The term Aftonian was first applied by Chamberlin2 to interglacial beds of gravel and peat near Afton Junction, Iowa, under the impression that they were later than the Kansan. The first correct reference of the Aftonian to its place below the Kansan was subsequently made by Chamberlin3 after a reexamination of the type locality.
Subsequent investigations by members of the staff of the Iowa Geological Survey have shown that the Aftonian is widely distributed in the state. Peat beds belonging to this stage have been reported from Oelwein, in Fayette county;4 from Scott county (doubtfully);5 from Cedar county (doubtfully);6 from Tama county;7 from Chickasaw county;8 from Union county,9 and several additional probable localities in southern Iowa are given by Bain.10 Four species of mosses (Hypnurn)11 and the wood of a conifer (Larix) 12 have been reported from these peat . . .