Chlorine in ground water : stable isotope distribution Item Type Dissertation-Reproduction (electronic); text Authors Kaufmann, Ronald Steven. Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 29/09/2021 13:00:23 Link to Item http://hdl.handle.net/10150/191084 CHLORINE IN GROUND WATER: STABLE ISOTOPE DISTRIBUTION by Ronald Steven Kaufmann 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 1984 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE As members of the Final Examination Committee, we certify that we have read the dissertation prepared by Ronald Steven Kaufmann entitled Chlorine in Ground Water: Stable Isotope Distribution and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Doctor of Philosophy ) rt (-6 L Date Date 1) mck. Date Of iet_cb-N-A Ct&4-- Date `.-3 , Date Final approval and acceptance of this dissertation is contingent upon the candidate's submission of the final copy 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. Dissertation Director Date 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 acknow- ledgment 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 judgment the proposed use of the material is in the inte- rests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED: DEDICATION This dissertation is dedicated to the memory'of my first teachers, my parents, Edgar J. Kaufmann and Ruth A. Kaufmann Rock. He ought to look with his own eyes into the book of nature and become able to understand it.— The knowledge of nature as it is - not as we imagine it to be - constitutes true philosophy. Paracelsus It is not your duty to finish the work but neither are you at liberty to neglect beginning it. - Pirke Abbot ACKNOWLEDGMENT Foremost, I thank the members of my dissertation committee, all of whom provided support, encouragement and ideas throughout this project. They are Austin Long, Stanley Davis, Victor Baker, Harold Bentley, Eugene Simpson and Chris Eastoe. I'm especially indebted to Dr. Long, who acted as committee director and Dr. Bentley, whose idea it was to look for chlorine isotope variation in the first place. A dissertation is not simply the work of one person, but rather the sum total of all one has learned, combined with the efforts of many other people. The following are just a few of my many teachers and helpers. teachers have been many in number. Samuel Upchurch of the University of South Florida in Tampa was the director of my Masters Thesis committee. He first led me to the machinery of science and showed me the importance of precision in analytical work, something that has a critical place in the present work. Robert Agatston of ARCO Oil and Gas, my uncle was not only instrumental in the acquisition of samples, he also first set my feet on the path of Geology that has led me here. Fred Phillips, Donald Graf, Alfred Truesdell, Tom Hoering and June Fabryka-Martin contributed samples and ideas iv through discussions which have affected this work. One teacher who should not go unmentioned is my daughter, Rachel. Born while I was writing the dissertation, she taught me that each day is new and not to be discouraged about the little travails of writing. Those who contributed to this project through their own labor are legion. Geof Thyne and Richard Forester (ARCO), William Kaiser (Texas Bureau of Economic Geology), Janet Schaller, Tom Casadeval (USGS Menlo Park) and Scripts Institute for Oceanographic Studies all contributed samples. Dave Stienke, Dave Rivera and Robert Butcher maintained the equipment used in the laboratory. Robert Nyberg provided the word processor on which this dissertation was written. Dr. Song Lin Cheng, office mate and friend, provided me with a working version of the WATEQF computer program. The list of teachers and contributors is almost endless. There is one person that I will single out for effort above and beyond what was required, my wife Barbara. With all the help I've received from others, it was her love and support that made this work possible. Parts of this work were funded under the U.S. Nuclear Regulatory Commission contract NRC-04-78-272, Battelle-OWI contract E512-04900, and by ARCO Oil and Gas Co. TABLE OF CONTENTS Page LIST OF ILLUSTRATIONS viii LIST OF TABLES x ABSTRACT xi INTRODUCTION 1 General Approach 1 Specific Approach 2 CHLORINE CHEMISTRY, GEOCHEMISTRY AND ISOTOPE CHEMISTRY 5 Chlorine Chemistry 5 Chlorine Geochemistry 9 The Chlorine Cycle 9 Chlorine in Ground Water 16 Ion Filtration 18 Chlorine Isotope Chemistry 27 Historical Perspective 27 Fractionation of Chlorine Isotopes 33 Summary 51 SAMPLE SELECTION AND ANALYTIC TECHNIQUES 54 Sample Selection 54 Selection of Analytic Techniques 56 Methyl Chloride Gas Preparation 57 Precision and Standardization 60 DISTRIBUTION OF CHLORINE ISOTOPES IN GROUND WATER ... 