University of North Dakota UND Scholarly Commons Theses and Dissertations Theses, Dissertations, and Senior Projects 2014 Landscape evolution and preservation of ice over one million years old quantified with cosmogenic nuclides 26Al, 10Be, and 21Ne, Ong Valley, Antarctica Theodore C. Bibby University of North Dakota Follow this and additional works at: https://commons.und.edu/theses Part of the Geology Commons Recommended Citation Bibby, Theodore C., "Landscape evolution and preservation of ice over one million years old quantified with cosmogenic nuclides 26Al, 10Be, and 21Ne, Ong Valley, Antarctica" (2014). Theses and Dissertations. 20. https://commons.und.edu/theses/20 This Dissertation is brought to you for free and open access by the Theses, Dissertations, and Senior Projects at UND Scholarly Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of UND Scholarly Commons. For more information, please contact [email protected]. LANDSCAPE EVOLUTION AND PRESERVATION OF ICE OVER ONE MILLION YEARS OLD QUANTIFIED WITH COSMOGENIC NUCLIDES 26AL, 10BE, AND 21NE, ONG VALLEY, ANTARCTICA by Theodore C. Bibby Bachelor of Science, Florida State University, 2009 A Dissertation Submitted to the Graduate Faculty of the University of North Dakota in partial fulfillment of the requirements for the degree of Doctor of Philosophy Grand Forks, North Dakota December 2014 Copyright 2014 Theodore C. Bibby ii This dissertation, submitted by Theodore C. Bibby in partial fulfillment of the requirements for the Degree of Doctor of Philosophy from the University of North Dakota, has been read by the Faculty Advisory Committee under whom the work has been done and is hereby approved. Jaakko Putkonen ______________________________ Ronald Matheney ______________________________ Gregory Vandeberg ______________________________ Alena Kubátová ______________________________ Dongmei Wang This dissertation is being submitted by the appointed advisory committee as having met all of the requirements of the School of Graduate Studies at the University of North Dakota and is hereby approved. _________________________________ Dr. Wayne Swisher Dean of the School of Graduate Studies _________________________________ Date iii PERMISSION Title Landscape Evolution and Preservation of Ice Over One Million Years Old Quantified with Cosmogenic Nuclides 26Al, 10Be, and 21Ne, Ong Valley, Antarctica Department Harold Hamm School of Geology and Geological Engineering Degree Doctor of Philosophy In presenting this dissertation in partial fulfillment of the requirements for a graduate degree from the University of North Dakota, I agree that the library of this University shall make it freely available for inspection. I further agree that permission for extensive copying for scholarly purposes may be granted by the professor who supervised my dissertation work or, in his absence, by the Chairperson of the department or the dean of the School of Graduate Studies. It is understood that any copying or publication or other use of this dissertation or part thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of North Dakota in any scholarly use which may be made of any material in my dissertation. Theodore C. Bibby 10/10/2014 iv TABLE OF CONTENTS Page LIST OF FIGURES ...............................................................................................................vii LIST OF TABLES .................................................................................................................ix ACKNOWLEDGEMENTS ...................................................................................................x ABSTRACT ...........................................................................................................................xii CHAPTER I. INTRODUCTION ............................................................................................1 Background ..............................................................................................2 II. FIELD AREA ...................................................................................................7 Location ...................................................................................................7 Geology ....................................................................................................8 III. METHODS ..........................................................................................................12 Cosmogenic Nuclides Background ..........................................................12 Field Methods ..........................................................................................16 Lab Methods ............................................................................................19 Nuclide Concentration Analysis ..............................................................20 Error Distribution .....................................................................................25 IV. RESULTS ............................................................................................................27 Youngest Drift .........................................................................................27 v Middle Drift .............................................................................................33 Oldest Drift ..............................................................................................39 V. DISCUSSION ......................................................................................................46 Isotope Concentrations of Debris within the Ice......................................46 Sublimation Rates ....................................................................................49 Erosion Rates ...........................................................................................50 VI. CONCLUSIONS..................................................................................................52 APPENDIX ......................................................................................................................67 REFERENCES ................................................................................................................102 vi LIST OF FIGURES Figure Page 1. Ong Valley Satellite Image ............................................................................................... 5 2. Panorama of Ong Valley. ................................................................................................... 6 3. Geologic Map of Ong Valley ........................................................................................... 11 4. Conceptual Schematic Representation of the Bombardment of Earth by Cosmic Rays.................................................................................................................................. 14 5. Accumulation of Cosmogenic Nuclides over time with steady State Erosion ................ 15 6. Cartoon Depicting the Formation and Accumulation of Sublimation Till from Englacial Debris Followed by Sampling ......................................................................... 15 7. Sample Sites and Topographic Shielding ........................................................................ 18 8. Typical Field Sampling Procedure of Bulk Regolith ....................................................... 19 9. Youngest Drift: Concentration vs. Effective Shielding Mass of Measured Nuclides. .... 30 10. Youngest Drift: Plot of 10Be vs. (26Al/10Be) .................................................................... 31 11. Youngest Drift: Sublimation based Monte Carlo Simulation .......................................... 32 12. Youngest Drift: Erosion based Monte Carlo Simulation. ................................................ 33 13. Middle Drift: Concentration vs. Effective Shielding Mass of Measured Nuclides ......... 37 14. Middle Drift: Sublimation based Monte Carlo Simulation.............................................. 38 15. Middle Drift: Erosion based Monte Carlo Simulation ..................................................... 39 16. Oldest Drift: Concentration vs. Effective Shielding Mass of Measured Nuclides. ......... 42 17. Oldest Drift: Plot of 10Be vs. (26Al/10Be) ......................................................................... 43 vii 18. Oldest Drift: Sublimation based Monte Carlo Simulation ............................................... 44 19. Oldest Drift: Erosion based Monte Carlo Simulation. ..................................................... 45 viii LIST OF TABLES Table Page 1. Depth, Density, Effective Shielding Mass and Isotope Data ........................................... 57 2. Nuclide Production Values at Each Sample Site ............................................................. 61 3. Cosmogenic 21Ne Samples in Till Clast Separation Model Results ................................ 62 4. Calculated 21Ne Exposure Ages ..................................................................................... 645 5. Calculated 26Al, 10Be Exposure Ages .............................................................................. 66 ix ACKNOWLEDGEMENTS I wish to express my sincere gratitude to my advisor, Dr. Jaakko Putkonen, who has provided guidance, inspiration, support, and a great example to follow throughout my academic career. I cannot thank Dr. Putkonen enough for his patience as I worked my way through