Earth and Atmospheric Sciences, Department of
Date of this Version
12-1939
Citation
American Journal of Science VOL. 287, No. 12, DECEMBER, 1989. PP. 851-884.
Abstract
Nebraska is so peculiarly situated with respect to Pleistocene deposits of glacial, fluviatile, and eolian origin that it holds the key to the solution of many important problems of the stratigraphy of that period. A brief outline of the Pleistocene geology of Nebraska with several illustrations is followed by a statement of and brief discussion of several of these problems. The main problems touched upon are: age of the Loveland loess, Pleistocene classification, correlation with Europe, the need for a better understanding of what is meant by "glacial" and "interglacial," the problem of glacial and interglacial loess, the duration of the glacial advances, post-Loveland pre-Peorian erosion, the geomorphology of the Great Plains as an aid in understanding Pleistocene history, sources of loess materials, the relation of river valleys to the origin and deposition of the loess, the significance of the lesson of the dust storms, the "Citellus" zone and the antiquity of Man, problem of animal survival and Pleistocene faunal succession, what constitutes the Aftonian fauna, and the problems of varved sediments. Pleistocene geology still is in the "experimental" stage.