OR/13/001 Model datasets

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GVS & GLEG files
These files were assembled in a combination of Notepad, Wordpad and Excel and iterated as the model expanded and new units were encountered. The current files are Regional_V9.gvs and Regional_v10.gleg. The model colour schema is shown below in Figure 3.

Figure 3    The colour schema used.

Boreholes
Borehole records examined as indicated below. Many start heights were revised in SOBI and some grid references corrected by the data management team. Closely clustered sets of boreholes were not all coded but the deepest and most representative were included; any significant local variation in sequence was also recorded by coding. Entries were all made directly into the corporate Boge data entry application with sjma as the interpreter in all cases.

TL92 borehole coding TL92NW 1-43 TL92NE 1-388, TL92SW 1-125 and TL92SE 1-388 were examined by S J Mathers in 2011.
TM01 borehole coding TM01NW1-7, TM01NE1-96, TM01SW 1-6 and TM01SE 1-2 were examined by S J Mathers in 2011.
TM11 borehole coding TM11NW1-8, TM11NE1-7, TM11SW 1-5, andTM11SE1-9 were examined by S J Mathers in 2011.
TM21 borehole coding TM21NW1 was examined by S J Mathers in 2011.
TM02 borehole coding TM02NW1-219, TM02NE1-139, TM02SW1-99 and TM02SE1-118 were examined by S J Mathers in 2011.
TM12 borehole coding TM12NW1-49, TM12NE1-30, TM12SW1-48 and TM12SE1-21 were examined by S J Mathers in 2011.
TM22borehole coding TM22NW1-7, TM22SW1-30 and TM22SE1-2 were examined by S J Mathers in 2011.

Rasters
Geo referenced raster backdrops taken from Figure 14 of the Braintree memoir (Ellison & Lake 1986 [1]) have been used to align and construct portions of sections Marks Tey_Section A, B and C.

Geological Linework
Modern 1:10 000 scale digital linework was used throughout the TM sheets. Sheets TM 01 , 11, 21, 02, 12, and 22 were surveyed by S J Mathers in 2005-8 together with revisions of parts of TL92 NE and SE as far west as easting 98. Farther west the 1:10 560 survey data for the Braintree 1:50 000 mapsheet (BGS 1982[2], Ellison & Lake, 1986[1]) were utilised for the TL92 tile and considerably revised by the modelling. This has produced new linework for the whole of TL92 that should now be used to update the master 10K linework for both the Quaternary and bedrock themes.

DTM
Each 25K model tile was produced individually using a CEH or Nextmap DTM mainly with a 50 m grid size. The merged model was initially capped by a CEH 100 m dtm, this was then replaced by a Nextmap 100 m and then the final models is capped but not snapped to a trimmed BGS Bald Earth dtm (with a 50 m resolution) produced by combining elements of the OS Panorama dataset and the Nextmap 5M dataset. The data was extracted using the wizard provided within the software.The current file name Bald Earth_2 [TIN].

References[edit]

  1. 1.0 1.1 ELLISON, R A, and LAKE, R D. 1986. Geology of the country around Braintree Memoir of the British Geological Survey, Sheet 223.
  2. BGS. 1982. Braintree 1:50 000 Mapsheet 223 Solid & Drift Geology.