Annex C

(informative)

Sources of information

C.1 Ordnance Survey

As Great Britain's national mapping authority, Ordnance Survey produces a wide range of products documenting the physical and social geography of Great Britain, including historical maps. For current information, see the Ordnance Survey website.¹⁸⁾

C.2 Geological survey, soil survey maps and reports

C.2.1 Geological maps and reports

C.2.1.1 General

The British Geological Survey (BGS) is the national repository for geoscience data in the UK. It is the custodian of an extensive collection of digital data, maps, records and materials relating to the geology of the UK, its continental shelf and many countries overseas. Digital indexes to the collections have been established and selective geographical searches of data availability are carried out using a GIS-based information retrieval system. The BGS operates a central enquiry desk at its Keyworth office. Enquiries dealing with particular localities can be processed online through the Geolndex or GeoReports Service or can be submitted by email or post, accompanied by a marked-up copy of a map or by eight-figure national grid references defining the area in question.

Local libraries can also provide a source of geological information for the locality. The Geological Society at Burlington House, London has an extensive library for the use of its members and bona fide researchers.

C.2.1.2 Maps

The British Geological Survey produces geological and thematic maps at scales between 1:10 000 and 1:1 million scale covering both onshore and offshore areas. The 1:10 000 scale series of geological maps are available for large areas of the country, particularly urban areas. Geological maps at this scale are published digitally (DiGMapGB-10) with a print on demand option for those requiring a paper copy. The geology presented in these maps is structured in five themes.

• a) Bedrock geology is the main mass of rocks forming the Earth and is present everywhere, whether exposed at the surface in outcrops or concealed beneath artificial ground, mass movement deposits, superficial deposits or water.
• b) Artificial ground where the ground surface has been significantly modified by human activity.
• c) Linear features related primarily to the bedrock theme, being either an intrinsic part of it (e.g. a mineral vein) or affecting it (e.g. a fault).
• d) Mass movement deposits are masses of rock, earth or debris that have moved downslope under gravity and are generally known as landslides.
• e) Superficial deposits are the youngest geological deposits formed during the most recent period of geological time, the Quaternary, which extends back about 2,6 million years from the present.

1:50 000 scale geological maps provide onshore national coverage and are available digitally (DiGMapGB-50) as an online view service on the BGS website, BGS mobile website and as apps for various devices; partial national coverage of litho-printed maps at this scale or a site-specific map report containing digital map extracts as part of the GeoReport service. The geology presented in these maps has the same five themes as the 1:10 000 scale map series.

Onshore digital geological maps are available at a scale of 1:625 000; the themes are bedrock geology and superficial (with mass movement, dykes and linear (fault) features). These are available for free viewing on (and download from) the BGS website. Litho-printed 1:625 000 scale geological maps are also available for purchase.

Offshore digital geological maps are available at a scale of 1:250 000 as DigRock250 and DigSBS250 providing details of the solid geology and seabed sediments. Litho-printed versions are available at the same scale.

The British Geological Survey produces a range of 1:50 000 scale digital thematic maps of Great Britain (see Table C.1) including:

• a) the DiGMapGB-plus Engineering Properties dataset (including strength and excavatability);
• b) the Superficial Deposit thickness digital model showing the modelled depth to the bedrock surface;
• c) the GeoSure dataset provides information about potential ground movements or subsidence including:
  • 1) collapsible deposits;
  • 2) compressible ground;
  • 3) landslides;
  • 4) running sand;
  • 5) soils with shrink swell properties; and
  • 6) soluble rocks.
• d) the mining hazard (not including coal) dataset provides essential information to developers building in areas of former shallow mining for resources other than coal;
• e) the radon potential dataset which is the definitive map for radon affected areas in Great Britain;
• f) geological indicators of flood potential such as floodplains and coastal plains and, therefore, those areas at greater risk of flooding;
• g) susceptibility to groundwater flooding;
• h) the infiltration SuDS (Sustainable urban Drainage Systems) map provides invaluable information to those involved in designing sustainable urban drainage systems as part of a development.

