OR/14/039 Model workflow

Mathers, S J, Terrington, R L, Waters, C N, and Thorpe S. 2014. The construction of a bedrock geology model for England and Wales. British Geological Survey Internal Report, OR/14/039.

A standard GSI3D workflow (Kessler & Mathers 2004; Kessler et al. 2009 ) was followed for the construction of the cross-sections.

Construction of cross-sections is performed in the GSI3D section window. This displays all the required information including the topography along the section, the bedrock geology at surface or rockhead, boreholes, intersections of crossing sections with the intercepts for individual units, surface traces from existing models displayed as raster backdrops. Structure contour maps are displayed in the GSI3D map window which is dynamically linked to the section window.

The geological units are normally constructed as baselines drawn in order going down the stratigraphic stack. The sections progressively colour up as the units are added.

Workspaces for section construction were prepared by the data management team including the alignments of all the revised, new and existing cross-sections. Existing sections were cut and terminated at regional boundaries utilising a specially developed tool for use in GSI3D. Each regional geologist(s) then completed construction of their allocated set of cross-sections and checked them for internal consistency. The interpretations where then reviewed along the boundaries of regions by pairs of geologists to produce a consistent agreed interpretation from which a master dataset was compiled.

The entire model was then reviewed for stratigraphic cohesion and consistency as follows, units to base of Palaeogene by Steve Mathers, Cretaceous by Peter Hopson, Jurassic by Mark Barron, and all older units by Colin Waters. The entire dataset was then signed off by Steve Mathers as project manager. The checking and sign-off are also recorded in the section database.

Geologists responsible for individual regions are listed in Table 1 and the regional areas are shown in Figure 14.

The revision of the England-Scotland border area was finally completed and the new GB3D_V2014 dataset was compiled.

Table 1 Regional geologists, for the areas in Figure 14

Region	Geologist(s)
Northern England	David Millward
Pennines & adjacent areas	Colin Waters
Eastern England	Jon Ford
Central England, and Bristol & Gloucester	Mark Barron
Welsh Borders	Oliver Wakefield
South West England	Richard Haslam
Wales	David Schofield, Phil Wilby
Hants Basin, and Weald	Peter Hopson
East Anglia, and London-Thames	Steve Mathers
Stratigraphic review	Colin Waters, Mark Barron, Peter Hopson, Steve Mathers
England-Scotland border review	Colin Waters, David Millward
QA and sign-off	Steve Mathers

Figure 14 Areas based on the BGS Regional Guide Series.

The revised model produced by this study for England and Wales is shown in Figure 15 and comprises part of the new GB3D_v2014 dataset. The dataset is freely available in a variety of formats from the BGS website at: https://www.bgs.ac.uk/research/ukgeology/nationalGeologicalModel/GB3D.html

Figure 15 The revised cross–section framework for England and Wales included in the GB3D_v2014 dataset.