Drift-filled hollows (rock-head depressions) which occur beneath Lower Floodplain deposits of Ipswichian to Recent age in central London can be related to shallow buried ‘channels’ (elongate closed hollows). Twenty-six depressions are represented on a map of the channels and other buried features and are individually described. Most of these are grouped in the South Lambeth–Battersea–Westminister–Southwark area and are formed in the surface of the London Clay. They often appear to coincide with stream junctions in the Recent drainage pattern. Under-drainage may occur in some depressions through contact with underlying granular Lower Tertiary sediments. In some cases, these deposits appear to have risen above the adjacent levels as diapiric features, possibly at the time when deepening of the hollows occurred.
- © The Geological Society, London 1979