In connection with the extensive program of road improvement now in progress in Iowa, the State Highway Commission has conducted a rather detailed survey of the resources of road material within the state. In the southern half of Iowa, where such materials are most scarce, the survey has been most intensive. Not only have the superficial deposits been investigated, but the indurated rocks have also been carefully studied, both from their natural outcrops, and from the records of wells, mine shafts, etc.
Proceedings of the Iowa Academy of Science
©1930 Iowa Academy of Science, Inc.
Wood, L. W.
"Road Materials from the Des Moines Series of the Pennsylvanian System of South-Central Iowa,"
Proceedings of the Iowa Academy of Science, 37(1), 267-271.
Available at: https://scholarworks.uni.edu/pias/vol37/iss1/56