East Lothian Geodiversity Audit

K Whitbread, R Ellen, E Callaghan, J E Gordon and S Arkley

East Lothian Geodiversity Audit Geology and Landscape Scotland Programme Open Report OR/14/063

British Geological Survey

Geology and Landscape Scotland Programme Open Report OR/14/063

The National Grid and other Ordnance Survey data are used with the permission of the Controller of Her Majesty’s Stationery Office.

Licence No: 100017897/ 2015.

Keywords East Lothian, Geodiversity, Quaternary, Carboniferous, Devonian, Silurian-Ordovician.

(Front cover) Image: View of Dunbar shore, looking North-west. © Sarah Arkley, BGS/NERC

Bibliographical reference Whitbread, K, Ellen, R, Callaghan, E, Gordon, J E and Arkley, S 2015. East Lothian Geodiversity Audit. British Geological Survey Open Report, OR/14/063. 192pp.

Copyright in materials derived from the British Geological Survey’s work is owned by the Natural Environment Research Council (NERC) and/or the authority that commissioned the work. You may not copy or adapt this publication without first obtaining permission. Contact the BGS Intellectual Property Rights Section, British Geological Survey, Keyworth, e-mail ipr@bgs.ac.uk. You may quote extracts of a reasonable length without prior permission, provided a full acknowledgement is given of the source of the extract.

Maps and diagrams in this book use topography based on Ordnance Survey mapping.

© NERC 2015. All rights reserved

Edinburgh, Scotland British Geological Survey 2015

Foreword

Constant development pressure on Scotland’s land and resources demands a greater awareness and understanding of the dynamics of our natural world in order to deliver a sustainable environment for the future. Geodiversity is an important environmental asset, linking people, places, rocks, soils, landscape and ecosystems, but it remains one of the least recognised and appreciated.

In East Lothian, several nationally and internationally important geological sites have previously been identified and protected by statutory measures (Sites of Special Scientific Interest). However, these sites form only a limited part of the area’s geodiversity. In order to recognise and protect a broader range of important geological and geomorphological features in East Lothian, East Lothian Council has commissioned the British Geological Survey (BGS) to audit and assess the geodiversity of East Lothian.

This report produced by BGS is a systematic inventory and evaluation of geodiversity sites in East Lothian. This audit has the potential to help inform planning policy and planning decisions with respect to the protection of the area’s geodiversity. It also may provide an information resource to support education, and management activities that promote the preservation of geodiversity sites and geological resources.

Acknowledgements

This project was funded by East Lothian Council and the British Geological Survey.

The authors wish to express their thanks to Jean Squires and Stuart MacPherson from East Lothian Council. We are indebted to John Gordon for the survey of Quaternary sites and contribution to the report. Information on potential sites was provided by David McAdam, Mike Browne and Angus Miller from Lothian and Borders GeoConservation Group.

Maps and diagrams have been prepared by the authors, except where stated. This report includes mapping data licensed from Ordnance Survey with permission of the Controller of Her Majesty's Stationery Office © Crown Copyright and database right [2014].

Contents

Foreword

Acknowledgements

Contents

Summary

1 Introduction

1.1 Background

1.2 Aims and objectives

1.3 Methodology

1.4 Structure of the report

1.5 What is geodiversity?

1.6 Why conserve geological features

2 East Lothian’s Geoheritage

2.1 Bedrock geology

2.2 Quaternary geology

2.3 Geological SSSIS in East Lothian

2.4 Geological resources and the built heritage

3 Evaluating East Lothian’s Geodiversity

3.1 Audit site selection: Data sources and criteria

3.2 Geodiversity auditing

3.3 Defining site boundaries

3.4 Geology and geoscientific merit

3.5 Cultural, heritage and economic importance

3.6 Site condition, access and safety

4 Site Assessments

5 Summary

5.1 Bedrock exposures

5.2 Quaternary and recent deposits and landforms

5.3 Geodiversity and community

5.4 Limitations and potential further assessments

Appendix 1 Geological Conservation Review Sites

Appendix 2 Lothian and Borders GeoConservation Publications

Appendix 3 Chemical classification of fine-grained crystalline rocks

Glossary

References

Figures

(Figure 1) Location of East Lothian Council area.

(Figure 2) Simplified geological map of the Midland Valley of Scotland.

