proceedings of the Iowa Academy of Science
©1957 Iowa Academy of Science, Inc.
Welp, T. L.; Thomas, L. A.; and Dixon, H. R.
"A Correlation and Structural Interpretation of the Missourian and Virgilian Rocks Exposed Along the Middle River Traverse of Iowa,"
Proceedings of the Iowa Academy of Science, 64(1), 416-428.
Available at: https://scholarworks.uni.edu/pias/vol64/iss1/44