Prehistoric Mining at the Great Orme
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PREHISTORIC MINING AT THE GREAT ORME Criteria for the identification of early mining C. Andrew Lewis M.Phil University of Wales – Bangor Agricultural and Forest Sciences September 1996 What then? Shall we sit idly down and say "The night hath come; it is no longer day"? The night hath not yet come; we are not quite Cut off from labour by the failing light; Something remains for us to do or dare . And as the evening twilight fades away, The sky is filled with stars, invisible by day. H.W.Longfellow SUMMARY This study describes and discusses the criteria for the identification of prehistoric or early mining on the Great Orme. Particular emphasis is placed on the geological conditions of the ore deposit and how this has governed the scale and morphology of the extensive workings now recognised at the site. This was achieved by underground and surface surveys of the workings together with precise recording of geological formations through the same areas. The principal routes through the 18-19th century workings were surveyed, concentrating on localities where evidence for early phases of mining existed. Geological recording took the form of logging individual rock strata and associated mineralisation from surface exposures to the deepest sections of the mine where early mining could be identified. The artefacts and features of the prehistoric workings were also investigated, by a review of all existing historical and archaeological documentation relating to the site supplemented by evidence obtained directly through this study. From this it was possible to distinguish differences in mining artefacts and features between the prehistoric period and the 18-19th centuries. Evidence for prehistoric mining from recognised sites throughout the British Isles, Ireland, Europe and the Near East has also been reviewed and comparisons made with similar evidence from the Great Orme mine workings. The limited evidence for mineral processing and complete lack of evidence for copper smelting on the Great Orme as well as the local area has also been discussed and possible sites for these operations are suggested. It is calculated that quantities of smelted copper metal in excess of 200 tonnes could have been mined from the Great Orme, suggesting this site may have been a significant contributor to metal production during the Bronze Age period in the British Isles. CONTENTS Page 1.0 INTRODUCTION 1 1.1 General Background 1 1.2 Purpose of the Study 1 1.3 Summary of Objectives 3 2. LITERATURE REVIEW 5 2.1 Introduction 5 2.2 Prehistoric Mining in Europe to Middle East 10 2.2.1 Spain 10 2.2.2 France 11 Bouche Payrol 12 Cabrieres 12 Seronais 13 2.2.3 Austria 14 2.2.4 Balkans Rudna Glava 15 Aibunar 15 2.2.5 Turkey 17 2.2.6 Near East 18 Timna 18 Northern Oman 19 2.2.7 India 20 2.3 Prehistoric Mining in Great Britain and Ireland 21 2.3.1 Ireland 21 Mount Gabriel 23 Ross Island 25 2.3.2 Great Britain 26 Cwmystwyth - Copa Hill 26 Nantyreira 28 Other Mid Wales Sites 29 Parys Mountain 29 Alderley Edge 30 2.4 Summary and Discussion 31 2.5 Historic Background to Mining at the Great Orme 35 2.5.1General 35 2.5.2 Roman Period 35 2.5.3 Post Roman Period 37 2.5.4 Elizabethan Period 38 2.5.5 18-19th Century Period 38 2.6 History of Archaeological Evidence at the Great Orme Mines 39 2.6.1 19th Century Evidence 39 2.6.2 Evidence Earlier this Century 42 2.7 History of Exploration and Recent Study 42 3. GEOLOGICAL BACKGROUND 48 3.1 Introduction 48 3.2 Historical Review 48 3.3 General Setting and Structure 51 3.4 Study Methods and Aims 53 3.4.1 Introduction 53 3.4.2 Survey Methods 54 3.4.3 Geological Surveys 60 3.5 Results and Interpretations 61 3.5.1 General 61 3.5.2 Local Structure 68 3.5.3 Mineralisation 70 Dolomitisation and Structural Control 70 Dolomitisation and Lithological Control 72 Ore Mineralogy 73 3.5.4 Lithology Alteration 78 Dolomite- Dolomitised Limestone 78 Mudstone 80 3.5.5 Superficial Deposits and Surface Development 81 3.6 Summary and Discussion 84 4. EVIDENCE FOR PREHISTORIC MINING 87 4.1 Introduction 87 4.2 Description of the Mine Workings 87 4.2.1 Introduction 87 4.2.2 Chronology of Discovery 88 4.2.3 Surface Workings 94 Introduction 94 Opencast 95 Southern Entrances 98 4.2.4 Underground Workings 101 Introduction 101 Form and Extent 102 Spoil and Associated Deposits 111 Calcite Speleothems 113 4.3 Artefacts 114 4.3.1 Stone Tools 114 Introduction 114 Classification 118 Distribution and Use 120 4.3.2 Bone Tools 121 Introduction 121 Preservation 121 Species and Anatomical Distribution 125 Distribution and Classification 128 4.3.3 Metal Tools 130 General 130 Analyses 133 4.3.4 