Table 3.

Summary of the landslide sequence observed in the study area controlled by the presence or absence of the Marlstone Rock Formation lithological bench midway up the escarpment slope.

Marlstone Rock Formation lithological bench
GeologyPresentAbsent
Inferior OoliteCambering at the edge of the Inferior Oolite plateau.
Whitby Mudstone FormationLarge-scale rotational landslides forming flat and back-tilted benches.
Marlstone Rock FormationAccumulation of landslide material on the lithological bench.Landslide development on main escarpment face or within small inter-spur valleys formed between lithological benches.
Mudslide source zones form bowl-shaped depressions and backscarps at the edge of the lithological bench.
Dryham FormationLobate mudslides emanate from lithological bench above and accumulate at the base of the Dryham Formation scarp slope.Continuation of landsliding in form of complex sequence of successive rotational and translational landslides and mudslides.
Occasional large rotational landslides in Dryham Formation (Colliers Knap).
Charmouth Mudstone FormationAccumulation of irregular and lobate mudslides.Large apron of irregular and lobate mudslide deposits.