Information and Advisory Note Number 40 Back to menu
1.1 This Note refers to mineral extraction, mainly of sand and gravel, in relict surface deposits and landforms produced by glacial meltwaters and sea-level changes at the end of the Quaternary Ice Age. It describes the impacts on the earth science interest of such features and provides guidelines for responding to development applications. The landforms and deposits concerned include features such as eskers (Figure 1), kames, kame terraces, outwash terraces, deltas and raised beaches that occur in Geological Conservation Review (6CR) sites and Regionally Important Geological and Geomorphological Sites (RIGS), as well as in other non-designated sites. The note covers only the earth science interest in such sites. Other conservation interests, including biological and landscape features, may also need to be evaluated in formulating an overall.
response to a particular development application and appropriate advice sought
from other branches of RASD, Policy Directorate and Regional Advisory Services.
Advice on extraction from active process sites, such as rivers and beach or dune
systems, will be covered in separate Information and Advisory Notes.
1.2 The interests of Quaternary deposits may be the landforms themselves (i.e.
their size, shape and distribution) and/or the internal structure of the
deposits and the composition of the constituent sediments (Figure 2). Since the
impact of any development will vary according to the interest, it is important
to know the precise nature of the latter (landforms, sediments or both) as this
will determine the management response.
2.1 The principal activity of concern is sand and gravel extraction. This may
occur as large scale, commercial development requiring planning consent or as
small scale
activity which falls under notifiable activities for Sites of Special Scientific
Interest (SSSIs) notified under the Wildlife and Countryside Act 1981.
Applications may be for extraction from new sites or for extensions to existing
workings or disused pits.
2.2 Hard rock quarries or open-cast mining may also involve removal of
superficial deposits or destruction of landforms, and the same general
guidelines apply.
3.1 Quarrying can have both positive and negative impacts; for example through the
exposure of new sections, it may provide access to new scientific information on
the composition of the deposits and their evolution, sometimes on a scale which
cannot be achieved in natural exposures or excavations for scientific purposes.
These benefits, however, may be derived at the cost of destroying the resource
(Figure 3), and generally the presumption will be that the negative impacts of
large-scale, commercial quarrying will outweigh the advantages, particularly as
far as new developments affecting SSSIs and RIGS are concerned.
3.2 The predominance of negative impacts arises from the relict nature of the
features of interest. They are relict in the sense that they formed in the past
by processes that are no longer operating. This has three principal
implications:
3.3 In general, the negative impacts of mineral extraction on the scientific interest of Quaternary landforms and deposits may involve:
Figure 3. Quarrying of sand and gravel deposits may reveal
useful scientific information about their sedimentary architecture and origins,
but where this is on a large scale in relation to the extent of the landforms
then it occurs at the expense of the loss of the surface landforms.
3.4 Although it is possible that the interest
could be studied and documented before
development destroys the landforms On a
manner comparable to rescue digs in
archaeology), this approach in general is not
considered appropriate where:
3.5 The same considerations apply to small-
scale, non-commercial extraction. However,
the impacts are generally likely to be less
severe and there may be clear advantages in
revealing new scientific interests; for example,
a small number of GCR sites in Scotland owe
their discovery to small scale quarrying
(Figure 4).
Figure 4. Teindland Quarry SSSI is a former gravel pit where small-scale
extraction revealed a unique sequence of deposits, including a palaeosol
(fossil' soil), that provides important evidence for environmental and landscape
changes in NE Scotland during the Quaternary. The site is now managed for its
Earth science interest.
4.1 Management options are considered in relation to existing working quarries and
proposals for new developments. The distinction is also made between
large-scale, commercial extraction and small-scale, non-commercial extraction.
4.2 Existing working quarries
4.2.1 Where significant scientific interest is discovered in sections exposed
during the working life of quarries with existing planning consent, the
objectives are to ensure that this interest is adequately documented and, if
appropriate, representative sections conserved for the use of future generations
after working ceases. The following guidelines are recommended:
1. A basic premise is that there should be no obstruction of working operations;
the preferred approach is to work with quarry operators and to persuade them of
the significance of the find, particularly since co-operation depends on their
goodwill -there are no statutory requirements as for rescue archaeology.