(Figure 3) Bedrock geology of East Lothian (BGS 1:625k digital geological maps)

(Figure 4) Superficial deposits map of East Lothian

(Figure 5) Location map of East Lothian Geodiversity Sites

Tables

(Table 1) Classification of the Carboniferous strata in the Midland Valley of Scotland.

(Table 2) Sites of Special Scientific Interest in East Lothian

(Table 3) List of geodiversity sites in East Lothian

(Table 4) Site Type classification scheme

(Table 5) Current Use classification scheme

(Table 6) Geoscientific Merit criteria

(Table 7) Summary of ratings for East Lothian Geodiversity sites

(Table 8) Geological features present at the Geodiversity Sites

Summary

This report describes a geodiversity audit of East Lothian carried out by the British Geological Survey (BGS) on behalf of East Lothian Council (ELC). The audit comprised a desk review of potential geodiversity sites, field assessments, evaluation of the geodiversity sites and reporting.

Potential local geodiversity sites were identified by contacts in the Lothian and Borders Geoconservation Group (formerly RIGS). Information on the potential sites from BGS records and published sources was reviewed, including digital geological maps and historic field slips, digital aerial photography, and published papers, memoirs and reports. Documentation for sites previously identified as Sites of Special Scientific Interest (SSSI) and/or Geological Conservation Review (GCR) sites was also reviewed. Due to their current protected status, sites designated as SSSIs for their geological features were not selected for the geodiversity audit with the exception of coastal sites located within the large Firth of Forth SSSI notified for both biological and geological features.

Field assessments of 30 of the sites identified by Lothian and Borders Geoconservation with the highest potential geodiversity value were conducted during 2014. Information on the geoscientific merit, cultural heritage, economic importance, access, site condition and fragility education potential, and community associations of the sites was recorded. Geoscientific merit is evaluated in terms of the rarity and quality of the features displayed at the site.

A total of 21 bedrock or mixed bedrock and Quaternary sites, and 9 Quaternary sites were identified as candidates for designation as local geodiversity sites in East Lothian. The sites selected include the best examples of geological and geomorphological features in the region and are considered to be representative of the diverse range of geological strata and landforms that characterise the geology of the region. The sites include excellent examples of Carboniferous, Devonian and Silurian/Ordovician strata that are exposed across central and southern Scotland, and landforms that are classic examples of Quaternary glacial features in lowland terrains and important coastal geomorphology systems. The sites also have numerous links to the character of the landscape, historical features, ecology, and the economic and cultural history of the area.

Many of these sites have the potential to be enhanced through interpretation to encourage visitors and students to learn more about geology and the relationship between rocks, landscape and ecosystems, and the links between the geology and the economic and cultural heritage of the East Lothian area.

1 Introduction

The British Geological Survey (BGS) was commissioned by East Lothian Council (ELC) to carry out a review of sites of geological and geomorphological significance within the local authority area. The study has taken the form of a geodiversity audit to assist in future planning, development and conservation issues. The work was co-funded by BGS Scotland.

This work was undertaken in the spring and summer of 2014 with a desk-top review of BGS records and published literature followed by field visits to gather new geodiversity information. This report describes, illustrates and evaluates 30 geological sites in East Lothian that are considered to best represent the geological diversity of the area.

Recommended boundary lines defining the site areas have also been supplied to ELC in GIS format (ESRI Shapefile) to supplement the information provided in this report. The Shapefile version of the boundary lines should be regarded as the definitive version for reference purposes.

1.1 Background

East Lothian Council recognises the importance of conserving the region’s geodiversity and preserving landscape features, in particular those geological features that may be considered as Local Geodiversity Sites (formerly termed Regionally Important Geological and Geomorphological Sites or RIGS).

Nationally designated sites such as Sites of Special Scientific Interest (SSSIs) or Geological Conservation Review sites (GCRs) protect only a limited part of the area’s geodiversity. ELC have commissioned the BGS to evaluate a range of geological and landscape features in East Lothian in addition to those that currently have SSSI status. The audit builds on previous work by volunteers of the Lothian and Borders Geoconservation group in identifying and describing many of the areas important geological features.

The audit of East Lothian Geodiversity is intended to form the basis for designation and protection of Local Geodiversity Sites, with a comparable status to Local Biodiversity Sites within the planning framework. The audit will also provide ELC with information that may be used to enhance the quality of their geological sites and to develop public engagement and education initiatives.

