The Dieppe Basin and adjacent areas
Seafloor mapping and seismic surveys, from the 1950s onwards, discovered that Paleogene sediments are present over a wide area in a wide shallow synclinal structure in the eastern English Channel, extending almost to the French coast. This subsea syncline was named the Dieppe Basin (Roberts 1989), and was originally believed to be separated from the Hampshire Basin. Further subsea investigations showed that there is a continuous Paleogene outcrop between this area and the Hampshire Basin (Fig. 42) (Balson in Hamblin et al. 1992, fig. 51). When this continuity was demonstrated, the whole structure was named the Hampshire-Dieppe Basin (Curry & Smith 1975), but it is useful to maintain both terms for descriptive purposes. Small onshore Paleogene outliers, including the Newhaven Outlier on the East Sussex coast in southern England (Figs 42, 158 & 160), and on and near the coast of NW France (including the ‘Dieppe outliers’), are now recognized to be outliers of the Dieppe Basin.