OR/16/034 Model workflow

Barron, A J M. 2016. Metadata report for GSI3D cross sections along the HS2 route in Area 9 (Birmingham spur). British Geological Survey Open Report, OR/16/034.

The standard GSI3D modelling workflow was followed for this project to the point where cross-sections are cross-correlated. GSI3D software utilises a range of data such as boreholes, digital terrain models (DTM) and geological linework to enable the geologist to construct a series of interlocking cross-sections. Borehole data is represented in GSI3D by two proprietary files: a borehole identification file (.bid) that contains ‘index’-level information including location and start-heights; a borehole log file (.blg) that contains the borehole interpretation. Constructing cross-sections is intuitive and flexible, combining borehole and outcrop data with the geologist’s experience to refine the interpretation.

In order to control the relative vertical ordering of the units, a generalised vertical section file (.gvs) is established. A proprietary legend file (.gleg) is created to control symbolisation of the cross-sections. The modeller can view all the correlated sections in 3D and iteratively return to any cross-section to make amendments or add further cross-sections to refine the model. This process is a standard methodology within BGS for modelling Quaternary and simple bedrock horizons and is fully documented in Kessler et al. (2009).