The Post-Kansan Geologic History of the Lower Platte Valley Area

Authors

Gilbert Carl Lueninghoener, University of Nebraska

Date of this Version

9-1947

Citation

UNIVERSITY OF NEBRASKA STUDIES, September 1947, NEW SERIES NO. 2

Comments

(c) 1947 University of Nebraska

Abstract

This investigation is essentially a geomorphological study of the lower Platte River Valley area in eastern Nebraska. The area comprises Saunders, Dodge, Washington, Douglas, Sarpy, and Cass counties. The area defined above is one of the most critically located of any for the study of the post-Kansan history of the lower Platte River Valley. It lies between the older till (Nebraskan and Kansan) borders to the west and the younger till (Illinoian, Iowan, and Wisconsin) borders to the east. Physiographic changes have therefore transpired in a strictly post-Kansan periglacial region. The Kansan till is the youngest in the area. The area includes Todd Valley, which is an old abandoned Platte River Valley of great significance in interpreting the post-Kansan history. The purpose of this research is to establish the chronological order of events in terms of erosions and depositions that have transpired since the melting and disappearance of the ice of the Kansan age of glaciation.

Introduction 5 / Procedure 7 / Physiographic Description 9 / Stratigraphic Units 16 / Profile Sections 19 / Post-Kansan History 58 / Post-Kansan Pre-Crete Cycle 58 / The Crete-Loveland Cycle 59 / Todd Cycle 61 / Fort Calhoun or "Peorian" Cycle 61 / Linwood Cycle 71 / Fremont Cycle 72 / Elm Creek Cycle 72 / Present Cycle 72 / Summary 73 / General Conclusions 78 / Bibliography 79