Age Relationship of Wavy‐Gilgaied and Nongilgaied Soils in Western South Dakota

Abstract

AbstractThe incidence of wavy‐gilgaied, nongilgaied‐Chestnut, and lithosolic soils formed from Pierre shale was estimated at intervals in a creek valley by a transect method to test the concept that the three soils form a chronosequence. Recent geologic erosion was found to decrease progressively up the valley. The distribution of both the wavy‐gilgaied soil and the lithosolic soil in the valley was significantly related to the extent of the recent geologic erosion. The distribution of nongilgaied‐Chestnut soils was not significantly related to the amount of erosion along the valley. Wavy‐gilgaied soils were most abundant where erosion was least and thus the soil age was greatest, whereas Lithosols were most abundant where erosion was greatest and thus the soil age was least. Chestnut soils occurred in both locations, presumably where the soil age was intermediate.