DISTRIBUTION AND STRATIGRAPHY OF THE LOESS
BY EARL T. APFEL
Loess occurs as a discontinuous mantle over the central plains and in the Columbia plateau area, while scattered loess patches are found in Connecticut, Massachusetts, New York, and elsewhere. The distribution is shown on maps.
The stratigraphic loess unit is ideally that loess and associated material deposited during a single depositional cycle such as occurred during an interglacial interval. In the areas of superimposed drifts in Illinois, Iowa, and Nebraska such units have been recognized and usually named according to the interglacial interval in which they were formed.
Beyond the limits of superimposed drifts the loesses merge. A pre-Peorian erosion interval, a soil zone on the older loess, and somewhat different sources of material make Peorian loess distinguishable from that which preceded it. The name Loveland designates the pre-Peorian loess which is widespread from eastern Iowa to western Nebraska. Both . . .