Thesis, and Not to Quote Or Make a Copy of the Whole Or Any Substantial Part of It Without the Written Consent of the Author and of the University of Bath
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University of Bath PHD Radium, radon and inert gases in groundwaters and rocks as geochemical tracers. Lee, D. J. Award date: 1980 Awarding institution: University of Bath Link to publication Alternative formats If you require this document in an alternative format, please contact: [email protected] General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Download date: 10. Oct. 2021 60 8052379 5 TELEPEN X ill I lli II. UNIVERSITY OF BATH UNIVERSITY LIBRARY Author D.J,. LEE.............. (PhD . the sis ).___ Date . Î ? 80, Radium, Radon and Inert Gases in Groundwaters Title and Hocks as Geochemical Tracers. I undertake not to publish either the whole or any part of this thesis, and not to quote or make a copy of the whole or any substantial part of it without the written consent of the author and of the University of Bath. I further undertake to allow nobody else to use this thesis while it is issued to me. ProQuest Number: U311828 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest. ProQuest U311828 Published by ProQuest LLC(2015). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. Microform Edition © ProQuest LLC. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 î H uwr. .. n b' I 3-FEB198I Déclaration ID. J. Lee hereby declare that the contents of this thesis are substantially my own unaided work and 1 am the joint author of the published papers included in Appendix 5. The work was carried out whilst 1 was registered as a candidate for the Degree of Doctor of Philosophy at the University of Bath, D. J. LEE ABSTRACT Natural radioéléments and inert gases in solution in groundwaters nave been applied to problems of groundwater flow 4 and age measurement. The He content of groundwaters generally increases with age and in the Hunter Sandstone, Nottinghamshire, 4 the He contents of groundwaters have been linearly related to 14 4 C ages. In the Lincolnshire Limestone, the He contents of the groundwaters have been used to indicate mixing of recharge 4 water and interstitial water. In the other study areas, He and 40 Ar in groundwaters have been used as qualitative indicators of 4 age. The He contents of core samples have been related to the 4 He contents of the interstitial water and the formation depth. 4 He diffusion in confined and non-confined sedimentary structures has been discussed. The amounts of non-radiogenic inert gases dissolved in groundwaters have been used to estimate groundwater recharge temperatures. In the Hunter Sandstone, these have been related 14 to palaeoclimatic history by calibrating with the C ages. Estimated recharge temperatures have also been related to seasonal recharge, changes in the altitude of recharge and to variations in the hydrogen and oxygen isotopic ratios. 222 Variation of the Rn contents of groundwaters has been used as an indicator of aquifer variability. The relative importance of intergranular and fissure flow and the variation 222 in efficiency of Rn release into groundwaters has been 222 investigated. The fraction of Rn released from rocks has been 222 determined and the mechanisms by which Rn is released from (ii) sandstone, limestone and granite rock fragments has been 226 discussed. Variability of the Ra contents of groundwaters has been explained in terms of the relative importance of the recoil and etch mechanisms of solution and the solubility of 226 Ra salts in groundwaters. (iii) TABLE OF CONTENTS TITLE PAGE....................................................... (i) a b s t r a c t .............................•................ (ii) LIST OF FIGURES.................................................. (xi) LIST OF TABLES................................................... (xv) CHAPTER 1 INTRODUCTION........ ........................... 1 1 .1 . THE NATURE OF RADIOACTIVITY..................... 1 1.1 Introduction.................................. 1 1.2 Nuclear reactions............................. 2 1.3 Radioactive decay............................. 3 1.4 Radioactive decay processes................... 5 1.5 Radioactive series............................ 