1.2 Aims and objectives

The principal aim of the study is to identify and formally assess the key geodiversity sites in East Lothian. These sites are selected to represent the diverse geology and geomorphology of the area.

The objectives of the study are:

1. To review existing designated geological sites (SSSIs) and identify potential geodiversity sites with no current designation.
2. To evaluate the geodiversity of each site based on criteria that consider the scientific, educational, cultural and community merits.
3. To delineate site boundaries that encompass the key geological features of the site and sufficient area to allow them to be viewed, 4. To review the condition of the sites and, where appropriate, to make suggestions for potential improvements in the management, access and education potential of the site.

1.3 Methodology

The objectives have been addressed through three stages of work: an initial desktop review of published literature and BGS archive records to identify potential sites; field assessments of the geodiversity sites; and finally analysis and reporting of the geodiversity valuations.

1.4 Structure of the report

An overview of the geology of East Lothian is presented in chapter 2, including the bedrock (solid) geology and the overlying Quaternary (superficial) deposits. Chapter 3 describes the methods used to identify potential geodiversity sites, the criteria used in their evaluation and the procedures used in the field assessments.

Chapter 4 provides detailed site assessments for each of the geodiversity sites, and forms the main part of the report. The information is presented as a set of pro-forma sheets containing:

• General location and background information
• A location map
• A summary description
• A review of the condition, access and safety of the site
• An assessment of the sites GeoScientific Merit
• The site evaluation (including the overall Geodiversity value statement)
• A review of the cultural, heritage and economic associations
• Site photographs

The results of the audit are summarised and discussed in chapter 5.

1.5 What is geodiversity?

Geodiversity has many definitions, but essentially describes the variety of rocks, minerals and fossils, landforms and landscapes, active geological processes and soils and subsoils (Quaternary deposits) of an area. These elements interlink and together determine not only the form our natural environment but also the character of local wildlife habitats and ecosystems.

Geodiversity also has strong links to the social, cultural and economic heritage of the people of East Lothian. The locations of settlements, abstraction of minerals and the use of local stone in buildings and infrastructure give a distinct character to the region and typify the strong links between our human heritage and our geodiversity.

1.6 Why conserve geological features

Despite wide preservation and protection of biodiversity sites, the geodiversity that underpins the stability of ecosystems and contributes to our economic, social and cultural heritage has only limited protection within the planning system. Current protection for geological sites in Scotland is restricted to the sites that are designated as SSSIs.

Geodiversity is an integral part of nature. It has intrinsic (geoheritage), scientific, educational, cultural, ecological and ecosystem service values. These values are vulnerable to a wide range of threats; quarries can be infilled, natural overgrowth by vegetation can obscure exposures, features within an urban environment may be built over, and landforms may be removed or remodelled during excavation or development. Our understanding of the geological processes and landscape history of Scotland, and the wider UK, depends on access to key sites from which the diverse nature of rocks can be directly observed. These sites preserve our geological heritage. They are fundamental not only for scientific research and education, but often have cultural and aesthetic values that provide connections between people and place. Many also support highly valued ecosystems, habitats and species, while others are assets for recreation and tourism. Hence, it is vital that geodiversity sites are protected so that our geoheritage can be maintained and appreciated by future generations.

2 East Lothian’s Geoheritage

The East Lothian Council area lies in the south east of Scotland, bordered by the Firth of Forth and the North Sea on its northern and eastern sides, and by the Scottish Borders to the south and Midlothian (/Edinburgh) to the south and west (Figure 1).

East Lothian is renowned for its attractive rural landscape and beautiful coastline. These features have their origins in the underlying geology and the geological processes that act upon the land. The diverse bedrock that underlies East Lothian has been sculpted by the erosion of rivers, glaciers and the sea over recent geological past (the Quaternary period). Landforms and deposits from the recent processes form characteristic features in the landscape. Furthermore, the picturesque towns and villages owe their distinct regional character to the local stone used in the walls and buildings.

In the following review of the bedrock and superficial (Quaternary) geology of East Lothian, information was derived from the published geological maps of the area; BGS 1: 50 000 scale map sheets 32E (Edinburgh), 33W (Haddington), 33E (Dunbar), 41 (North Berwick), and the geological memoir for Haddington (McAdam and Tulloch, 1985).

