Identification

Title

Digital Geological Map Data of Great Britain - 25k (DiGMapGB-25) version 2

Abstract

Data identifying landscape areas (shown as polygons) attributed with geological names. The scale of the data is 1:25 000 scale. Onshore coverage is partial and BGS has no intention to create a national coverage at this scale. Areas covered are essentially special areas of 'classic' geology and include Llandovery (central Wales), Coniston (Lake District) and Cuillan Hills (Isle of Skye). Data are supplied as five themes: bedrock, superficial deposits, mass movement, artificial ground and linear features. Bedrock geology describes the main mass of solid rocks forming the earth's crust. Bedrock is present everywhere, whether exposed at surface in outcrops or concealed beneath superficial deposits or water bodies. The bedrock theme defines landscape areas (shown as polygons) attributed with geological names. Geological names are based on the lithostratigraphic or lithodemic hierarchy. The lithostratigraphic scheme arranges rock bodies into units based on rock-type and geological time of formation. Where rock-types do not fit into the lithostratigraphic scheme, for example intrusive, deformed rocks subjected to heat and pressure resulting in new or changed rock types; then their classification is based on their rock-type or lithological composition. This assesses visible features such as texture, structure, mineralogy. Superficial deposits are younger geological deposits formed during the most recent geological time; the Quaternary. These deposits rest on older rocks or deposits referred to as bedrock. The superficial deposits theme defines landscape areas (shown as polygons) attributed with a geological name and their deposit-type or lithological composition. Mass movement describes areas where deposits have moved down slope under gravity to form landslips. These landslips can affect bedrock, superficial or artificial ground. Mass movement deposits are described in the BGS Rock Classification Scheme Volume 4. However the data also includes foundered strata, where ground has collapsed due to subsidence (this is not described in the Rock Classification Scheme). Caution should be exercised with this data; whilst mass movement events are recorded in this layer, due to the dynamic nature of occurrence significant changes may have occurred since the data was released, as such it should be viewed as a snapshot in time (data should be regarded as at 2008). Artificial (man-made) theme (shown as polygons) indicates areas where the ground surface has been significantly modified by human activity. Whilst artificial ground may not be considered as part of the 'real geology' of bedrock and superficial deposits it does affect them. Artificial ground impacts on the near surface ground conditions which are important to human activities and economic development. Due to the constantly changing nature of land use and re-use/redevelopment, caution must be exercised when using this data as it represents a snapshot in time rather than an evolving picture hence the data may become dated very rapidly. Linear features (shown as polylines) represent geological structural features e.g. faults, folds or landforms e.g. buried channels, glacial drainage channels at the ground or bedrock surface (beneath superficial deposits). Linear features are associated most closely with the bedrock theme either as an intrinsic part of it for example marine bands or affecting it in the case of faults. However landform elements are associated with both bedrock and superficial deposits. All five data themes are available in vector format (containing the geometry of each feature linked to a database record describing their attributes) as ESRI shapefiles and are available under BGS data licence. Another batch of tiles was added to the data in 2012 to bring the total to 167 for this version 2 release.

Resource type

dataset

Resource locator

https://www.bgs.ac.uk/datasets/bgs-geology/

name: Home page for BGS Geology: onshore digital geological map of Great Britain data

function: information

Unique resource identifier

code

http://data.bgs.ac.uk/id/dataHolding/13603060

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

originating controlled vocabulary

title

GEMET - INSPIRE themes

reference date

date type

publication

effective date

2008-06-01

Keyword set

keyword value

Data

GIS

Digital maps

Geology

Geological maps

originating controlled vocabulary

title

BGS Thesaurus of Geosciences

reference date

date type

revision

effective date

2011

Keyword set

keyword value

NERC_DDC

Geographic location

West bounding longitude

-8.6500

East bounding longitude

1.7800

North bounding latitude

60.8600

South bounding latitude

49.7700

Extent

Extent group

authority code

title

ISO 3166_2

reference date

date type

revision

effective date

2009

code identifying the extent

GBN

Extent group

authority code

title

British Geological Survey Gazetteer: Geographical hierarchy from Geosaurus

reference date

date type

creation

effective date

1979

code identifying the extent

GREAT BRITAIN [id=139600]