10 1.6 The determination of geological age........... 1 1 2 . THE GEOCHEMISTRY OF URANIUM AND THORIUM........ 15 2.1 The uranium and thorium content of igneous rocks 17 2.2 Uranium and thorium in sedimentary rocks..... 20 3. THE GEOCHEMISTRY OF RADIUM...................... 25 4. THE GEOCHEMISTRY OF RADON....................... 30 5. THE GEOCHEMISTRY OF THE INERT GASES ....... 33 5.1 Helium......................... .............. 35 5.2 Argon, 42 5.3 Neon, krypton and xenon.............................. 45 6. THE NATURE OF GROUNDWATER............... 50 6.1 The occurrence of groundwater........................ 50 6.2 Porosity............................................ 51 6.3 Groundwater boundaries............................... 51 6.4 Groundwater storage and movement.,.................... 53 6.5 Groundwater quality....................... 64 7. ISOTOPE TECHNIQUES IN HYDROLOGY........................ 67 (iv) 1.8. STABLE ISOTOPE TRACING............................. 69 1.9. TRITIUM............................................ 72 1.10. CARBON-14........ .................................. 76 1.11. U-234/U-238 TRACING................................ 86 1.12. RADON IN GROUNDWATERS.............................. 89 1.13. RADIUM IN GROUNDWATERS............................. 94 1.14. INERT GASES IN GROUNDWATERS......................... 96 1.14.1. Helium.................. 96 1.14.2. Radiogenic argon................................. 100 1.14.3. Neon, argon, krypton and xenon..................... 103 CHAPTER 2. EXPERIMENTAL METHODS...... 105 2.1. GROUNDWATER ANALYSIS................................ 105 226 222 2.1.1. Ra and Rn in groundwaters................... 105 2.1.1.1. Sample collection............... ;. 105 226 222 2.1.1.2. Determination of Ra and Rn by 107 oC-scintillation counting ................. 222 2.1.1.3. Determination of Rn by X-spectrometry......... .113 222 226 2.1.1.4. Errors in the determination of Rn and Ra.... 114 2.1.2. Inert gases in groundwaters....................... 118 2.1.2.1. Sample collection............................... 118 2.1.2.2. Experimental technique................. 122 2.1.2.3. Calculation of the inert gas volumes............. 123 2.1.2.4. Calibration of tracer ratios and volumes.......... 127 2.1.2.5. Errors in the determination of inert gases...... 133 2.1.2.6. Determination of ^^Ar/^^Ar in groundwaters........ 139 2.2, ROCK ANALYSIS............ 140 2.2.1. Uranium content of rock samples.... ... ........... 140 2.2.2. Thorium content of rock samples.................... 141 222 2.2.3. Rn release from rocks.......................... 143 Cv) 2.2.3.1. Sample collection.............................. 143 2.2.3.2. Experimental.................................... 144 2.2.3.3. Errors.......................................... 145 2.2.4. Helium content of rock samples................... 145 2.2.4.1. Experimental..................... 145 2.2.4.2. Calculation.................................... 146 2.2.4.3. Errors......................................... 150 CHAPTER 3. RADON, RADIUM AND DISSOLVED INERT GASES IN 152 GROUNDWATERS FROM THE BUNTER SANDSTONE, ........... NOTTINGHAMSHIRE................................... 3.1. INTRODUCTION....................................... 152 3.2. RESULTS AND DISCUSSION............................. 154 3.2.1. Uranium and thorium contents of the Bunter 154 Sandstone........................................ 226 222 3.2.2. Ra and Rn contents................... 156 4 3.2.3. Radiogenic He contents........................... 161 3.2.4. Palaeoteraperatures of recharge derived from 170 inert gas contents............................... 3.3. CONCLUS IONS........................................ 174 CHAPTER 4. R.ADON, RADIUM AND DISSOLVED INERT GASES IN 176 GROUNDWATERS FROM THE SEDIMENTARY BASINS AROUND AVON, SOUTH WALES AND THE DERBYSHIRE DOME.......... 4.1. INTRODUCTION...................................... 176 4.2. RESULTS AND DISCUSSION............................. 180 222 226 4.2.1. Rn and Ra contents......................... 180 4 4.2.2. Radiogenic He contents...... 187 40 4.2.3. Radiogenic Ar contents.......................... 193 4.2.4. Recharge temperatures estimated from inert gas 194 contents......................................... (vi) 222 226 4 4.3. t emporal MONITORING OF Rn, Ra AND He 196 CONTENTS IN SOME GROUNDWATERS IN AVON, 4.4. INTERPRETATION