2. Access should be negotiated where possible for bona fide earth scientists to
study and record the exposed sections and to assess their significance.
3. Where the interest is of substantial significance (e.g.. GCR standard),
consideration should be given to the negotiation of a conservation section to be
set aside when working ceases. The practicality of such a proposal needs to be
evaluated in respect of after use and the restoration conditions specified in the
original planning consent. It will also depend on site conditions (e.g.
groundwater levels or risk of pollution by leachate from any landfill), the
location of the interest within the site, the height and stability of proposed
sections and future ownership and management. Generally, a small section near
the margins of the worked area will be practicable; a large section, or a
section deep in the middle of a quarry will not be practicable. For further
guidance in this area, see Information and Advisory Note No. 41: 'Restoration
and management of mineral extraction sites in Quaternary landforms and
deposits'.
4.3 Existing pits: small-scale, non-commercial extraction
4.3.1 Normally, intermittent small-scale extraction from pits will be a notifiable
operation for sites with Quaternary landforms and deposits notified under the
Wildlife and Countryside Act 1981. In most cases where sites are notified for
sediment interests, consent will be given for the continuation of the activity
unless it is demonstrably damaging to crucial zones of interest identified in
the appropriate Earth Science Site Documentation Report/Site Management Brief.
Often such activity helps to maintain clear exposures for demonstration
purposes. Where sites are notified principally for landforms, then it is
essential to ensure that the interest is not destroyed through slow expansion of
the extraction area. It is therefore important to monitor any changes to the
site. Where applications are received for new consents, the volume of material
and the location of extraction should be agreed. For sensitive sites, it may
also be appropriate to attempt to negotiate a time limit on the period of
extraction (say for 5 years), to allow reassessment of impacts.
4.3.2 Similarly, for RIGS and other non-designated sites, intermittent extraction
may help maintain fresh exposures for study and demonstration purposes. Again
monitoring should be undertaken to allow assessment of changes detrimental to
the interest of the site.
4.4 Proposed developments: large scale
4.4.1 In considering the response to new
developments requiring planning consent, the
following questions should be considered:
4.4.2 The Site Documentation Reports/Site
Management Briefs should help to suggest
answers to these questions. In the light of the
answers, the options for the response are as
follows (see SNH Scottish Local Authorities
Handbook: Section D18 and Appendix V).
1. No objection - no suggested modifications. This would normally be the
response where the development is relatively small in scale and in an area of
limited scientific interest in a context area. This option is rarely likely to
apply.
2. No objection subject to conditions or modifications. This response may arise
where clear scientific benefits would result from the exposure of new sections,
but only if these are property documented and studied and there is no
significant loss of key landforms. This situation would normally apply where a
proposed development is in a context zone, but might occasionally apply to a
crucial zone. Recommended conditions might include requirements for baseline
survey of any landforms that would be destroyed, access by geologists to monitor
and record the working faces and/or the setting aside of a conservation section
when working ceases.
3. Holding objection -insufficient time or information (see advice in SNH
Scottish Local Authorities Handbook).
4. Full objection - where development (even with conditions or minor
modifications) is unacceptable. This would normally be the response where
landforms are the prime interest and the development is located in a key area.
Where the response is likely to be option 4, further guidance should be sought
from the SNH Policy Guidance Summary on Planning Inquiries.
4.5 Proposed developments: small scale,
non-commercial extraction
Where new pits are proposed, then assessment of the impact should be made in the
light of the answers to the questions in section 4.4.1 above, bearing in mind
that limited extraction may provide useful sections for demonstration purposes.
In general, small scale extraction will be more acceptable within context zones.
