During the field season of 1917, the writer examined two exposures of stratified sands and gravels, which, in age, may probably be correlated with the close of the Nebraskan stage of glaciation and with Aftonian times.
Proceedings of the Iowa Academy of Science
©1919 Iowa Academy of Science, Inc.
Schoewe, W. H.
"The Interpretation of Certain Leached Gravel Deposits in Louisa and Washington Counties, Iowa,"
Proceedings of the Iowa Academy of Science, 26(1), 393-398.
Available at: https://scholarworks.uni.edu/pias/vol26/iss1/39