BGS Seabed Geology 10k: Bristol Channel v2

The BGS Seabed Geology 10k: Bristol Channel v.2 digital map provides detailed and accurate characterisation of the seabed geology, based on seabed and shallow-subsurface data. This dataset incorporates three complementary map components (Substrate Geology, Structural Geology, and Geomorphology) presented at 1:10 000 scale, provided as discrete layers for viewing within a Geographic Information System (GIS). The bedrock geology is divided into 23 stratigraphical units: Aber Mawr Shale Formation (ABM); Avon Group (AVO); Bridport Sand Formation (BDS); Bishopston Mudstone Formation (BISHM); Charmouth Mudstone Formation (CHAM); Carboniferous Limestone Supergroup (CL); Devonian And Carboniferous Rocks (Undifferentiated) (DEVC); Devonian Rocks (Undifferentiated) (DEV); Dyrham Formation And Beacon Limestone Formation (Undifferentiated) (DYBN); Hangman Sandstone Formation (HASA); Inferior Oolite Group (INO); Lias Group (LI); Ludlow Rocks (Undifferentiated) (LUDL); Lavernock Shale Member (LVN); Milford Haven Subgroup (MIH); Mercia Mudstone Group (MMG); Pembroke Limestone Group (PEMB); Penarth Group (PNG); Porthkerry Member (PO); Skrinkle Sandstones Subgroup (SES); St Mary's Well Bay Member (STM); South Wales Lower Coal Measures Group (SWLCM); Triassic Rocks (Undifferentiated) (TRIA). The Lexicon code of the stratigraphical units is provided in parentheses, as defined in the ‘BGS Lexicon of Named Rock Units’. The superficial deposits mapped are comprised of only marine sediments (Marine Deposits Undifferentiated (MDU)) that were classified based on their grain size. The sediments are divided into Gravel (V): Sand (S); Mud (M); Sand and Gravel (XSV); Sand and Mud (XSM); and Gravel, Sand and Mud (XVSM). The RCS code of the stratigraphical units is provided in parentheses, as defined in the ‘BGS Rock Classification Scheme’.

Date (Creation): 2025-03-31

Citation identifier: http://data.bgs.ac.uk/id/dataHolding/13608435

Point of contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Distributor
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Point of contact
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Distributor
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Point of contact
British Geological Survey	Enquiries	not available	Distributor
British Geological Survey	Enquiries	not available	Point of contact

Maintenance and update frequency: As needed

GEMET - INSPIRE themes, version 1.0

Geology

BGS Thesaurus of Geosciences

Structural geology
UK Location (INSPIRE)
Bed rock
Surficial geology
BGS Data Products
Geomorphology
Sea floor
Mapping
Citable Data

dataCentre

Keywords

NERC_DDC

Access constraints: Other restrictions

Other constraints: licenceOGL

Other constraints: Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Use constraints: Other restrictions

Other constraints: 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.

Other constraints: Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Spatial representation type: Vector

Language: English

Topic category

Geoscientific information

Geographic identifier: BRISTOL CHANNEL [id=2001350]
British Geological Survey Gazetteer: Gazetteer of sea areas 2010 revision

End date: 2025-09

Unique resource identifier: WGS 84 (EPSG::4326)

Distribution format

Name	Version
ESRI Shapefile (.shp)

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Distributor

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Distributor

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	not available	Distributor

OnLine resource

Protocol	Linkage	Name
	https://www.bgs.ac.uk/datasets/bgs-seabed-geology/

OnLine resource

Protocol	Linkage	Name
	https://doi.org/10.5285/f7816c02-4e24-4563-988d-b4678115052a	Digital Object Identifier (DOI)

OnLine resource

Protocol	Linkage	Name
	https://mapapps2.bgs.ac.uk/geoindex_offshore/home.html	Offshore GeoIndex Homepage

Hierarchy level: Dataset

Other: dataset

Conformance result

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

Date (Publication): 2011

Explanation: See the referenced specification

Pass: No

Conformance result

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

Date (Publication): 2010-12-08

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

Pass: No

Statement: The delineation and classification of the geological substrate units were based primarily on what can be observed and interpreted from the high-resolution (2m) multibeam echo-sounder (MBES) bathymetry data collected during the Civil Hydrography Programme (CHP) surveys managed by the Maritime and Coastguard Agency (MCA). MBES backscatter, physical samples (e.g. grabs, cores, and boreholes) and previous geological mapping were also used to further inform the geological interpretation. In 2019, G. Carter, R. Ellen, J. Everest, R. Kendall and E. Phillips mapped the area covered by the HI1327, HI1326 and HI1325 MBES MCA surveys, with ESRI ArcGIS using the BGS SIGMA Desktop application. The geological linework was done at a scale ranging from 1:5000 to 1:7000, to ensure smooth linework when the dataset is viewed at a scale of 1:10000. Bedrock and superficial deposits were mapped into two independent SIGMA layers and later merged to create the Seabed Substrate layer included in this dataset. Additional attribute fields were added to the layers, in particular to the geomorphology, to complement the information captured automatically by the SIGMA. The methodology used is described in more detail in the user guide for this dataset (OR/25/041). A second phase of mapping was undertaken by R. Kendall and H. Burke in 2024 with further HI areas (HI1375, HI1449, HI1501, HI1502, HI1576, HI1662), expanding the coverage of the geological mapping area.