The rock floor of the English Channel and its significance for the interpretation of marine unconformities

The English Channel is for the most part an area of erosion, not of permanent deposition. In an area extending from beyond the Scillies in the west as far as Ostend in the east there is solid rock at or near the seafloor almost everywhere. The overlying superficial sediment is coarse-grained and contains abundant derived fossils—a typical basement bed. The rock floor is suffering continuing erosion, but the materials so released are not accumulating locally, but are being carried towards the continental slope or into the North Sea. The situation appears to be a stable one, with a life expectancy of perhaps 1 m.y. The implications of this large area of marine non-deposition are discussed, using the examples of other unconformities in the earlier history of the Channel region.