University of Plymouth PEARL https://pearl.plymouth.ac.uk 04 University of Plymouth Research Theses 01 Research Theses Main Collection 1996 Human-environmental relations on Bodmin Moor during the Holocene Gearey, Benjamin Richard http://hdl.handle.net/10026.1/511 University of Plymouth All content in PEARL is protected by copyright law. Author manuscripts are made available in accordance with publisher policies. Please cite only the published version using the details provided on the item record or document. In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be sought from the publisher or author. HUMAN-ENVIRONMENT RELATIONS ON BODMIN MOOR DURING THE HOLOCENE By Benjamin Richard Gearey A thesis submitted to the University of Plymouth in fulfilment of the degree of DOCTOR OF PHILOSOPHY Department of Geographical Sciences Faculty of Science Febniaiy 1996 This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without the author's prior written consent. I LIBRARY STORE REFERENCE ONLY UNIVERSITY OF PLYMOUTH PLYMOUTH LIBRARY LIBRARY STORE REFERfiMCB ONLY J 90 0277953 3 Abstract . Human-Environment Relations on Bodmin Moor During the Holocene by Benjamin R.Gearey This thesis describes palaeoenvironmental investigations on Bodmin Moor aimed at determining the timing, nature and extent of human induced environmental change on the moor. Pollen, charcoal and loss-on-ignition investigations were carried out at two main areas with chronological control provided by radiocarbon dating. The first area investigated was Rough Tor where five sequences were examined. Palynological analysis of these sequences demonstrated that the early vegetation cover of the moors was dense hazel scrub with oak and birch as components of the local woodland. Clearance of this woodland began in the Neolithic and led to the spread of grassland and expansion of alder onto the damper soils of the upland slopes. Intensified clearance marks the Bronze Age, with the almost complete destruction of local tree and shrub cover. There is no evidence for cultivation and landuse was mainly pastoral. A reduction in anthropogenic activity at some point in the third millennium BP resulted in the expansion of trees and shrubs, although some form of activity probably continued nearby. Renewed clearance activity in the Iron Age/Romano-British period points to human interest in the higher moorland in this period. The development of meadow at Rough Tor North suggests continuing pastoral activity into the historical period. The medieval settlement and cultivation of the Rough Tor moors is evident in the demise of meadow, appearance of cereal pollen and spread of acid grassland. The second area investigated was the East Moor. Four sequences were examined along a transect from the higher slopes of the East Moor plateau to the valley bottom at Tresellern Marsh. Sediment accumulation began at different times at each location and it is suggested that late peat accumulation at one site was due to removal of earlier sediments through early tin streaming activity. Early Holocene vegetation cover on the high slopes was dense hazel with oak and perhaps some elm present locally. The valley was dominated by hazel and probably oak on the valley sides with alder spreading later onto the mire areas. Clearance in the Neolithic resulted in the spread of alder on the higher slopes and birch on the mires. Further clearance in the Bronze Age resulted in the demise of most of the tree and shrub cover and the spread of grass and heathland. Clearance intensified in the Romano-British period. Landuse was pastoral, although limited cultivation in Tresellern valley was possible. Grazing activity continued on the moor, with some cultivation near to Watery Marsh. Intensified activity in the medieval period was apparent in the form of increases in pastoral indicators in the pollen record and the presence of arable land indicated through the record of cereal pollen. The implications of the palaeoenvironmental data for the earliest settlement and human activity on the moor are considered and comparisons and contrasts between Bodmin Moor and other uplands in south-west England and the British Isles are drawn. The evidence for activity in the Neolithic and Bronze Age fits in with current theories of settlement on Bodmin Moor. The intensification of clearance and farming activity in the Romano-British period suggests that the scope and intensity of human interest in the moor did not decline at this time as has been interpreted from the archaeological record. Contents Page Chapter One Palaeoecological Study on the Uplands of South-West England 1.1 Introduction 1 1.2 South-west