A range of applied geology maps covering new town and development areas, and engineering geology maps associated with special local or regional studies are available. These maps normally accompany open-file reports but can also be purchased separately. The BGS has also published hydrogeological maps of the whole of the UK and more detailed maps of major aquifer units, and geophysical maps of gravity and aeromagnetic anomalies covering the British Isles and its continental shelf.

C.2.1.3 Models, virtual borehole and virtual cross-section viewers

The BGS has developed a series of new products and web-based tools to assist in the understanding of geology in three or more dimensions. These products include geological modelling systems that produce three- and four-dimensional geological models, some of which are available for viewing on the BGS website and others that can be licensed.

Tools have been developed and are published on the BGS website that allow a user to "drill" virtual boreholes or draw virtual cross-sections through a geological model. This service is only available for selected areas at present but is intended to become more widespread over time.

NOTE The user needs to understand the scale and uncertainties of these products.

C.2.1.4 Reports

The BGS has produced a number of published and unpublished report series describing aspects of geology. These include:

• British Regional Geology Guides: a series of 20 handbooks describing the geology of individual regions of the United Kingdom;
• Offshore regional report: a series of reports describing the offshore geology of the United Kingdom which has been published to complement the British Regional Geology Guides;
• Memoirs: the 1:50 000 and 1:63 360 geological map series were formally accompanied by a series of explanatory sheet memoirs. They include coalfield and economic memoirs for selected areas of the country. The memoir series has been published over many years and the geological interpretations in the older editions might have been changed. Copies of out of print memoirs can be obtained from the BGS's Library at Keyworth, Nottingham;
• Reports: a series of reports, variously known as Technical Reports, Open File Reports, Commissioned Reports, etc., contain a wealth of detailed geological and related information. A number of these were created in parallel to the mapping of 1:10 000 scale geological map sheets and are often identified as "Geological notes and local details". The BGS has also published a series of engineering geology studies of bedrock formations such as the Gault Formation, Lias Group, etc. Some of these publications are freely available through the online NERC (Natural Environment Research Council) Open Research Archive (NORA).¹⁹⁾
• GeoReports: a GeoReport is site specific, as requested by the customer. It provides cost-effective access to unique sources of published and unpublished geological data, combined with expert advice from BGS scientists who know about the local area. The reports are either automatically generated from the British Geological Survey databases or are bespoke. Bespoke reports describe the various layers of man-made and natural geology expected to be underlying a site; it also includes geological map extracts and a list of the available data sources. They can be customized with additional modules such as Engineering Geological, Hydrogeology and Drilling Considerations.

C.2.1.5 Borehole records

The BGS has scanned over a million borehole records and made them available through a free Borehole Record Viewer. This offers direct, online access to the onshore borehole collection held by the National Geoscience Data Centre comprising boreholes drilled for a range of purposes including:

• ground investigation, for example for highways;
• water abstraction;
• ground source heat pumps;
• mineral exploration;
• mining;
• oil and gas exploration; and
• geological research.

C.2.1.6 Hydrogeological information

A BGS hydrogeological database, called WellMaster, holds details of many thousands of water boreholes and wells. The database includes information on geology, well construction, water levels and yields; water quality has also been digitized for the majority of water boreholes, if the information is available. All this information is available via the BGS website.

C.2.1.7 Library services

The BGS library at Keyworth offers a range of literature search services, commercial desk-top study facilities and other related services. Library facilities are also available at the BGS Edinburgh office.

C.2.1.8 National Geoscience Data Centre and National Geological Repository

The most comprehensive collection of information about subsurfaces is at the National Geoscience Data Centre. Part of the BGS, the National Geoscience Data Centre and the National Geological Repository comprises data gathered or generated by the BGS or its precursors, in addition to data provided by numerous external organizations.

The National Geoscience Data Centre manages digital data storage whilst the National Geological Repository holds over 500 km of drill core and 4,5 million core samples. Together they hold tens of millions of items of data and documents, including about 90 000 ground investigations.

The large majority of this collection is available for public consultation.

C.2.1.9 Enquiries service

The British Geological Survey runs a central enquires desk.