Description

The Folkestone Warren landslide is a very large, deep-seated coastal landslide that is well known to geologists and engineers. It is about 3 km wide, and up to 350 m in length. There are nine Surveys in the National Landslide Database IDs 1774/1 to 1774/9.
The village of Capel-le-Ferne is situated behind the landslide at the cliff top, and the wide undercliff is given over to a country park.
The Dover to London mainline railway (via Cheriton) passes through the entire length of the Warren, with the Abbotscliff Tunnel at the eastern end and the Martello Tunnel at the western end. Since its construction the railway has been regularly disrupted by landslide activity, and considerable expenditure has been, and continues to be, involved in remediation and monitoring. The old Dover road is situated close to the cliff edge. This has also been disrupted, and re-routed in parts, for the same reason.
The geology of the platform at beach level varies along the length of the Warren. At the eastern end the platform changes from Gault Formation to Lower Chalk. The change occurs approximately in line with the eastern end of the concrete toe-weight apron (constructed in 1953), near Horsehead Point. Rock revetment has been placed to the east of the concrete apron by Network Rail. It is notable that westward of Horsehead Point the platform is displaced seaward by about 50m due to movements of the various slide masses.