2.1 Bedrock geology

East Lothian lies across the south-eastern margin of the Midland Valley of Scotland. The Midland Valley is the name given to the relatively low lying part of central Scotland located between the uplands of the Scottish Highlands to the north and the Southern Uplands to the south. Geologically it is defined by two large fault systems: the Highland Boundary Fault, which lies to the north and extends from Stonehaven in the northeast to the Firth of Clyde at Helensburgh, and the Southern Upland Fault which extends from Dunbar to Glen App. The downfaulted area between the two faults contains rocks of mainly Carboniferous and Devonian age (Figure 2, Figure 3).

The Southern Upland Fault bisects the landscape of East Lothian, separating the upland moors of the Lammermuir Hills to the south-east from lower, rolling terrain in the north-west that stretches from Haddington and Pencaitland to the coast. In this area, the Southern Upland Fault system comprises two faults, the southern Lammermuir Fault and the Dunbar-Gifford Fault.

Note: The Laggan Cottage Mudstone Formation of north Arran and the Birgidale Formation of south Bute at the base of the Strathclyde Group are not shown. Nor are the Bathgate hills, Kinghorn and Salsburgh Volcanic formations of the Bathgate Group.

To the north of the Lammermuir Fault, the rocks that crop out in the East Lothian area are of late Devonian to Carboniferous age (380–360 Ma). These rocks consist of a sequence of sedimentary and igneous strata that were laid down in a gradually subsiding basin. During the late Devonian and early Carboniferous, rivers traversing a hot, humid lowland plain deposited sand and mud, which was colonised by early land plants. These sediments later formed the variable sequence of sandstone, siltstone, mudstone, dolomitic limestone and seatearths (preserved soils) known as the Ballagan Formation. The rich late Devonian environment of rivers and shallow-water lakes formed an ideal setting for the evolution of land-going animals (tetrapods), and the study of early tetrapod fossils found in the Ballagan Formation of the Scottish Borders and East Lothian, as well as the environment in which they lived, is a key area of current geological research.

Later Carboniferous rocks (360–300 Ma) are represented in East Lothian by a sequence of volcanic and sedimentary strata (Strathclyde Group), with older rocks exposed in the east and younger rocks to the west. The Garleton Hills Volcanic Formation, a sequence of lavas and tuffs (volcanic ash deposits) formed during a period of eruptive volcanism during the mid-Carboniferous, crop out at the base of the Strathclyde Group in the east of the area and are exposed along the coast near North Berwick. Overlying the volcanic rocks to the west are a series of units of sedimentary rocks including sandstones, mudstones and limestones deposited in varying marine, shallow marine, and terrestrial fluvial environments arising from changes in relative sea level during the mid to late Carboniferous. The youngest rocks in East Lothian comprise strata of the Coal Measures Group (Scotland) formed by cyclic deposition of sandstone, mudstone, siltstone and coal in a swampy forest environment crossed by large river systems.

The sequence of Carboniferous rock units in East Lothian is shown in (Table 1).

2.2 Quaternary geology

East Lothian displays a diverse range of glacial and coastal landforms and deposits (Figure 4), which reflect the influence of erosion and deposition during the past 2.6 million years, a time known as the Quaternary period. During the Quaternary, Scotland was covered repeatedly by large ice sheets that extended from the mountains westwards across the continental shelf and eastwards across the floor of the North Sea to merge with Scandinavian ice. Along the coast, the position of the coastal edge changed as sea-levels fell and rose as the glaciers expanded and retreated. In East Lothian, most of the glacial evidence relates to events during the most recent glaciation, the Late Devensian (c. 31–11.7 Ka). During this time, large glaciers sourced in the Highlands and Southern Uplands, coalesced in the southern part of the Midland Valley to form a vast sheet of ice that streamed across the area towards the east. Erosion beneath this large glacier has left a legacy of scoured bedrock and streamlined deposits across the East Lothian landscape.

The broad outlines of the landscape of East Lothian reflect differential erosion of the varied sedimentary and volcanic rocks over many millions of years. North of the Southern Upland Fault, the more resistant volcanic rocks generally form areas of upstanding relief that have been streamlined or eroded into crag-and-tail landforms by glacial scouring (e.g. the Garleton Hills, North Berwick Law, Traprain Law). The lower ground is extensively mantled by till which was deposited and streamlined by the glacier ice, and by sand and gravel deposited by meltwater streams flowing beneath or adjacent to the Late Devensian ice sheet. Erratic boulders, including metamorphic rocks of Highland origin, commonly occur along the coast and are particularly well displayed where they have been washed out of till along the shore platforms. At Kidlaw, a mass of limestone c. 0.2 km² forms the largest known erratic in Scotland (Kendall & Bailey, 1908). Meltwater channels carved into till and bedrock by subglacial and ice marginal streams, are common along the northern flanks of the Lammermuir Hills, where they are associated with kame terraces, ice-marginal lake deltas.

