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MOLLUSK-SHELL RADIOCARBON AS A PALEOUPWELLING PROXY IN PERU by Kevin Bradley Jones A Dissertation Submitted to the Faculty of the DEPARTMENT OF GEOSCIENCES In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 2009 2 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE As members of the Dissertation Committee, we certify that we have read the dissertation prepared by Kevin Bradley Jones entitled Mollusk-Shell Radiocarbon as a Paleoupwelling Proxy in Peru and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Doctor of Philosophy Date: 10 April 2009 Warren Beck Date: 10 April 2009 Gregory Hodgins Date: 10 April 2009 Vance Holliday Date: 10 April 2009 Jonathan Patchett Date: 10 April 2009 Jay Quade Final approval and acceptance of this dissertation is contingent upon the candidate’s submission of the final copies of the dissertation to the Graduate College. I hereby certify that I have read this dissertation prepared under my direction and recommend that it be accepted as fulfilling the dissertation requirement. Date: 10 April 2009 Dissertation Director: Gregory Hodgins Date: 10 April 2009 Dissertation Director: Jay Quade 3 STATEMENT BY AUTHOR This dissertation has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED: Kevin Bradley Jones 4 ACKNOWLEDGMENTS This dissertation research would not have been possible without the generosity and cooperation of many people. I thank our Peruvian colleagues, Alejandro Chu, Ivan Ghezzi, and Ruth Shady Solís, as well as Dan Sandweiss and Fred Andrus for providing archaeological samples for analysis. Ellen Strong, Paul Greenhall, and the Invertebrate Zoology staff at the Smithsonian Institution loaned early 20th century scallops and allowed their sampling. I also thank Fred Andrus, Miguel Etayo, Greg Hodgins, Kim Grisham, David Reid, Kurt Rademaker, Dan Sandweiss, and María del Carmen Sandweiss for their hospitality, camaraderie, and companionship during the 2006 and 2007 field seasons in Peru. My dissertation committee, Warren Beck, Greg Hodgins, Vance Holliday, Jon Patchett, and Jay Quade, have provided suggestions and feedback over the course of my research, and their comments have improved this manuscript and the papers appended to it. Greg Hodgins, my dissertation advisor, has been particularly encouraging and I value his guidance. David Dettman of the Environmental Isotope Laboratory in the Geosciences Department and George Burr, Rich Cruz, Lori Hewitt, Tim Jull, Alex Leonard, and the entire staff of the NSF-Arizona AMS Facility were very helpful with sample preparation and analysis. My instructional colleagues, particularly Chuck Dugan and Kevin Bays at Kitt Peak National Observatory, and Shane Byrne and Priyanka Sharma of the Lunar and Planetary Laboratory have been wonderfully accommodating while I have put in long hours finishing this dissertation. Over the past six years, my friends and fellow graduate students in Tucson have enriched my life through socializing and science discussions over coffee and campfires. Thank you to Kevin Anchuktaitis, Toby Ault, Joan Blainey, Jessica Conroy, Maarten de Moor, Mat Devitt, Jesse Driscoll, Anna Felton, Nicole Flowers, Andy Frassetto, Christine Gans, Jerome Guynn, Dave Keeler, Lynnette Kleinsasser, Susan Mentzer, Andrea Philippoff, Amanda Reynolds, Jessica Rowland, Scott St. George, Tim Shanahan, Britt Starkovich, Aly Thibodeau, and many others. Finally, thank you to my parents, Bill and Brenda Jones, for their endless support and encouragement; to my granddad, Jim Clements, for prodding me to wrap up my dissertation (by saying “I’m not getting any younger!”) so that he can see me graduate in May; to Jerre Johnson, Professor Emeritus at the College of William & Mary, for sparking my interest in geological research nearly two decades ago; and to Andrea Philippoff for her constant love and understanding. Funding for this dissertation was provided by NSF grants OCE-0502542 and OCE-0446861, the NSF-IGERT Archaeological Sciences Program, ChevronTexaco, the Kartchner Caverns Scholarship Fund, the Institute for the Study of Planet Earth, the Archaeological Geology Division of the Geological Society of America, the Graduate and Professional Student Council of the University of Arizona, and the NSF-Arizona AMS Facility. 5 DEDICATION To my parents, Bill and Brenda, and my fiancée, Andrea: Thank you for your love and encouragement. 6 TABLE OF CONTENTS LIST OF TABLES.............................................................................................................. 8 LIST OF FIGURES ............................................................................................................ 9 ABSTRACT...................................................................................................................... 11 CHAPTER 1: INTRODUCTION..................................................................................... 13 1.1. Statement of the problem .................................................................................... 13 1.2. Dissertation format .............................................................................................. 16 CHAPTER 2: PRESENT STUDY ................................................................................... 20 2.1. Background .......................................................................................................... 20 2.1.1. Physiographic setting...................................................................................... 20 2.1.2. Holocene history of ENSO and El Niño events in Peru.................................. 21 2.1.3. Molluscan growth bands................................................................................. 25 2.2. Study sites and samples ....................................................................................... 26 2.3. Methods................................................................................................................. 27 2.4. Results ................................................................................................................... 29 2.5. Discussion ............................................................................................................. 30 2.5.1. Annual mean marine reservoir age................................................................. 30 2.5.2. Range in marine reservoir age ....................................................................... 34 2.5.3. Relationship between δ18O and 14C ................................................................ 37 2.6. Conclusions........................................................................................................... 39 REFERENCES ................................................................................................................. 41 APPENDIX A: SEASONAL VARIATIONS IN PERUVIAN MARINE RESERVOIR AGE FROM PRE-BOMB ARGOPECTEN PURPURATUS SHELL CARBONATE..... 54 A.1. Abstract................................................................................................................ 56 A.2. Introduction......................................................................................................... 56 A.3. Material and methods......................................................................................... 60 A.4. Reservoir correction calculations ...................................................................... 61 A.5. Results .................................................................................................................. 63 A.6. Discussion............................................................................................................. 64 A.7. Conclusions.......................................................................................................... 68 A.8. Addendum ........................................................................................................... 69 A.9. Acknowledgments ............................................................................................... 69 A.10. References.......................................................................................................... 69 APPENDIX B: UPWELLING SIGNALS IN RADIOCARBON FROM EARLY 20TH CENTURY PERUVIAN BAY SCALLOP (ARGOPECTEN PURPURATUS) SHELLS81 B.1. Abstract................................................................................................................ 82 B.2. Introduction ......................................................................................................... 83 B.2.1. Marine radiocarbon dating ............................................................................ 84 7 B.2.2. Previous work................................................................................................. 86 B.2.3. Physiographic setting ....................................................................................
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