Union County already occupies a notable place in the annals of the Pleistocene geology of our State. Near the towns of Thayer and Afton Junction are exposed the gravel beds which first furnished the basis for the separation of the drift of the pre-Kansan age from that of the Kansan, and for the establishment of the Aftonian interglacial interval The name of this latter age of American geology was taken from the town of Afton which is located not far from the above mentioned gravel exposures, in Union county.
Proceedings of the Iowa Academy of Science
©1903 Iowa Academy of Science, Inc.
Savage, T. E.
"A Buried Peat Bed in Dodge Township, Union County, Iowa,"
Proceedings of the Iowa Academy of Science, 11(1), 103-109.
Available at: https://scholarworks.uni.edu/pias/vol11/iss1/15