Graduation Semester and Year

2008

Language

English

Document Type

Thesis

Degree Name

Master of Science in Earth and Environmental Science

Department

Earth and Environmental Sciences

First Advisor

Merlynd K Nestell

Abstract

Diffuse reflectance spectroscopy was used to determine the relative abundance of the iron oxides hematite and goethite in a loess and paleosol sequence from an unglaciated area of southern Illinois. Factor analysis of first derivatives of the spectral data yielded a four factor solution which explained more than 94% of the cumulative variance. Factors 2 and 3, which represent hematite and goethite respectively, were the most useful for interpreting paleoclimatic conditions at the site. Hematite, which is indicative of warmer conditions with periodic seasonal rainfall, shows a strong response not only to climatic variations but also to glacial lobe proximity. Goethite is generally associated with loess where conditions favored a cooler and moister environment and exhibits a strong correlation to glacial intervals with the exception of the Roxana loess, where large amounts of quartz and secondary carbonate interfere with the signal. Together, factor 2 (hematite) and factor 3 (goethite) illustrate a paleoclimatic record of southern Illinois for the last 11 glacial/interglacial episodes.

Disciplines

Earth Sciences | Physical Sciences and Mathematics

Comments

Degree granted by The University of Texas at Arlington

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