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  • Provenance of Modern Soils of Middle Tennessee Assessed Using

    Zircon U-Pb Geochronology and Element Mass Fluxes

    By

    Nathan James Katsiaficas

    Thesis

    Submitted to the Faculty of the

    Graduate School of Vanderbilt University

    in partial fulfillment of the requirements

    for the degree of

    MASTER OF SCIENCE

    In

    Earth and Environmental Sciences

    December, 2014

    Nashville, Tennessee

    Approved:

    Professor John C. Ayers

    Professor David J. Furbish

  • ii

    ACKNOWLEDGEMENTS

    This study would not have been possible without financial support from Vanderbilt University’s

    Department of Earth and Environmental Sciences and from the Geological Society of America

    Southeastern Section. I would especially like to thank Dr. John C. Ayers, Dr. Calvin F. Miller, and Dr.

    Lily Claiborne, my graduate committee, who have been highly supportive of my academic goals and

    provided much-needed guidance over the course of my graduate studies. I am deeply indebted to Dr.

    Ayers, my thesis advisor and committee chair, without whom I would not have had such an exciting

    venture. He is an exemplary research scientist, and as my mentor over the past two years, has helped me

    to grow both as a scientist and as a human being. In addition, I owe a great deal of gratitude to Dr. David

    J. Furbish, who provided me a new lens through which to view earth processes and offered invaluable

    advice and assistance over the course of this research endeavor.

    Much of the data that is presented in this thesis would not be here without the tireless efforts of

    Ph.D. student and laboratory manager Aaron Covey who maintained the many instruments needed for the

    analyses in this study. Aaron was also an invaluable source of advice, knowledge, and humor, without

    whom, my experience as a graduate student would have been diminished. I am additionally grateful to

    department faculty Dr. Steven L. Goodbred, Dr. Guilherme Gualda, Dr. Daniel Morgan, and Dr. Molly F.

    Miller as well as visiting scholar Dr. Xiaomei Wang, postdoctoral-scholar Dr. Carol Wilson, and

    classmates, Dr. Susanne McDowell, Dr. Tamara Carley, Dr. Ayla Pamukcu, David Fry, and Tenley

    Banik, for their substantial assistance in the field, lab, or otherwise, throughout this project.

    None of this would have been possible without the love and support of my family, especially my

    parents, Jim and Donna, and my siblings, Jacob and Caitlin. Thank you for pushing me to follow my

    dreams and pursue new challenges. Lastly, I want to thank the entire Earth and Environmental Sciences

    department as a whole—the staff, students, and faculty—you made those two years at Vanderbilt

    University some of the best of my life.

  • iii

    TABLE OF CONTENTS

    Page

    ACKNOWLEDGEMENTS ..........................................................................................................................ii

    LIST OF TABLES .......................................................................................................................................vi

    LIST OF FIGURES ....................................................................................................................................vii

    Chapter

    I. INTRODUCTION .................................................................................................................................. 1

    Soil Development in Limestone Terranes ............................................................................................... 1

    Island Carbonates ............................................................................................................................... 1

    Siliceous Carbonates ........................................................................................................................... 1

    II. STUDY LOCATION AND SITE DESCRIPTION ............................................................................... 4

    Study Location and Geologic Setting .................................................................................................... 4

    Field Sites ................................................................................................................................................ 5

    Site 1: Harpeth River Terrace ............................................................................................................. 6

    Site 2: Highway 840 Outcrop .............................................................................................................. 8

    III. METHODS .......................................................................................................................................... 10

    Sample Collection ................................................................................................................................ 10

    Sample Preparation .............................................................................................................................. 11

    Soil Samples ...................................................................................................................................... 11

    Bedrock Samples ............................................................................................................................... 12

    Loss on Ignition (LOI) ......................................................................................................................... 14

    X-ray Diffraction (XRD) ..................................................................................................................... 15

    Standard Mineral Separation ................................................................................................................ 15

    Zircon Acid Cleaning ........................................................................................................................... 17

    Hand-picking and Mount Preparation .................................................................................................. 18

  • iv

    Analytical Methods .............................................................................................................................. 18

    Trace Element Analyses .................................................................................................................... 18

    Geochronological Analyses .............................................................................................................. 19

    IV. RESULTS ............................................................................................................................................ 20

    Soil Characteristics .............................................................................................................................. 20

    Bulk Properties ..................................................................................................................................... 22

    XRD Analyses ...................................................................................................................................... 24

    Zircon U-Pb Geochronological Analyses ............................................................................................ 24

    Cathodoluminescence Imaging ......................................................................................................... 24

    Zircon REE Concentrations and U-Pb Concordia ........................................................................... 25

    Age Spectra ....................................................................................................................................... 27

    LiBO2 Glass Analyses .......................................................................................................................... 28

    Standard Analyses ............................................................................................................................. 28

    Sample Analyses ................................................................................................................................ 30

    Volume Strain and Element Mass Flux ............................................................................................. 31

    V. DISCUSSION ...................................................................................................................................... 34

    Do the Results Indicate Soils Formed Solely by Chemical Weathering of Underlying

    Bedrock? .............................................................................................................................................. 34

    Percent Insoluble Residue, Chemical Index of Alteration (CIA), XRD, and Grain Size and

    Shape ................................................................................................................................................. 34

    Age Distributions and K-S Tests ....................................................................................................... 36

    Deconvolution of Age Comp