ALSF AGGREGATE EXTRACTION IN THE LOWER RIBBLE VALLEY Final Report Volume 1: Text Oxford Archaeology North Department of Geography February 2007 English Heritage NGR: SD 586306 Issue No: 2006-7/619 OA North Job No: L9518 Document Title: ALSF AGGREGATE EXTRACTION IN THE LOWER RIBBLE VALLEY Document Type: Final Report Client Name: English Heritage Issue Number: 2006-7/619 OA Job Number: L9518 National Grid Reference: SD 586306 Checked by: Jamie Quartermaine Signed……………………. Position: Project Manager Date: February 2007 Approved by: Rachel Newman Signed……………………. Position: Director Date: March 2007 Oxford Archaeology North © Oxford Archaeological Unit Ltd (2007) Storey Institute Janus House Meeting House Lane Osney Mead Lancaster Oxford LA1 1TF OX2 0EA t: (0044) 01524 848666 t: (0044) 01865 263800 f: (0044) 01524 848606 f: (0044) 01865 793496 w: www.oxfordarch.co.uk e: [email protected] Oxford Archaeological Unit Limited is a Registered Charity No: 285627 Disclaimer: This document has been prepared for the titled project or named part thereof and should not be relied upon or used for any other project without an independent check being carried out as to its suitability and prior written authority of Oxford Archaeology being obtained. Oxford Archaeology accepts no responsibility or liability for the consequences of this document being used for a purpose other than the purposes for which it was commissioned. Any person/party using or relying on the document for such other purposes agrees, and will by such use or reliance be taken to confirm their agreement to indemnify Oxford Archaeology for all loss or damage resulting therefrom. Oxford Archaeology accepts no responsibility or liability for this document to any party other than the person/party by whom it was commissioned. ALSF Aggregate Extraction and the Geoarchaeological Heritage of the Lower Ribble, Lancashire i VOLUME 1 CONTENTS CONTENTS ............................................................................................................................ I LIST OF TABLES ................................................................................................................. III ACKNOWLEDGEMENTS ....................................................................................................... V SUMMARY..........................................................................................................................VII 1 INTRODUCTION ..................................................................................................... 1 1.1 Aggregate Extraction Background ........................................................................ 1 1.2 Contract Background ............................................................................................ 2 1.3 The Ribble Valley study areas .............................................................................. 2 1.4 Aims of the Project ............................................................................................... 4 1.5 Objectives .............................................................................................................. 4 1.6 Structure of the Report .......................................................................................... 6 2 BACKGROUND ....................................................................................................... 7 2.1 Ribble Topography – Countryside Character Areas ............................................. 7 2.2 The Geology of the Ribble Basin .......................................................................... 8 2.3 Prehistoric Archaeology and Palaeoenvironment ............................................... 12 2.4 Romano-British Archaeology and Palaeoenvironment ....................................... 21 2.5 Early medieval Archaeology and Palaeoenvironment ........................................ 24 2.6 Medieval Archaeology ........................................................................................ 27 2.7 Post-medieval Archaeology of the Ribble Valley ............................................... 30 3 METHODOLOGY .................................................................................................. 33 3.1 Introduction ......................................................................................................... 33 3.2 Structural Overview of the GIS .......................................................................... 33 3.3 Characterising the Geological and Geomorphological Resource ....................... 34 3.4 Interrogation of Remotely Sensed Data .............................................................. 35 3.5 Fieldwork: Mapping, Drilling, Sampling ............................................................ 39 3.6 Outline of Approach to the Geomorphic Analysis .............................................. 40 3.7 Geochronology: Optically Stimulated Luminescence (OSL) and Radiocarbon Dating ............................................................................................ 41 3.8 Characterising the Natural Landscape as a Heritage Asset ................................. 52 3.9 Characterising the Archaeological Resource ...................................................... 53 3.10 Characterising the Palaeobotany of the Lower Ribble Valley ............................ 61 3.11 Assessing the Mineral Potential and Geomorphic Risk ...................................... 64 3.12 Enhancing an Understanding of the Archaeological Resource ........................... 77 3.13 Modelling Archaeological Potential ................................................................... 81 4 ASSESSMENT OF METHODS ................................................................................ 86 4.1 Introduction ......................................................................................................... 86 4.2 Assessment of Archaeological Data Capture ...................................................... 86 4.3 Assessment of Statistical Methods ...................................................................... 92 For the use of English Heritage © OA North and University of Liverpool February 2006 ii ALSF Aggregate Extraction and the Geoarchaeological Heritage of the Lower Ribble, Lancashire 4.4 Assessment of Geological and Geomorphic Techniques .................................... 93 4.5 Recommendations for Future Methods Looking at Aggregate Research ........... 95 5 THE LANDSCAPE: A HERITAGE RESOURCE ...................................................... 95 5.1 Glacial History of the Ribble Basin .................................................................... 96 5.2 Fluvial Geomorphology and Sedimentology .................................................... 101 5.3 Vegetation History of the Ribble Basin and an Assessment of the Palaeobotanic Potential of the Valley ............................................................... 125 5.4 Evolution of the Landcape: Synthesis and Needs for Future Research ............ 129 6 ARCHAEOLOGICAL RESOURCE: RESULTS ....................................................... 133 6.1 Introduction ....................................................................................................... 133 6.2 The Distribution of Archaeological Sites within the Lower Ribble Valley ...... 133 6.3 Examination of the Density of Sites ................................................................. 139 6.4 Monuments, Events, and the HLC .................................................................... 140 6.5 Analysis of the Lacunae .................................................................................... 145 6.6 Statistical Analysis ............................................................................................ 146 6.7 HLC Enhancement ............................................................................................ 153 7 SAND AND GRAVEL RESERVES OF THE RIBBLE REGION ................................. 161 7.1 Existing Knowledge Base ................................................................................. 161 7.2 Revised Sand and Gravel Mapping for the Ribble ........................................... 163 8 DYNAMIC GEOMORPHOLOGICAL MODELLING STUDIES ................................ 175 8.1 Landscape Change under Present-Day Hydrological Conditions ..................... 175 8.2 Landscape Change under Future Hydrological Conditions .............................. 176 8.3 Flood Risk Dynamics ........................................................................................ 177 8.4 Summary ........................................................................................................... 178 9 ANALYSIS AND DISCUSSION .............................................................................. 179 9.1 The Superimposition of the Archaeological Resource on the Aggregate Terraces ............................................................................................................. 179 9.2 The Impact of Geomorphological Change on the Archaeological Resource .... 181 9.3 The Impact of Aggregate Extraction on the Archaeological Resource ............ 187 10 RECOMMENDATIONS ........................................................................................ 190 10.1 Introduction ....................................................................................................... 190 10.2 Further Work ..................................................................................................... 190 10.3 Future environmental and geomorphological