Lyell Collection
Quarterly Journal of Engineering Geology and Hydrogeology
Lyell Centre  |   Lyell Collection  |   Subscriptions   |   Geological Society  |   Email alerts  |   Online bookshop  |   Help

Keywords:
Author:
Advanced search>>
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gallois, R.W.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation
Quarterly Journal of Engineering Geology and Hydrogeology; 2007; v. 40; issue.1; p. 29-34;
DOI: 10.1144/1470-9236/06-012
© 2007 Geological Society of London

Photographic feature

A recent landslide on the east Devon coast, UK

R.W. Gallois

Gallois Geological Consultancy, 92 Stoke Valley Rd, Exeter, Devon EX4 5ER, UK (e-mail: gallois@geologist.co.uk)

Received for publication 29 March 2006. Accepted for publication 21 July 2006.

The first 250 words of the full text of this article appear below. Images appear only in PDF or full-text views.


   Introduction
 
The largest landslides on the south coast of England are those associated with failure surfaces in montmorillonite- rich mudstones close to the base of the Gault Formation (mid Cretaceous). Those at Folkestone, Sussex (Trenter & Warren 1996), Ventnor, Isle of Wight (Hutchinson 2001) and Black Ven, west Dorset (Brunsden 2002) are among the largest active landslide systems in the UK. Westwards from Dorset, the Gault facies of the Albian Stage is replaced on the east Devon coast by sandstones and sandy calcarenites of the Upper Greensand Formation. These are mostly moderately strong rocks that crop out in almost continuous, precipitous cliffs between Sidmouth and the county boundary at Lyme Regis. They are a major component of the landslide debris, but the formation itself has not previously been shown to have initiated a failure. For example, the extensive Bindon landslide [SY 277 895] near Axmouth, which incorporates large masses of Upper Greensand, was attributed to failure surfaces in the Gault (Conybeare et al. 1840). However, that formation has not been recorded in a coastal section west of Lyme Regis.

Joint/bedding-bounded toppling failures have been observed from time to time in the highest, more massive part of the Upper Greensand along the east Devon coast. The most recent of these occurred after a prolonged period of wet weather in 2001 when a single block of about 3000 tonnes in the highest part of the Upper Greensand fell over 120 m from the western . . . [Full Text of this Article]