Quaternary geology, loess, Loess Hills, landscape development, landuse hazards, soil engineering
The narrow ridges and steep bluffs which extend in a narrow band along the Missouri Valley form the Loess Hills region. These bluffs stand in sharp contrast to the flat-lying Missouri River floodplain. The unique ridge forms are composed of thick accumulations of late Wisconsinan wind-blown silt (loess). Older Quaternary deposits as well as Cretaceous and Pennsylvanian bedrock outcrop beneath the loess in the region. The intricate texture of the topography results from the combined effects of eolian deposition, fluvial erosion, and mass-wasting. Physical properties of loess allow it to maintain nearly vertical faces when exposed. These properties also produce special problems: slope instability, severe gullying, and high erosion races. The high relief and rough terrain provide slope aspects which vary widely in exposure to sun, wind, and moisture. These factors have produced a mosaic of microenvironments noted for their unusually xeric ecology.
Proceedings of the Iowa Academy of Science
© Copyright 1986 by the Iowa Academy of Science, Inc.
Bettis, E. Arthur III; Prior, Jean C.; Hallberg, George R.; and Handy, Richard L.
"Geology of the Loess Hills Region,"
The Proceedings of the Iowa Academy of Science: Vol. 93:
, Article 4.
Available at: http://scholarworks.uni.edu/pias/vol93/iss3/4