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Qt74f9q261 Nosplash 864999B UNIVERSITY OF CALIFORNIA RIVERSIDE Intermediate and Vacillating Redox in Ancient Marine Settings and their Biological Implications A Dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Geological Sciences by Dalton Shane Hardisty August 2016 Dissertation Committee: Dr. Timothy W. Lyons, Chairperson Dr. Gordon D. Love Dr. Andrey Bekker Copyright by Dalton Shane Hardisty 2016 The Dissertation of Dalton Shane Hardisty is approved: Committee Chairperson University of California, Riverside ACKNOWLEDGMENTS The last five years really have been an adventure. A small town Hoosier doesn’t usually get the opportunities I’ve enjoyed, with the pursuit of my interests most limited by my own ability. I have a lot of people to thank for that. This spans from the mentorship, collaboration, and training I’ve received, to the friends and family who’ve provided me the support and motivation to pursue my goals and have made it easy along the way. In many cases the distinction between these have blurred, which is what I’m most lucky for. I want to first thank those I’ve been lucky enough to call my mentors and friends. Tim, you are the hardest working person I know and I don’t think I’m currently capable of grasping the time, energy, resources, and patience you’ve given me along the way. It’s really a debt that you’ll never receive full payment for, regardless of what I give back. I’m beyond grateful and respect the hell out of you. Gordon, despite that you are a golf foe, I consider you a close friend and respect you as a gentleman and a scholar. Thanks for everything. Zunli, I seriously couldn’t have done this without you. Thanks for keeping me afloat, putting your trust in me with your proxy, and for the good times along the way. Others I consider essential include Noah Planavsky, Steve Bates, Andrey Bekker, Jeremy Owens, and Natascha Riedinger. The list is long of folks I’ve gotten to work with and now consider, and even their families in in some cases, close friends. These include Robyn Dahl, Alex and Ashley Zumberge, Chris Reinhard, Lidya Tarhan, Konstantin Choumiline, Bridget Lee, Charles Diamond, Carina Lee, Stephanie Olson, Andy Robinson, Kevin Nguyen, Sarah Simpson, Davy Crockett, and Brett Holdaway. You are each awesome in your own way and it’s thanks to you that Riverside has become home to me. Thank you. iv Of course the bulk of the thanks goes to my family, particularly my Mom (Dee), Dad (Dale), brother (Dylan), Grandma and Papaw Hardisty, Grandma and Grandpa Orman, and more recently my fiancé (and favorite collaborator) Leanne. I’ve always been encouraged to pursue what I’m passionate about and you’ve continually steered me toward the right path, whether I knew it or not. I don’t take that for granted. Regardless of what anyone thinks of or gets from this dissertation, it really has been a lot of work and has involved sacrifices along the way too — particularly the experiences I’ve missed with you. Thank you for your inspiration, understanding, and unwavering support, the bleachers have never been empty. I dedicate this dissertation to you. v ABSTRACT OF THE DISSERTATION Intermediate and Vacillating Redox in Ancient Marine Settings and their Biological Implications by Dalton Shane Hardisty Doctor of Philosophy, Graduate Program in Geological Sciences University of California, Riverside, August 2016 Dr. Timothy W. Lyons, Chairperson The presence of marine oxygen is an essential precursor for faunal habitability, driving distribution in coastal systems today and linked to evolutionary patterns throughout the geologic past. In oxygen-deficient marine systems, the reducing capacity can be defined by the zonation of redox-sensitive elements (e.g. O, I, N, Mn, Fe, S, C), with their availability in the rock record in some cases linked to the water column redox state during deposition and subsequent burial processes. In this dissertation, I reconstruct paleoredox in environments defined by water column oxygen deficiency at biologically critical levels, specifically extreme low oxygen to mildly sulfidic, a redox window most representative of reducing systems today but largely underexplored in the geologic past. First, I present the initial surface ocean-specific Precambrian redox record, the location and period hosting the emergence of both oxygenic photosynthesis and multicellular life, evaluated through iodine-to-calcium-magnesium ratios in mostly shallow carbonate and supplemented through study of iodine retention during carbonate diagenesis. Oxygen became widespread in shallow marginal marine settings starting in the Paleoproterozoic, likely at levels iv necessary to support simple animals. The ensuing Proterozoic record was dynamic, with oxygen fluctuating at and below thresholds similar to waters within and directly overlying modern oxygen minimum zones and largely constrained to shallow settings, a condition particularly exacerbated during the middle Proterozoic. This is a new view of the Precambrian surface ocean and such variability and spatially restricted marine oxygen at critically low levels is hypothesized to explain the delayed emergence of animals until the Neoproterozoic. A second study defines natural variations in water column redox in the Baltic Sea over the Holocene, the world’s largest modern anthropogenically forced and spatially and temporally variable low-oxygen basin. An iron-manganese-molybdenum geochemical approach reveals distinct phases of large-scale anoxia during the Holocene, with the magnitude and frequency of anoxia increasing with increasing distance from the sill, but never beyond mild sulfide accumulation. This work specifically indicates that spatial and temporal variability in Baltic redox appears to have driven both long-term oxygen depletion and restrained the maximum reducing potential over the Holocene. v Table of Contents INTRODUCTION AND MOTIVATION ....................................................................... 1 REFERENCES ...................................................................................................................... 12 CHAPTER 1 .................................................................................................................... 15 An iodine record of Paleoproterozoic surface ocean oxygenation ................................ 15 ABSTRACT ........................................................................................................................... 16 INTRODUCTION ................................................................................................................. 16 MATERIALS AND METHODS ........................................................................................... 17 RESULTS AND DISCUSSION ............................................................................................ 20 CONCLUSION ...................................................................................................................... 27 REFERENCES CITED .......................................................................................................... 28 SUPPLEMENTAL MATERIALS ......................................................................................... 31 SUPPLEMENTARY REFERENCES ................................................................................... 42 CHAPTER 2 .................................................................................................................... 45 Iodine constraints on Proterozoic shallow ocean redox and their biological implications ....................................................................................................................................... 45 ABSTRACT ........................................................................................................................... 46 INTRODUCTION ................................................................................................................. 47 MATERIALS ......................................................................................................................... 50 RESULTS .............................................................................................................................. 51 DISCUSSION ........................................................................................................................ 55 METHODS ............................................................................................................................ 62 REFERENCES CITED .......................................................................................................... 64 SUPPLEMENTAL MATERIALS ......................................................................................... 69 SUPPLEMENTAL REFERENCES CITED ........................................................................ 132 CHAPTER 3 .................................................................................................................. 142 Insights from the FOAM site, Long Island Sound, U.S.A: Calibrating Fe and Mo geochemistry for sedimentary paleoredox determinations.......................................... 142 ABSTRACT ......................................................................................................................... 143 INTRODUCTION ............................................................................................................... 144 BACKGROUND ................................................................................................................. 145 METHODS .........................................................................................................................
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