Temporal reference

Temporal extent

Begin position

End position

2012

Dataset reference date

date type

creation

effective date

2008

date type

publication

effective date

2012

Frequency of update

notPlanned

Quality and validity

Lineage

Each DiGMapGB-25 digital tile is typically based on the latest 1:25 000 scale geological map. These geological maps are compiled on contemporary Ordnance Survey National Grid topographical base maps at 1:25 000 scale. Most are based on more detailed 1:10 000 or 1:10 560 (six-inch to one-mile) scale geological maps, and as a consequence they have not been digitised to create DiGMapGB-25 tiles as the source 1:10 000 or 1:10 560 maps could be used to create DiGMapGB-10 data. There are about 52 tiles of 1:25 000 scale data produced by ‘rapid mapping’ surveys in parts of Central Wales, the Scottish Highlands and the Southern Uplands. These were carried out at 1:25 000 scale rather than the normal 1:10 000 scale in order to expedite completion of the 1:50 000 scale map series. The data has been digitally captured from paper record, originally using Bentley MicroStation and latterly ESRI ArcGIS software. Post capture processing has occurred to combine geometry and attribution from existing BGS data resources. Changes may have been made to the geological interpretation but major revisions to the geological lines have generally been avoided. The geological nomenclature has been reviewed and revised, as far as reasonably possible, to conform to the most up-to-date accepted usage; usually this will also agree with the DiGMapGB-50 dataset. The lithology of bedrock units and superficial deposits recorded for DiGMapGB-25 may differ slightly from those given for the same area in DiGMapGB-50, but they should generally fall within the description used for the DiGMapGB-50 data. 34 The change from Version 1 to Version 2 reflected a major change in the coding of polygons and linear features from attribute level 11 to 18. Another batch of tiles was added to the data in 2012 to bring the total released to 167. The LEX_ROCK codes were replaced by LEX_RCS codes with the lithology based on the hierarchical BGS Rock Classification Scheme. The superseded LEX_ROCK field was retained, to link back to previous versions of DiGMapGB, but demoted in the attribute list.

Conformity

Conformity report

specification

title

INSPIRE Implementing rules laying down technical arrangements for the interoperability and harmonisation of Geology

reference date

date type

publication

effective date

2011

degree

false

explanation

See the referenced specification

Conformity report

specification

title

Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services

reference date

date type

publication

effective date

2010-12-08

degree

false

explanation

See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF

Data format

name of format

ESRI shapefiles

version of format

Constraints related to access and use

Constraint set

Limitations on public access

Constraint set

Limitations on public access

The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.

Responsible organisations

Responsible party

organisation name

British Geological Survey

full postal address

Environmental Science Centre, Nicker Hill, Keyworth

NOTTINGHAM

NG12 5GG

United Kingdom

telephone number

0115 936 3143

facsimile number

0115 936 3276

email address

enquiries@bgs.ac.uk

responsible party role

distributor

Responsible party

organisation name

British Geological Survey

full postal address

Environmental Science Centre, Nicker Hill, Keyworth

NOTTINGHAM

NG12 5GG

United Kingdom

telephone number

0115 936 3143

facsimile number

0115 936 3276

email address

enquiries@bgs.ac.uk

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

organisation name

British Geological Survey

full postal address

Environmental Science Centre,Keyworth

NOTTINGHAM

NG12 5GG

United Kingdom

telephone number

+44 115 936 3100

email address

enquiries@bgs.ac.uk

responsible party role

pointOfContact

Metadata date

2023-01-23

Metadata language

eng