OR/15/074 Modelled volume, purpose and scale

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Ambrose, K. 2015. GSI3D model metadata report for HS2 Area 8 (Drayton Bassett to Rugeley). British Geological Survey. (OR/15/074).

The model purpose was to model the bedrock, superficial and artificial ground following the proposed High Speed Rail link between London and Birmingham (HS2). The model area covers a 25 km section of the route from Drayton Bassett in the south to Rugeley in Staffordshire in the north with a 5 km buffer (Figure 1). This is one of an initial group of nine models along the proposed route. Area 7 to the south was modelled by Keith Ambrose; the area to the north has not yet been modelled. The model is suitable for use at scales between 1:100 000 and 1:10 000 to a depth of 30 m below Ordnance Datum (OD).

The geology of the area is described in Powell et al., (2000), Barrow et al., (1919)[1] (northern part) and Bridge et al., (1998) (south east corner). The bedrock geology of this section of the route comprises Carboniferous and Triassic age strata, which are overlain by superficial deposits of glacigenic and fluvial origin. Artificial deposits, such as gravel pits and embankments are also modelled. Prior to the modelling work an assessment of the quality and availability of digital geological linework and existing 3D models of the whole HS2 route between London and Birmingham was undertaken (Barron et al., 2012[2]). As a consequence of this review, most of the geological mapping of this sector was deemed to be adequate, dating from a recent revision undertaken in the 2000s to geological sheet 154 (Lichfield). This 3D model is based on geological linework from existing 1:10 000 and 1:50 000 scale DiGMapGB data, with new data added for the Lichfield sheet mapping. The northern most part of Area 8 is on geological sheet 140 (Burton upon Trent), which dates from the late 1940s. Modifications have been made in the northernmost part of the model, with new bedrock and superficial linework added, mainly in relation to the artificial deposits. However, some errors were also noted in the recently mapped areas.

File:OR15074fig1.jpg
Figure 1    Location of the Area 8 model (outlined in black), proposed route (red line) and National Grid 1:10 000 map sheet areas (grey).

References

  1. Barrow, G, Gibson, W, Cantrill, T C, Dixon, E E L, and Cunnington, C H. 1919. The geology of the country around Lichfield. Memoir of the Geological Survey of Great Britain, Sheet 154 (England and Wales).
  2. Barron, A J M, Thompson, J, and Powell, J H. 2012. Assessment of BGS maps and 3D models along the proposed HS2 route. British Geological Survey Internal Report IR/12/043.