67 CHLORINE ISOTOPE VARIATION BY DIFFUSION IN GROUND WATER 74 Theoretical Chlorine Distributions 74 Desaulniers Samples 78 Milk River Aquifer Samples 81 Texas-Louisiana Samples 91 CHLORINE STABLE ISOTOPE COMPOSITION AS A TRACER 101 Ground-Water Chloride Sources 102 Chlorine Isotope Tracer Studies 105 Vi vii TABLE OF CONTENTS -- Continued Page CHLORINE ISOTOPE RESEARCH: PAST, PRESENT AND FUTURE 109 The Past 109 The Present 111 The Future 114 APPENDIX I. SOLUTE CONCENTRATION AND EQUILIBRIUM 117 APPENDIX II. BOUNDARY EQUATION DERIVATION 122 APPENDIX III. SAMPLE LOCATIONS 125 LIST OF REFERENCES 128 LIST OF ILLUSTRATIONS Figure Page 1. Stability of chlorine at standard pressure and 25 °C 7 2. The chlorine cycle of the crust 15 3. Osmosis and reverse osmosis experiments 19 4. Ion exclusion by semipermeable clay layers 22 5. Water movement in a basin 24 6. Counter-current thermogravitational effect 38 7. Counter-current electromigration experiment 40 8. Counter-current boundary theory - isotope distribution in an aquifer 43 9. Isotope variation and concentration ratio - according to counter-current boundary theory . 48 10. Isotope variation and length of diffusion path - simple diffusion 47 11. Isotope variation and length of diffusion path - counter-current column theory 50 12. Reaction vessel 59 13. Resultant chlorine isotope distributions as a function of aquifer depth 77 14. Desaulniers samples - depth .vs. 6 37C1 80 15. Milk River aquifer site map 83 16. Milk River aquifer Na and Cl concentration plot •. 87 17. Dual filtration interpretation of the Milk River aquifer data 90 viii ix LIST OF ILLUSTRATIONS -- Continued Figure Page 18. Cl concentration .vs. depth, Texas-Louisiana samples 92 19. 637C1 .vs. depth, Texas-Louisiana samples ... 96 20. 6 37C1 .vs. chloride concentration, Frio samples 97 LIST OF TABLES Table Page 1. Chlorine concentration in crustal materials 10 2. Chlorine minerals, a partial list 11 3. Summary of chlorine isotope studies 28 4. Chlorine isotope equilibrium calculations 31 5. Results of chlorine equilibrium experiment 36 6. Fragmentation pattern of CH3C1 + in mass spectrometer 61 7. Isotope measurements on halite from the Salina formation of Ohio 63 8. Isotope measurements of sea water and salt dome samples 65 9. Chlorine isotope measurements with respect to SMOC 68 10. Statistical significance of isotope measurements from SMOC 71 11. Results from the Milk River aquifer 88 12. Isotope measurements, chloride concentrations and depth of sample collection - Texas- Louisiana samples 94 13. Chlorine distribution in and around the Weeks Island and nearby Avery Island salt domes 106 ABSTRACT Eighty years of chlorine atomic weight measurements revealed no variation of the stable isotope ratio, 37 C1/ 35 C1 (with precision up to 1.0%.) in natural materials. This result is not surprising because chlorine occurs in rela- tively few compounds, has a strong affinity for the liquid phase, occurs mostly in the -1 oxidation state and organisms don't discriminate between chlorine isotopes. Chlorine isotopes have been found to fractionate in the laboratory during kinetic reactions, equilibrium between phases and diffusion. This dissertation examined chlorine isotope composi- tion of chloride from sea water halite, hydrothermal water samples and ground-water samples where chloride was likely moving by diffusion. The measurement method was mass spec- trometry of methyl chloride gas prepared by quantitative precipitation of AgC1 from solution, and reaction of the AgC1 with methyl iodide. The precision of the technique is 0.24%,. Results from sea water indicate that isotope ratios in sea water do not vary beyond measured uncertainty, thus sea water became the designated standard called SMOC (Stan- dard mean ocean chloride). xii Many of the samples measured in this study vary significantly, though most are within 1.0%, of SMOC. All halite and hydrothermal samples are heavier than SMOC. Ha- lite results may indicate isotope effects durina precipita- tion or time dependent variations of sea water. Hydro- thermal samples may indicate source differences and/or frac- tionation mechanisms.