ELONGATE DRIFT HILLS OF SOUTHERN ILLINOIS
BY JOHN R. BALL
In widely separated areas throughout southern Illinois are low, elliptical hills of glacial origin. They are in the area of Illinoian glaciation and are somewhat densely segregated in the western part of the State. They probably fall into several categories as to mode of origin, including morainic, interlobate, and glacio-fluvial, but some hills which simulate the elongate drifthills are of eroded bedrock.
Salient features of common occurrence in these hills have instigated recent field studies in southwestern Illinois. The elongate drifthills surmount the uplands and are surrounded by wide expanse of flat driftplain or eroded moraines. In ground plan they are elliptical. Their long axes approximately parallel the existing drainage lines and in one or two cases the pre-glacial drainage lines.
Many of the hills show loess and till in the summit slopes and in road cuts. Others exhibit assorted . . .
- © 1939 Geological Society of America