NNW-SSE cross-section through the Rémarde Anticline and the Beauce trough (location Fig. 9) showing the geometry of the base of Fontainebleau Sand Formation and the base of the Fontainebleau quartzite. The main altitude variations related to the La Rémarde Anticline and Beauce trough are similar for both curves – even if considering an uncertainty of ±10 m (grey area) – indicating that both surfaces are folded together. Curves merge in the eastern part as the thickness of the Fontainebleau sands decrease until complete disappearance of the formation (Rupelian basin border).