Determining the Age of a Stabilized Dune Field

Authors

Carissa Raymond, University of Nebraska-LincolnFollow

Date of this Version

4-2016

Document Type

Poster

Citation

UCARE Poster session, University of Nebraska-Lincoln Research Fair, April 2016, Lincoln, NE.

Comments

Copyright © 2016 Carissa Raymond

Abstract

The aim of this project was to assess the development and age of the Kearney Dunefield in central Nebraska through the collection and analysis of sand samples from the inactive dunes. These dunes are not part of the well-known Nebraska Sandhills, and so far have not been thoroughly studied. Similar assessments have been conducted on dune fields throughout the Great Plains, and this study seeks to place the Kearney Dunes into a regional context.

The OSL ages for the Kearney cores fall between approximately 590 and 690 years ago. These dates overlap with a period of activation for the Nebraska Sandhills, as well as for the Duncan Dunes near Columbus, Nebraska. These events are associated with large-scale drought episodes in the Great Plains (Miao et al., 2007). Evidence for these megadroughts has also been found in Colorado and Kansas, supporting the interpretation that these are large regional events (Hanson et al., 2009). The analysis of the Kearney Dunes shows that these megadroughts also significantly affected dunefields in the Eastern Great Plains.

The Kearney cores only reach 3.5 meters in depth, and thus do not show older periods of activation. Further study is required to determine if the Dunefield was activated during other times in the past, such as those recognized in the Sandhills.