Durham E-Theses
Total Page:16
File Type:pdf, Size:1020Kb
Durham E-Theses Flandrian sea-level changes in the Moray Firth area Haggart, B. A. How to cite: Haggart, B. A. (1982) Flandrian sea-level changes in the Moray Firth area, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/9365/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk FLANDRIAN SEA-LEVEL CHANGES IN THE MORAY FIRTH AREA by B.A. HAGGART The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. Thesis submitted for the degree of Doctor of Philosophy. University of Durham, Department of Geography. 5 AUG W82 February 1982 STATEMENT OF COPYRIGHT The copyright of this thesis rests with the author. No quotation from it should be published without prior written consent and information derived from it should be acknowledged. DECLARATION This thesis is the result of my own work. Data from other authors which are referred to in the thesis are acknowledged at the appropriate point in the text. 1 ABSTRACT The Moray Firth area is recognized as an area deficient in data relevant to sea-level change. This thesis attempts to provide a preliminary assessment of the restoration of sea-level following the last glaciation, particularly the last 10,000 years. The methodology used is essentially empirical and analytic, based upon stratigraphic description, micropalaeontological investig• ation and radiocarbon dating of sites in former tidal flat and lagoonal environments. Three sites at the head of the Beauly and Cromarty Firths, at Barnyards (NH 5247), Moniack (NH 5443) and Arcan Mains (NH 4954) provide stratigraphic and environmental evidence for the interpretation of sea-level change during the Flandrian Age. A preliminary chronological scheme of positive and negative tendencies of sea-level movement and a time-altitude graph is constructed using information from biostratigraphic and lithostratigraphic sea- level indicators and nine new radiocarbon dates. An attempt is made to assess the magnitude of error inherent at all stages of the analysis. Correlation is made with other areas of Scotland and Fennoscandia. A comparison is made between the differing methodologies employed in this thesis and other areas of Scotland where sequences of measured and named shorelines have been established. An isostatic curve for the inner Moray Firth is constructed using eustatic calibration of index point altitude. The results are compared to other published isostatic curves for Scotland. ACKNOWLEDGEMENTS I wish to express my sincere thanks to Dr. M.J.Tooley and Dr. J.D. Peacock, my joint supervisors, for their advice and criticism in all aspects of this work. Considerable help is also acknowledged from colleagues in the Department of Geography at Durham - Dr. I. Shennan for instruction in diatom identification and assistance with computing; Dr. P.A. GreatRex for providing plant macrofossil identif• ications; Mr. M.J. Davis and Miss F.M.J. Sutherland for advice and interesting discussion; Mrs. S. Everett, Miss H. Evans and Mrs. J. Dorril for help in the laboratory; Mr. Derek Hudspeth for photographically reducing the diagrams and Mrs. Margaret Bell for taking such care with the typing. I would also like to acknowledge the assistance in the field of Mr. R. Jowett, Mr. C.E. Dempsey, Mr. D. Bartlett, Miss A.M. Wilson and Miss J. Ogston. Access to land was granted by Mr. Forbes of Wellhouse, Mr. Peterkin of Barnyards, Mr. Munro of Tomich, Mrs. Gunn of Cabrich and Mr. Stirling of Arcan Mains. Finally I would like to thank Donald and Liz and my parents for their continual support and encouragement. in CONTENTS Page No, ABSTRACT i ACKNOWLEDGEMENTS ii LIST OF CONTENTS iii LIST OF FIGURES viii LIST OF TABLES x CHAPTER 1 : INTRODUCTION 1 1.1 Objectives 2 1.2 Methodology 3 1.3 Definitions 3 1.4 The Study area 8 1.5 Form of the thesis ' 11 CHAPTER 2 : GEOLOGICAL PERSPECTIVE ' - 13 2.1 Introduction ^3 2.2 Pre-Quaternary Geology ^ 14 2.3 The Quaternary Period 24 2.3.1 Quaternary events prior to the Devensian in Scotland 