England: physical environment 2 1.3 Palaeoenvironmental study on the uplands of south-west England 2 Exmoor 3 West Penwith 6 Camm enellis 7 Hensbarrow 1 Dartmoor 1 1.4 Palaeoenvironmental investigation in the south-west 13 1.5 Bodmin Moor 15 Climate 18 Geology & geomorphology 18 Soils & vegetation 19 1.6 Settlement on Bodmin Moor: a summary 21 1.7 Palaeoenvironmental evidence from Bodmin Moor 29 Long profile studies 29 Palaeoenvironmental studies on archaeological sites 35 1.8 Palaeoenvironmental investigation on Bodmin Moor: summary 41 1.9 Human-environment relations on Bodmin Moor during the Holocene: research aims 43 i) Further elucidation of the general vegetational pattern 43 ii) Timing and extent of human impacts 43 Integration of the palaeoecological and archaeological records 44 iv) Landuse patterns 44 1.10 Summary 45 Chapter Two Palaeoecological Techniques - Theoretical and Practical Considerations and a Research Strategy for Palaeoenvironmental Investigations on Bodmin Moor 2.1 Introduction 47 2.2 Philosophical approaches and palaeoecology 47 2.3 Synthesis: a research strategy for palaeoenvironmental investigation on Bodmin Moor 50 Sampling sites and pollen taphonomic considerations 50 Sampling sites and research aims 52 2.4 Site selection 53 Sites considered and rejected: Withey Brook Valley 54 Trewortha Marsh 55 Redmoor Marsh 55 East Moor co-axial field system 55 Stannon-Louden area 55 Page Sampling sites selected: Rough Tor 55 East Moor 56 2.5 Techniques 56 Pollen analysis and the identification of human impact 56 Survey & sampling 57 Stratigraphic description and sub-sampling 58 Pollen extraction, identification and counting 58 Data presentation and analysis 60 Charcoal analysis 61 Loss-on-ignition 64 Magnetic susceptibility 66 Chronological control - radiocarbon dating 67 2.6 Summary 70 Chapter Three Archaeology and Prehistoric Activity in the Rough Tor Area: Implications for Palaeoenvironmental Study 3.1 Introduction 72 3.2 The Rough Tor area: general characteristics 74 3.3 Neolithic settlement on Bodmin Moor? The Rough Tor enclosure and the Louden long caim 74 The Rough Tor enclosure 75 The Louden long caim 81 3.4 Field systems on Rough Tor and beyond. Bronze Age pastoralism? 82 Rough Tor north & south 82 Louden Hill 87 Stannon Down & Stannon south 87 Butterstor & Garrow 89 Medieval and later activity in the Rough Tor area 89 3.5 Synthesis: archaeological evidence and human impact in the Rough Tor area 92 3.8 A tentative model of human impact and environmental change in the Rough Tor area: the palynological record 99 The Mesolithic 102 The Neolithic 103 Bronze Age 104 Medieval settlement 106 The charcoal record 106 3.9 Summary 107 Chapter Four Palaeoenvironmental Investigations at Rough Tor Part I- Rough Tor Marsh 4.1 Introduction 109 4.2 Rough Tor Marsh 109 CP Page 4.3 Methods 112 4.4 Results 112 Survey 112 LOI 116 Pollen analysis 116 4.5 Discussion: interpretation of the Rough Tor Marsh pollen diagram 116 4.6 Interpretation of the charcoal record 124 4.7 Human impact and environmental change at Rough Tor Marsh 125 The early vegetation 125 Evidence for clearance activity 126 Peat cutting at Rough Tor Marsh? 127 4.8 Summary 127 Part II - Rough Tor South 4.9 Introduction: the Rough Tor south sampling site 129 4.10 Methods Radiocarbon dates 131 4.11 Results 131 Survey 131 Lithostratigraphy 135 Magnetic susceptibility 135 Pollen analysis 135 4.12 Interpretation of the Rough Tor south pollen diagram 141 The early woodland cover 141 The spread of grassland and the A Inus rise 143 Later regeneration of trees and shrubs 146 4.13 Interpretation of the charcoal record 147 4.14 Discussion: anthropogenic impact and Holocene vegetational history at Rough Tor south Early vegetation change 149 Clearance of woodland and the spread of grassland 149 Intensification of activity 151 Reduction in anthropogenic activity 152 4.15 Summary 153 Part III - Rough Tor North: The Monoliths 4.17 Introduction: The Rough Tor monoliths 155 4.18 Methods 156 4.19 Results 156 Lithostratigraphy 156 LOI 161 Radiocarbon dates 165 Pollen analysis 165 4.20 Discussion: interpretation of the monolith pollen diagrams 169 Page Monolith A 169 Monolith B 176 Monolith C 183 4.21 Interpretation of the monolith charcoal records 189 4.22 Vegetation change at Rough Tor north 190 The early woodland cover 190 The demise of the local woodland 191 The development of grassland 192 4.23 Summary 194 Chapter Five Settlement History and Environmental Change: Integrating the Palaeoenvironmental and Archaeological Records at Rough Tor 5.1 Introduction 197 5.2 Interpretation of the DECORANA plots 198 Rough Tor south and Rough Tor north monoliths