Within crucial zones, consent for extraction will depend on the specific
circumstances of the proposal, its location and the nature of the scientific
interest. More detailed guidance should be available in the relevant Site
Documentation Reports/Site Management Briefs. As noted in paragraph 4.3, it may
be helpful to attempt to negotiate consents that are time limited and to monitor
the impacts.
4.6 Restoration
Guidelines concerning the subsequent restoration of working quarries and the
management of disused pits and quarries are provided in Information and Advisory
Note No. 41 'Restoration and management of mineral extraction sites in
Quaternary landforms and deposits'.
5. Sources of further advice: relevant authorities and organisations
A number of authorities and organisations have responsibilities or interests in
the working, conservation and management of sand and gravel deposits. The bodies
listed below may be able to give further information and advice as well as
details of local representatives or contacts in your area.
SCOTTISH NATURAL HERITAGE Research and Advisory Services Directorate, 2 Anderson
Place, Edinburgh EH6 5NP (Tel 0131-4474784).
SCOTTISH NATURAL HERITAGE Policy Directorate, 12 Hope Terrace, Edinburgh EH9
2AS. (Tel. 0131-447 4784) -provides advice and information on policy, planning
and countryside conservation issues.
SCOTTISH NATURAL HERITAGE Land Management and Advisory Services in Regional
Headquarters will be able to advise on planning and landscape issues.
QUATERNARY RESEARCH ASSOCIATION (QRA)
Current Secretary: Dr P Coxon, Department of Geography, Museum Building, Trinity
College, Dublin (Tel. 010 353 1 6081213) - Professional association for
individuals and organisations with interests in Quaternary science. Members,
located throughout the whole of Britain, may be able to provide advice and
information on the scientific interests and use of particular areas for research
and teaching purposes. (Note that post of Secretary changes every 4 years. ESB
will be able to advise on the current incumbent).
BRITISH GEOMORPHOLOGICAL RESEARCH GROUP (BGRG) Secretary: Professor I. Foster,
School of natural and Environmental Sciences (Geography), Coventry University,
Priory street, Coventry CV15FB. (Tel. 01203 838404) - Professional association
for individuals and organisations with interests in geomorphology. Members,
located throughout the whole of Britain, may be able to provide advice and
information on the scientific interests and use of particular areas for research
and teaching purposes. (Note that post of Secretary changes every 3 years. ESB
will be able to advise on the current incumbent).
THE GEOLOGISTS' ASSOCIATION General Secretary, Burlington House, Piccadily,
London W1V9AG (Tel: 0171-434 9298). Association for individuals interested in
geology. Members may be able to provide advice and information on the scientific
interests and use of particular areas for research and teaching purposes.
SAND AND GRAVEL ASSOCIATION (SAGA)
1 Bramber Court, 2 Bramber Road, London W14 9PB (Tel. 0171 381 8770) -trade
association for the sand and gravel industry. SAGA operates a Restoration
Guarantee Fund and makes annual awards for site restoration schemes.
6.1 Windyhills SSSI
This site is designated for a deposit of quartzite gravels that provide unique
information about long-term landscape evolution in NE Scotland. There is no
significant surface landform expression, other than the general location of the
deposit on top of a hill, and the interest of the site resides in the buried
gravels. These are revealed in a number of small, non-commercial gravel pits
from which intermittent extraction occurs. The scale of this extraction has been
small and may be regarded as sustainable in the context of the size of the
deposit and from the point of view of allowing a means of access to study the
gravels. Providing that the extraction is monitored, there is no reason why it
should not continue at its present minor level. Conversely, large-scale
commercial extraction of the gravels could not be regarded as a sustainable use
of a natural heritage resource which is not only non-renewable, but also
represents a unique scientific asset. Although information about the deposit
would undoubtedly be gained during extraction, its destruction would deprive
future generations of geologists of the opportunity to study the material in
situ or to apply new research methods that will inevitably be developed. The
argument that a small reserve of the deposit could be set aside as a
conservation site, while better than nothing, would not be a satisfactory
outcome since the loss of the main deposit would deny future study of the
sedimentary variations within the deposit and their 3-dimensional architecture.
