Geological Survey of Great Britain (England and Wales) Great Britain. Ordnance Survey. Sheet 346 drift. Geological Survey of Great Britain. North Decimal Degree 50.4667. South Decimal Degree 50.3000. East Decimal Degree -4.9333. West Decimal Degree -5.3333. Relief shown by contour interval and spot heights.Transverse Mercator projection. National grid system. Depth is shown by contour interval. "Original Geological Survey on the one-inch scale, by Sir H. T. De la Beche. Published on Sheets 30 & 31 Old Series. Geological Survey on the six-inch scale, by Clement Reid, F.R.S. et al.".