As the climate warmed rapidly after 15 ka, the ice retreated from the lowlands and vegetation became established. As the ice receded, relative sea-level rose and the sea invaded the lower parts of the coastline forming Lateglacial raised shorelines along many areas of the East Lothian coast. In the Tyne estuary, cold-water estuarine deposits containing arctic marine fossils were laid down adjacent to the retreating glaciers. In a former claypit at West Barns, bones of a Ringed seal (Phoca hispida) were also recovered (Peacock, 1999; Davies et al., 1986). The subsequent return of a severely cold climate gave rise to periglacial conditions between 12.9–11.7 ka. During this period, slope and fluvial activity were enhanced; thick slope deposits (head) accumulated on the lower slopes of the Lammermuir Hills, and talus formed in the Garleton Hills.

During early postglacial times, a further period of higher relative sea level culminated after around 7000 years ago. Subsequent changes in relative sea level produced further raised shorelines along many parts of the coast. As the sea dropped to its present level, continued reworking of the coastal sediments has formed extensive sandy beach and sand dune systems in many bays, as well as areas of mudflats and saltmarshes. In an embayment at Lochhouses, layers of marine deposits occur behind the coastal dune barrier (Newey, 1965; Robinson, 1982). One of these sand layers is attributed to a tsunami generated by a massive landslide on the Norwegian slope 8100 years ago (Smith et al., 2004).

Erosional coastal landforms including shore platforms and cliffs of various ages occur along the coast. The interplay between coastal erosion and the different volcanic and sedimentary rocks has produced a variety of distinctive headlands, stacks, natural arches and cliffed islands such as the Bass Rock.

Inland from the coast, postglacial rivers have adjusted to changing discharges and sediment loads as reflected in terrace formation, floodplain development, abandonment of meanders and abandoned channels including those on the lower River Tyne. On upland slopes, gullying processes in weathered bedrock have resulted in the formation of areas of ‘badland’ topography in the Lammermuir Hills (Werritty & McEwen, 1997).

2.3 Geological SSSI's in East Lothian

Sites of Special Scientific Interest are areas designated by Scottish Natural Heritage (SNH) under the Nature Conservation (Scotland) Act 2004. These sites are representative of features of our natural heritage and include examples of plant and animal habitats, rocks and landforms that are considered to be nationally important.

There are 15 SSSIs in the East Lothian area, of which seven have been designated wholly or in part due to their geological or geomorphological features (Table 2). With one exception, the large Firth of Forth SSSI, the geological SSSIs have not been included as geodiversity sites in this audit due to their pre-existing designation. The geological SSSIs should be viewed as key geodiversity sites in conjunction with the sites identified in this report.

The Firth of Forth SSSI covers 74 km² of coastline along the full length of the northern and southern margins of the Firth of Forth, including many areas of the East Lothian coast. This large SSSI has been designated for both its biological and geological importance. However, the size of the site means that particular geological significance of specific areas of the East Lothian coast included within the SSSI is not fully represented. Geodiversity sites located along sections of the East Lothian coastal zone that fall within the Firth of Forth SSSI have been identified in this report. The designation of these sites within the Firth of Forth SSSI is noted in the site assessments.

2.4 Geological resources and the built heritage

Geological resources include building stones and minerals that are extracted for construction materials and energy generation. In the west of East Lothian, coal has been extracted from strata of the Coal Measures Group since the 13^th century and the landscape bears many reminders of the former mining activity including disused shafts and adits. The mining heritage has also influenced the development of towns and villages in the area and is reflected in many of the local place names. In addition to mining, industries such as brick production have historically provided other important connections between the geology and the economy of East Lothian.

Local sandstone, extracted from numerous small quarries in the Carboniferous sedimentary strata, has been used in many of the historic buildings found in East Lothian from the region’s castles to its cottages. The use of local stone lends a distinct character to many of the picturesque villages.

