DOI

10.17077/etd.0cest0ut

Document Type

Thesis

Date of Degree

Spring 2018

Access Restrictions

Access restricted until 07/03/2019

Degree Name

MS (Master of Science)

Degree In

Geoscience

First Advisor

E. Arthur Bettis, III

First Committee Member

David Peate

Second Committee Member

Mary Skopec

Abstract

This study is centered around the spatial distribution and age structure of PSA in a section of floodplain in the upper reaches of Clear Creek Watershed in east central Iowa. The study area topography, climate, soil, and pre-settlement tallgrass prairie landcover are representative of the headwaters of many Midwest watersheds, making the findings applicable in other parts of the region. Through this investigation, I aim to further understand the volume and age structure of PSA sediments deposited on the floodplain after Euroamerican settlement. This will be done through multiple methods: the collection and measurement of PSA in soil cores, visual and spatial analysis of land use and stream channel morphology, PSA volume calculations, and isotope geochemistry. Using 210Lead (Pb) and 137Cesium (Cs) isotope geochemistry to calculate age structures of the PSA will provide a more detailed, temporal resolution of physical data than erosion and deposition model predictions can generate. A detailed land use history will further facilitate the understanding of depositional processes that have occurred in the study area and region. By understanding the age structure of the sediment on the floodplain, as well as sediment volumes that are stored in floodplain headwaters, tangible connections can be made between agricultural land use and floodplain sedimentation rates and the impact (if any) assessed of potential conservation practices. This research is supported by the Intensively Managed Landscape Critical Zone Observatory (IML-CZO) of the National Science Foundation’s CZO network, which aims to understand how land use changes affect the long-term resilience of the critical zone, where water, atmosphere, ecosystems, soil, and bedrock interact.

Keywords

geochronology, PSA, soil

Pages

xii, 209 pages

Bibliography

Includes bibliographical references (pages 71-79).

Copyright

Copyright © 2018 Kelli Joanne Parsons

Available for download on Wednesday, July 03, 2019

Included in

Geology Commons

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