Wooden Tools 134 4.3.5 Pottery 135 4.3.6 Lighting 136 4.4 Processing and Smelting 140 4.4.1 Introduction 140 4.4.2 Historical Evidence 140 Ffynnon Galchog 141 Ffynnon Rhufeinig 141 Ffynnon Gaseg 143 Ffynnon Tyn-y-pwll 143 4.4.3 Archaeological Evidence 144 4.4.4 Discussion and Summary 147 Processing 147 Smelting 149 Summary 150 4.4.5 Estimated Ore and Copper Production 150 Opencast 151 Underground Workings 151 5. DATING AND SAMPLE MATERIAL 152 5.1 Introduction 152 5.2 Sample Material and Radiocarbon Techniques 154 5.2.1 General 154 5.2.2 Results and Interpretations 155 5.3 Sample Material and Uranium Series Techniques 156 6. GENERAL SUMMARY - INTERPRETATION 159 6.1 Introduction 159 6.2 Summarised Evidence for Early Mining 159 6.2.1 Literature Review - Evidence for Prehistoric Mining 159 6.2.2 Geological Background 160 6.2.3 Evidence for Prehistoric Mining 161 6.2.4 Processing and Smelting 166 6.3 Chronological Development of Early Mining 167 7. CONCLUSIONS 170 REFERENCES 172 LIST OF PLATES page 1. Topographic setting of the Great Orme mines. Inside cover 2. Opencast workings during excavation in 1991. 45 3. Opencast workings and Great Orme Mines visitor centre. 45 4. Southern entrances and trench workings during excavation in 1991. 46 5. Southern entrances, trench workings and tourist walkways in 1996. 46 6. East face of opencast. 47 7. Soil horizon indicating boundary between recent and older spoil material. 47 8. Partly oxidised chalcopyrite stringer vein. 75 9. Malachite infilled joints in dolomite. 75 10. Prehistoric working at location 7c, north-west corner of opencast. 97 11. Underground prehistoric working at location 21. 97 12. Prehistoric working with stone hammer and calcite cemented spoil. 104 13. Part of large stope at location 18. 104 14. Cache of stone hammers located in vein E6-7. 115 15. Selection of stone tools. 115 16. Selection of prehistoric mining tools. 122 17. Markings made by bone tools in rotted dolomite. 122 18. 'Stone lamp' found in mine workings in late 1800's. 138 19. Earthenware vessel found in workings off Owens shaft. 138 20. Calcite flowstone covering floor of prehistoric passage. 145 21. Sequences of dolomitic silts, sands and gravels at Ffynnon Galchog site. 145 LIST OF FIGURES Page 1. Prehistoric mines of Europe 9 2. Prehistoric mines of Great Britain and Ireland 22 3. Radiocarbon chronology of prehistoric mines of Great Britain and Ireland 24 24 4. Great Ormes Head and location of mines in the Pyllau valley 36 5. Mine workings of the Pyllau valley 36 6. Geology of the Great Ormes Head (after Morton 1898) 49 7. Geology of Great Ormes Head 50 8. Underground survey - Level 1 56 9. Underground survey - Level 2 & 3 57 10. Underground survey - Level 4 58 11. Underground survey - Section A & B 59 12. Lithological succession - Opencast to Large stope 62 13. Lithological succession - Owens shaft 63 14. Lithological succession - Roman shaft 64 15. Geological succession - Section B 65 16. Lithological succession - Opencast to Roman shaft 66 17 Geological plan of Pyllau valley 67 18. Section through Opencast to Large stope 69 19. Extent of workings in Pyllau valley 91 20. 3D view of workings around Vivians shaft 92 21. 3D view of workings to NE of Vivians shaft 93 22. Section through mineralised fractures 93 23. Southern entrances and infilled trench veins 99 24. Plan - Location 21 107 25. Elevation - Location 21 108 26. Sections - Location 21 109 27. Diagrammatic view contrasting 18-19th century and prehistoric workings 110 28. Location of field monuments on the Great Ormes Head 142 29. Stone objects (after Dutton & Fasham 1994) 116 30. Stone objects (after Dutton & Fasham 1994) 117 31. Animal bone objects (after Dutton & Fasham 1994) 123 32. Copper alloy and animal bone objects (after Dutton & Fasham 1994) 124 33. Radiocarbon chronology of the Great Orme mines 153 LIST OF TABLES Page 1. Summary of radiocarbon dates for the Great Orme mines 89 2. Trace element analyses of samples from the Great Orme mines 131 3. Elemental analyses of metal samples from the Great Orme mines 131 4. Summary of Uranium Series dates for the Great Orme mines 157 5. Comparisons between Prehistoric and 18-19th Century 162 Evidence-Artefacts 6. Comparisons between Prehistoric and 18-19th Century 163 Evidence-Mining Features 7. Comparisons between Prehistoric and 18-19th Century 164 Evidence-Mining Features 8. Comparisons between Prehistoric and 18-19th Century Evidence-Spoil 165 ACKNOWLEDGEMENTS This study is the result of several years working both on surface and underground at the Great Orme mines, and could not have been completed without the assistance of the staff of Great Orme Mines Ltd and members of the Great Orme Exploration Society.