Igneous rocks have also been quarried in many areas for road stone. Small but distinctive quarries are found on some of the prominent igneous landforms of the region such as Traprain Law (and SSSI) and North Berwick Law. Quarries in the extrusive igneous strata of the Garleton Hills were important early sites for the study of these rock types. Several quarries in the region became type sites for early classification schemes of volcanic rocks with the names of the quarries used to denote the distinct types of basaltic rocks they contain (e.g. Dunsapie and Markle).

The distinct rocky coastline of East Lothian has exerted an important control on the siting of harbours and their associated towns and villages. The strong geological influence on the form of the harbour and its development is evident in Dunbar for example. The strategic importance of these harbours for trade and commerce can also be seen in the presence of historic military sites (including castles) along the East Lothian coast.

3 Evaluating East Lothian’s Geodiversity

3.1 Audit site selection: data sources and criteria

Potential geodiversity sites were identified by review of available documents and datasets, and through consultation with members of Lothian & Borders Geoconservation. Information sources consulted included:

• SSSI and GCR documentation (SNH)
• BGS 1:10 000 geological standards maps and fieldslips
• BGS BritPits database of Mines and Quarries
• The Haddington Geological Memoir (McAdam and Tulloch, 1985)
• Lothian Geology: An excursion guide (A D McAdam & E N K Clarkson, 1986)
• Existing scientific literature

From this assessment, 31 potential geodiversity sites were identified for field assessment (Table 3), (Figure 5) based on their geoscientific merit according to criteria for valuing the educational, scientific, historical and aesthetic value of sites developed by GeoConservation UK (RIGS).

The selection of sites was made to ensure a comprehensive geological and geographical spread within the East Lothian area, with a focus on the highest quality and most significant geological features of the region.

3.2 Geodiversity auditing

Field auditing was carried out between March and December 2014 by BGS staff (Rachael Ellen, Elieen Callaghan, Sarah Arkley, Katie Whitbread, Hugh Barron and David Millward), with assistance from Mike Browne (Lothian and Borders Geoconservation). The Quaternary sites were audited on behalf of the BGS by John Gordon (Scottish Geodiversity Forum). The criteria used to evaluate the sites are discussed below. As far as possible landowners were contacted prior to visiting or accessing sites, but it was not possible to establish ownership for every site visited.

Data were collated digitally in ARC GIS and reviewed with information from aerial photography, Ordnance Survey topographic maps and BGS digital geological datasets. Site boundaries (discussed below) and key audit data have been supplied to ELC in conjunction with this report.

Of the 31 potential local geodiversity sites identified for field assessment, full audits were conducted at 30. The remaining site, several disused sandstone quarries near Gullane was not audited as the quarries are now fully overgrown and no rock exposures were found.

3.3 Defining site boundaries

The site areas have been delineated through the generation of Shapefiles in ESRI ArcGIS. The method used for delineating site boundaries was developed in discussion with East Lothian Council officers.

The site boundary defines the total area considered to be integral to the geodiversity site and is consistent with a suggested protection zone that is considered to necessary to maintain the integrity of the geodiversity site.

The site boundary may comprise one or a number of areas of exposed geological features including rock outcrops, landforms and any adjacent geologically significant areas considered integral to the site due to landscape and access considerations. In coastal areas, the site boundaries extend offshore to the Mean Low Water Springs defined on Ordnance Survey 1:10,000 scale topographic maps.

The site boundaries are displayed in the maps in the attached site valuations and have been provided as a separate ArcGIS Shapefile. The Shapefile should be regarded as providing the definitive site boundary for reference purposes.

3.4 Geology and geoscientific merit

The geodiversity site is considered to be represented by the area within the Site Boundary. The assessment of the site condition and valuation of the geodiversity applies to all components of the site that lie within the Site Boundary area.

3.4.1 Site type

Geodiversity sites are classified according to the type of exposure or feature and the current use of the site (Table 4), (Table 5).

3.4.2 Stratigraphy and rock types

The chronostratigraphic age (e.g. ‘Carboniferous’), lithostratigraphic group and formation (Table 1), as well as the main lithogy for each site are recorded for reference purposes. More details of the main lithologies, their relation to any sub-lithologies that may be present, and the nature of geological structures or other features of interest are given in the geological description.