6.2 Kildrummie Karnes SSSI
Kildrummie Karnes SSSI is an outstanding example of an esker network formed by
glacial meltwaters at the end of the last ice age. Such landforms comprise sand
and gravel deposits which are naturally of interest to the aggregate industry.
Unlike many other such features, the Kildrummie Karnes landforms are largely
intact and have not been
significantly modified by sand and gravel extraction The prime management
objective for this site is therefore to maintain the integrity of the principal
surface landforms viz. the esker ridges. Therefore any large-scale commercial
sand and gravel extraction would not be appropriate within the core areas of the
site (see Site Documentation Report). Similarly, because of the importance of
the landforms, any small-scale, non-commercial extraction should, in general, be
confined to context areas identified in the Site Documentation Report.
6 3 Achnasheen Terraces SSSI
Achnasheen Terraces SSSI is a classic locality for a series of outwash and delta
terraces formed by glacial meltwater rivers that flowed into a lake dammed by
glaciers at the end of the ice age The interest lies principally in the sinking
topographic form of the terraces, and also in the nature of the deposits that
they comprise. Large-scale commercial quarrying of the deposits would therefore
be quite inappropriate because of the destruction of the landforms. However, a
localised excavation in a context zone might be beneficial to establish a
conservation section to demonstrate the nature of the sediments
6.4 Littlemill Fluvioglacial Landforms SSSI
Littlemill Fluvioglacial Landforms SSSI is important for a suite of large esker
ridges aligned in a parallel arrangement. It illustrates the different impacts
of large-scale commercial quarrying and small-scale extraction. At the time of
SSSI notification, there was an existing planning consent for sand and gravel
extraction from part of the esker formation. The result has been the removal of
one esker ridge and also an important area where the ridges converged on an area
of hummocky ice-contact deposits. The overall integrity of the site and the
evidence for the relationships between the ridges has thus been significantly
damaged by sand and gravel quarrying. Unfortunately, there has been no
systematic documentation of the sections exposed during the period of working
and a valuable scientific resource has been lost for ever. The remainder of the
site, however, still retains sufficient interest to merit SSSI designation; any
large-scale sand and gravel extraction in this area would be incompatible with
conservation of the landform interest. At the SW end of the site a small borrow
pit has been opened by the
Forestry Commission as a source of gravel for surfacing forest roads. This pit
has had a limited impact on the landforms of the core area and provides a
permanent section revealing the structure of the deposits. As such, it may be
regarded as an asset to the interest of the site, provided that it does not
encroach much further into the landforms.
Bridgland, D. R. 1994. The conservation of Quaternary geology in relation to the
sand and gravel extraction industry. In: O'Halloran, D., Green, C, Harley, M.
and Knill, J. (Eds), Geological and Landscape Conservation London, The
Geological Society, 87-91.
Glasser, N F. and Lewis, S G. 1994. A report on recent excavation and
conservation at Wolston Gravel Pit SSSI, Warwickshire. Quaternary Newsletter,
No. 74,1-9.
Gordon, J.E and Campbell, S. 1992. Conservation of glacial deposits in Great
Britain- a framework for assessment and protection of sites of special
scientific interest. Geomorphology, 6, 89-97.
Scottish Natural Heritage 1995. Scottish Natural Heritage Scottish Local
Authorities Handbook. Edinburgh, Scottish Natural Heritage
Scottish Natural Heritage, no date. Public Local Inquiries: Policy Guidance
Summary. Edinburgh, Scottish Natural Heritage.
Scottish Office 1994. Land for Mineral Working. National Planning Policy
Guideline NPPG 4. Edinburgh, Scottish Office Environment Department.
Earth Science Site Documentation Reports/Site Management Briefs provide
fundamental information on the interest of individual sites and explain the key
management objectives.
John E Gordon
Earth Science Branch
Research and Advisory Services Directorate
Scottish Natural Heritage
2 Anderson Place
EDINBURGH EH6 5NP
Tel: 0131-447 4784