24 2.3.2 The Devensian ice maximum 28 2.3.3 Quaternary subsidence in the North Sea area. 34 2.3.4 Late Devensian ice limits and sea-levels 39 2.3.5 Conclusion 51 CHAPTER 3 : FLANDRIAN SEA-LEVEL CHANGES 53 3.1 Introduction 53 3.2 The Forth area 59 3.3 The Tay and east coast of Scotland 63 \ iv Page No. 3.4 The Ayrshire coast and Solway Firth 68 3.5 Other areas of Scotland 74 3.6 The Moray Firth area 75 3.7 A method of representing Flandrian coastal 78 sequences CHAPTER 4 : TECHNIQUES OF ANALYSIS 88 4.1 Introduction . ' 88 4.2 Levelling 88 4.3 Field Sampling 88 4.4 Stratigraphic analysis 90 4.5 Pollen analysis 92 4.6 Diatom analysis 97 4.7 Grain size analysis . 100 4.8 Radiocarbon dating 100 4.8.1 Variations in 14C/12C ratio ; 101 4.8.2 Isotopic fractionation 103 4.8.3 The Reservoir Effect 104 4.8.4 Contamination 105 4.8.5 Thickness of sample 106 4.8.6 Laboratory error 106 CHAPTER 5 : SITES INVESTIGATED 108 5.1 Barnyards 108 5.1.1 Barnyards stratigraphy 111 5.1.2 Barnyards 3B 118 5.1.2.1 BY3B Pollen H9 5.1.2.2 BY3B Diatoms 124 5.1.2.3 BY3B Particle size 129 5.1.2.4 BY3B l4C Dating 132 v Page No. 5.1.3 Barnyards 14B 132 5.1.3.1 BY14B Pollen 134 5.1.3.2 BY14B Diatoms 140 5.1.3.3 BY14B Particle si'ze and loss on ignition 143 5.1.3.4 BY14B 14C Dating 143 5.2 Moniack 144 5.2.1 Moniack stratigraphy 147 5.2.2 M29B 159 5.2.2.1 M29B Pollen 163 5.2.2.2 M29B Diatoms 167 5.2.3 M4B 172 5.2.3.1 M4B Diatoms 173 5.2.3.2 M4B 14C Dating 178 5.3 Arcan Mains 178 5.3.1 Arcan Mains 7 . 185 5.3.1.1 AM7 Pollen 188 5.3.1.2 AM7 Diatoms 192 5.3.1.3 AM7 Particle 'Size and Loss on 192 ignition 5.3.1.4 AM7 14C Dating 192 CHAPTER 6 : ENVIRONMENTAL EVIDENCE FOR SEA-LEVEL CHANGE 194 6.1 Introduction 194 6.2 Indicative range 197 6.3 Lithostratigraphic and biostratigraphic evidence of .199 sea-level change 6.4 Interpretation of data in terms of sea-level 201 movement Page No. 6.4.1 Barnyards 3B 202 6.4.2 Barnyards 14B 205 6.4.3 Barnyards - site interpretation 210 6.4.4 Moniack 29B 211 6.4.5 Moniack 4B 215 6.4.6 Moniack - site interpretation 216 6.4.7 Arcan Mains 7 218 6.4.8 Arcan Mains - site interpretation 221 6.5 Conclusion 222 CHAPTER 7 : FLANDRIAN SEA-LEVEL CHANGES IN THE INNER 223 ~ MORAY FIRTH AREA : 7.1 Barnyards 223 7.2 Moniack 227 7.3 Arcan Mains 229 7.4 Summary Chronology of Flandrian Sea-Level Change in 230 the Inner Moray Firth 7.5 A Time-Altitude Graph of Flandrian Sea-level changes 232 in the inner Moray Firth 7.5.1 Graph construction 238 7.6 Flandrian sea-level change in the inner Moray 241 Firth area CHAPTER 8 : INTER-REGIONAL CORRELATIONS 243 8.1 Introduction 243 8.2 s Statistical evaluation of 14C data ' 245 8.3 Comparison of sea-level changes in the inner Moray 259 Firth with other areas of Scotland 8.4 A preliminary isostatic curve for the Moray Firth area 269 8.5 Other correlations .276 vii Page No CHAPTER 9 : CONCLUSIONS 283 9.1 Flandrian coastal evolution in the Moray Firth 283 9.2 Proposals for further research 286 BIBLIOGRAPHY 289 APPENDIX I 314 APPENDIX II 324 APPENDIX III 339 APPENDIX IV 344 APPENDIX V 365 viii LIST OF FIGURES Facing Page W7 1.1 Location of study area 9 2.1 Major Permian to Mesozoic tectonic elements 15 of the North Sea 2.2 Distribution of Old Red Sandstone in the Moray 18 Firth area including the limits of the Mesozoic sedimentary basin 2.3 Interglacial and interstadial sites in Scotland 25 2.4 Central North Sea with location of boreholes 35 and radiocarbon dates 2.5 Late Devensian ice retreat stages and marine 43 limits of the inner Moray Firth 3.1 Published sea-level curves for Scotland 54 3.2 Provisional isobases for the 'Post-glacial 56 25-foot beach. ; 3.3 Provisional isobases for the Main Postglacial 56 Shoreline 3.4 Schematic section showing most commonly 81 encountered profile types in the Inner Moray Firth coastal area 3.5 Diagrammatic section of the Grangemouth - Airth 84 area showing main elements of the stratigraphy 3.6 Diagrammatic section of the Upper Forth Valley 84 5.1 Barnyards site map 109 5.2 Barnyards stratigraphy.