Return to Maps Page From the 'Geology of the Country around Banbury and Edge Hill.' It shows that the ironstone strata was in the region of 20ft -25ft. It turned out to be a lot less on the first section of the escarpment, probably due to erosion of the top levels in geological time. Next Map A typical quarry face near Hornton, not on the line of the EHLR.  This shows a face about 25 ft high, as expected from the above map.  However, the EHLR  cuttings showed about 10 ft of ironstone, over a silty clay subsoil. This led to massive erosion. The cut faces could not stand vertically. The levels of the track should have been set higher, to be at the base of the ironstone strata.