3.4.3 Geoscientific merit criteria

The geodiversity sites have been evaluated according to their geoscientific importance which has been assessed in terms of the relative rarity and quality of key geological or geomorphological attributes that can be seen at the site. The key attributes assessed are:

• Lithostratigraphy – features indicative of an important stratigraphic horizon and helping to define the sequence of geological strata,
• Sedimentology – features related to depositional processes and settings,
• Igneous/Mineral/Metamorphic – intrusive or extrusive igneous rocks, metamorphic rocks and minerals, and mineral vein deposits,
• Structural geology – faults, folds, shear zones or other deformation features,
• Palaeontology – fossils or trace fossils,
• Geomorphology – landforms and features representative of, or demonstrating, key depositional and erosional processes occurring at the earth’s surface.

A single site may have more than one attribute, but is unlikely to have all of them. The rarity and quality of the site attributes have been scaled using the classification schemes defined in (Table 6).

Where published materials, such as articles or books, provide details of aspects of the sites geology, the literature sources are also noted. Unpublished materials such as leaflets may be available for some sites, and may be mentioned elsewhere in the site report.

An overall geoscientific merit value statement represents the overall geoscientific value of the site using the rarity and quality scales in (Table 6). The overall value summarises the scaling for the relevant attributes, but also includes consideration of the relative importance of the site in terms of its geological uniqueness or conversely, the degree to which it is representative of a larger terrain or unit. For instance a site may be of high value because it is extremely rare, but also because it is an excellent example of rocks that are characteristic of a particular geological terrain or time period.

3.5 Cultural, heritage and economic importance

Known associations between the geodiversity of a site and people (whether locally or nationally) are discussed in terms of aesthetic, historical and economic associations. Cultural associations may include literary, aesthetic, musical or social connections, or sites that have significance for the development of the study of the earth sciences. Historical associations may reflect past military, religious or cultural connections, particularly those associated with strategic landform sites. The extraction of building stone and natural resources including coal and lime are considered in terms of economic associations, these may be active or historic.

The potential uses of the site for research, higher/further education, school education or community development were considered along with potential development activities or information materials that could enhance the use of the site by the local community, education groups and other visitors.

3.6 Site condition, access and safety

3.6.1 Access and Safety

The nature of access routes to enter or view sites is an important consideration. The ease of road access and parking, near to the site, along with considerations of the safety of access paths and the safety and condition of the exposure are described in the site report.

Current conflicting activities and restricting conditions, such as tides, shooting restrictions and other activities for which the sites may be used are noted in the report. These are known activities only, and it should be noted that there may be further restrictions to site access that are not known to the authors. Visitors to the sites are responsible for preparing their own risk assessments where necessary. The Scottish Outdoor Access Code provides further information on land access in Scotland.

3.6.2 Fragility

The condition of each site and the stability of rock or sediment exposures were assessed visually during the field survey. Full ground stability assessments were beyond the scope of the survey. Factors affecting the condition of rock exposures at the sites include weathering/erosion, natural overgrowth of vegetation, the effects of sample/fossil collecting, fly tipping and the dumping of waste and construction or other development activities.

4 Site assessments

This section contains the completed audit forms giving details of each site, geological descriptions, and the geodiversity value.

(Figure 1) Location of East Lothian Council area (pink outline) and the distribution of 1: 50 000 scale BGS geological map sheets (blue lines).

(Figure 2) Simplified geological map of the Midland Valley of Scotland. Geological faults are shown by a thick black line with a tick on the downthrown side (Source: BGS DiGMapGB data).

(Figure 3) Bedrock geology of East Lothian

(Figure 4) Superficial deposits of East Lothian

(Figure 5) Location map of East Lothian Geodiversity Sites

(Table 1) Classification of the Carboniferous strata in the Midland Valley of Scotland Older, Lower Palaeozoic rocks (460 – 430 Ma) crop out to the south of the Lammermuir Fault, represented by fissile sandstones and siltstones known as greywacke that underlie the Southern Upland terrain. In the east, these rocks are overlain by conglomeratic rocks of Lower Devonian age (430 – 390 Ma) that were once deposited over the eroded surface of the Lower Palaeozoic rocks by large rivers.

(Table 2) Sites of Special Scientific Interest in East Lothian

(Table 3) List of geodiversity sites in East Lothian and sites visited but not included as geodiversity sites

(Table 4) Site Type classification scheme

(Table 5) Current Use classification scheme

(Table 6) Geoscientific Merit criteria (NB: Midland Valley refers to the region between the Southern Uplands in the south and the Highland Boundary Fault in the north)

References