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Our maps and data

Geology Digimap gives access to the main onshore and offshore geology products from British Geological Survey (BGS), along with some groundwater and rock information data.

Data is covered by either the Geology Digimap educational license or the BGS OpenGeoscience licence.

Onshore geology

BGS provides digital geological maps of Great Britain based on the different series of published BGS geological maps. The larger-scale maps provide detail for site-specific use; the medium- to small-scale maps provide national coverage. Ongoing revisions from our survey activities are updated on a regular basis. Digital data is available at four key scales:

1:10 000

This digital geological data is based on BGS’s highest-resolution survey mapping. Many urban centres and transport routes are covered by this dataset. Lithostratigraphic nomenclature is updated to current usage.

1:50 000

This generalised digital geological data is based on BGS’s 1:50 000 and 1:63 360-scale maps. Covering almost all of Great Britain, it provides a detailed local to regional description of geology and underpins many of BGS’ national map services and products. Lithostratigraphic nomenclature is updated to current usage.

1:250 000

This generalised digital geological data is based on 1:250 000-scale, bedrock-only maps. Data and lithostratigraphic re-classifications are derived from maps published between 1977 and 1993.

1:625 000

This generalised digital geological dataset is based on the published ‘poster’ maps of the UK from BGS. This dataset covers all of Great Britain and includes additional map data from Northern Ireland. It provides an excellent national overview of the UK’s geology and is commonly used as a teaching resource.

Soil Parent Material

Soils are the result of weathering processes that occur on the Earth’s surface where the atmosphere meets the geosphere and hydrosphere. We live in this ‘critical zone’, relying on our soils to grow our food and sustain the biodiversity and health of our environment.

A ‘parent material’ is a soil-science name for a weathered rock or deposit from and within which a soil has formed. In the UK, parent materials provide the basic foundations and building blocks of the soil, influencing their texture, structure, drainage and chemistry.

Superficial Thickness

Superficial deposits are the youngest geological formations (less than 2.6 million years old). They are largely unconsolidated and cover much of the bedrock of Britain. They generally include sediments deposited during the Pleistocene (Quaternary) glacial episodes and subsequent Holocene rivers and coastal systems; superficial deposits also include modern, artificial deposits such as mining spoil and road embankments.

The superficial thickness model shows the depth of the bedrock surface and this information is critical in a number of areas of work. For example, in civil engineering, it is used in the evaluation of groundwater resources and possible water pollution and in the prediction of surface hazards such as landslides and the collapse of underlying rocks.

Offshore geology

1:250 000-scale offshore geological maps are available digitally as two themes: offshore bedrock geology and seabed sediments.

Marine bedrock methodology - the overlying column of sea water imposes major limitations offshore that make it impossible to use normal, onshore, geological mapping techniques. However, other techniques, such as ship-board geophysical surveys, can be used that allow geological interpretations using evidence not normally available onshore.

The offshore bedrock geology theme is essentially the same as that mapped onshore, but it is usually much less detailed. Onshore, a lithostratigraphical nomenclature is used with rocks routinely mapped at formation, member and bed level. Offshore, this is often impossible and rocks are commonly referred to by age. Where it is possible, mapping is usually only to group or formation level at best and even these may not be differentiated into individual units, but shown only as part of a package of units.

Rock Information

Two products are available in this category; the Lexicon of Named Rock Units and the Onshore Borehole Index.

Lexicon of Named Rock Units

The BGS Lexicon of Named Rock Units provides definitions of the lithostratigraphic, lithodemic and lithomorphogenetic geological units of the UK and its continental shelf. The lexicon focuses mainly on geological units of member, formation and group rank (and equivalent) but it also includes information on some units of lesser rank, notably economically important coal seams and laterally extensive marine bands. It includes superficial and bedrock units, plus synonyms and other names that are not currently recognised by the BGS or regarded as obsolete.

Onshore Borehole Index

The Single Onshore Borehole Index (SOBI) is an index of over one million records of boreholes, shafts and wells from all forms of drilling and site investigation work held by the BGS.

The collection covers onshore and near-shore boreholes from Great Britain dating back to at least 1790 and ranging from one to several thousand metres deep. Each year thousands of new records are added.

Groundwater

Three datasets are available:

Geological Indicators of Flooding

The geological indicators of flooding dataset is a digital map based on the BGS Digital Geological Map of Great Britain at 1:50 000 scale (BGS Geology 50K). Coverage includes England, Wales and Scotland. It characterises superficial deposits on BGS Geology 50K in terms of their likely susceptibility to flooding, either from coastal inundation or fluvial (inland) water flow.

Permeability Indices

‘Permeability’ refers to whether and how water can flow through a rock. Permeability data is often used in studies of groundwater and in particular during investigations of pollution or aquifer contamination. BGS have prepared permeability information based on the 1:50 000-scale digital geological map of Great Britain (BGS Geology 50K).

1:625000 Hydrogeology

The hydrogeological map indicates aquifer potential in generalised terms using a threefold division of geological formations:

  • those in which intergranular flow in the saturated zone is dominant
  • those in which flow is controlled by fissures or discontinuities
  • less permeable formations including aquifers concealed at depth beneath covering layers