OR/14/050 Model workflow

Monaghan, A A. 2014. Model metadata report for BGS - DECC shale study model, central and eastern Midland Valley of Scotland. British Geological Survey Internal Report, OR/14/050.

The GOCAD^® structural workflow manager (GOCAD^® version 2009.4) was used as standard to create a fault model and faulted horizon surfaces.

During the faulted horizon modelling, data points within a tolerance of 200 m of faults were excluded. Some additional manual exclusion of seismic pick data points was made close to faults where the faults had a more complex geometry than the planar structures modelled.

Manual editing of fault-horizon contacts was necessary in some cases to create a more consistent throw. Horizon crossovers were also removed manually. Control nodes were inserted at borehole/well data points (see Seismic data). Edits were also made such that horizon surfaces were:

• deeper than boreholes proving the modelled stratigraphic units but not reaching the base (e.g. total depth (TD) within LSC)
• the base Limestone Coal Formation was deeper than The Coal Authority deep coal mining dataset (see Mine plan data)
• the base West Lothian Oil-Shale Formation was deeper than contours on the Burdiehouse Limestone given in Mitchell and Mykura (1962)