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| Dorset and East Devon Coast World Heritage Monitoring |
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| GCR Site: 800 Axmouth to Lyme Regis |
| Interest: Landslides |
| GCR Block: Mass Movement |
| SSSI: Axmouth to Lyme Regis |
| Site Boundaries: Grid Reference 325400, 89900 - 333700, 91700 |
| Date of Assessment: Trial |
| Date of last assessment: n/a |
| Surveyor(s): Richard Edmonds |
| Statement of Significance: |
| This is the most renowned area of landslipping in Great Britain. Although movements probably commenced towards the end of the Pleistocene, the very large Bindon Landslip of 1839, in the centre of the area, brought the site to public prominence. The features of the Bindon slip are now much obscured by vegetation, but the major topographic elements, for example the chasm-bounded block known as 'Goat Island', are clearly discernible from the air. The series of slides involves Chalk, Upper Greensand and Gault, and Triassic and Jurassic sediments beneath. Large-scale movements are infrequent, but smaller scale movements continue to the present day, notably near the western fringes of Lyme Regis. An historic site which has played an important part in the elucidation of landslip processes. |
| Physical description: |
| The Undercliff is a densely vegetated sequence of landslides that are remote from man made influences. The vegetated cliffs are a complex sequence of slipped blocks, broken ground and vertical cliffs. The beaches are remote. |
| Health and Safety: |
| The
only access through the undercliff is by the coast path. Or along the
beach. The path is often slippery, wet and rough going. A number of informal
paths run to various locations. Not surprisingly, away from the paths
the ground is difficult, broken and may contain hidden fissures. Some
areas, particularly near the seaward cliff sections, contain deep and
treacherous mudflows. Local knowledge is essential if survey work away
from the path is required. The beaches are rough and boulder strewn with obvious associated hazards. The cliffs are prone to rockfalls and landslides. At low tide the rocks are coated with slippery sawed. Spring tides will reach the base of the cliffs. The beach at Pinhay Bay (GR SY 318908) is cut by the rising tide. A potentially dangerous site. Mobile phone communications cannot be relied upon. Survey work should be undertaken in pairs. |
| Access: |
| As above. Beach access is from the Cobb at Lyme Regis or Axmouth Harbour |
| Conservation Objectives, on site: |
| Ensure
that natural coastal processes continue Maintain 'naturalness' of the site |
| Conservation Objectives, off site: |
| Record landslide events |
| Success indicators: |
| Natural processes continue and are recorded |
| Fixed Point photography: |
| The Lyme Bay and South Devon Coastal Group are considering establishing a long term coastal monitoring project similar to the Channel Coast Observatory and including the use of aerial photography. |
| Scientific publications and ongoing research: |
| Unknown |
| Natural Change: |
| Landslide activity continues above and onto Monmouth Beach. Activity recorded during Christmas 2002. |
| Large Landslide continues to move (2002/03) in the Pinhay Bay area from GR SY 320910 to SY 310904 (approximately) |
| Man made change: |
| Pinhay Pumping station has been abandoned. Disused pipes litter the slipped area below the site. |
| ENSIS unit summary: |
| Units 1 to 20 Favourable. A robust site |
| Comments: |
| Other comments: |
| 2005 will be the 50th anniversary of National Nature Reserve status for the Undercliff and a celebratory event is planned by English Nature |
| Sensitivity: |
| Low |
| Recommended survey period: |
| 3 years |
| Overall Assessment: |
| Favourable |
| Actions: |
| Record
major events: Promote removal of redundant pipes at Pinhay Pumping station Ensure that the interest of the site is incorporated into the next Shoreline Management Plan Work with the Lyme Bay and South Dorset Coastal Group (Engineers) to promote a coastal monitoring programme similar to the Channel Coast Observatory (Portland east to Selsey Bill) |
| Related GCR Blocks: |
| 87
Pinhay
Bay Fault Corner (West Bay) GCR Block: Hettangian - Pliensbachian GCR
1263 (Culverhole
Point) and 1264
(Pinhay
Bay) Rhaetian stratigraphy CGR
916 Lyme
Regis Jurassic Reptilia |
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Comments
and discussion
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