OR/16/046 About the BGS geology: 50k v8 dataset

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Armstrong, R, Daley, D, Lawley, R, Myers, A and Smith, A. 2016. User guide for the BGS geology: 50k dataset (v8). British Geological Survey Internal Report, OR/16/046.

Background[edit]

The British Geological Survey provides digital geological maps as part of its ‘BGS Geology’ product line. Since its launch in 1998, BGS Geology (formerly known as DiGMapGB) has produced several versions of the 1:50 000 scale data and this guide relates to Version 8.24 released in 2016. Each version has included new and replacement content that reflects the ongoing work of the Survey to extend and improve its geological map coverage.

Who might require this data[edit]

Geological maps are the foundation for many types of work. They are of potential use to a wide range of customers with economic interests in planning and development, oil and gas reserves, water and mineral resources, waste disposal sites, utilities, transport, geohazards and property insurance; as well as more academic aspects such as the Earth’s geological history, its fossils, and its landscape development.

These datasets are available as vector data (in a variety of formats), they are structured into themes primarily for use in geographical information systems (GIS), where they can be integrated with other types of spatial data for analysis and problem solving in many earth-science related issues.

What the data show[edit]

The BGS Geology: 50k data provide a digital representation of the geology previously shown on the map face of the published 1:50 000 scale paper maps.

The data are arranged into four geological themes:

  1. Bedrock (e.g. rocks and deposits laid down prior to 2.588 million years ago — but including the Crag Group)
  2. Superficial (e.g. deposits laid down during the Quaternary Period)
  3. Mass Movement (e.g. areas of landslide)
  4. Artificial (e.g. areas of artificially modified ground)

And an additional component for:

  1. Linear features (e.g faults)

Each theme is provided as a set of digital files that make up a GIS data layer. The Bedrock, Superficial, Mass movement and Artificial layers represent geological units as a series of polygons (with text attributes). The linear features layer represents features that are either non-polygonal (such as fault planes or geological lineaments and landforms) or features that are too small to be defined as polygons in the other layers (such as thin coal seams and fossil horizons).

Attribute information is provided for every record in each layer in tabular form, with each field of attribution specific to the layer and the characteristic of the feature being described. For example, attribution may include the age of a geological unit, or its lithology. Additional attribution is provided for in links to further resources (such as hyperlinks to BGS webpages) and also metadata about the dataset (e.g. the scale, version or release date of the data). Information about the types of geological attribution available in BGS Geology: 50k is provided in the field-descriptions section below. Users are advised to familiarise themselves with the data structure and the underpinning geological concepts as outlined in Table 1, Table 2, Table 3, Table 4 and Appendix 2.

How to view the data[edit]

The vector files of the BGS geology: 50k v8 dataset can only be viewed in a Geographic Information System (GIS) such as ArcMap, MapInfo or QGIS. GIS software is available from many vendors; free-to-use (open source) variants are available online. Typically, BGS supplies digital vector data in the ESRI ‘shape’ format (which is widely used), but vector data can also be provided in a range of other GIS and CAD formats (contact BGS for further details).

Simplified versions of the BGS Geology: 50k Bedrock, Linear and Superficial themes are also available to view (for free) via the BGS OpenGeoscience pages at: www.bgs.ac.uk/opengeoscience/home.htmlwhere there are links to an online digital map viewer.

Similar data can also be viewed using the ‘iGeology’ app for iPhone/iPad and Android, available via www.bgs.ac.uk/data/apps/home.html