Palaeo-environmental Study Area P3 South-west coast, , UK

PALAEO-ENVIRONMENTAL STUDY AREA P3

SOUTH-WEST COAST, ISLE OF WIGHT, UK

AN AUDIT OF ARCHAEOLOGICAL AND PALAEO-ENVIRONMENTAL EVIDENCE FOR COASTAL CHANGE ON THE SOUTH-WEST COAST OF ISLE OF WIGHT, UK.

Plate P3 Seasonal cliff movements on the south-west coast of the Isle of Wight, UK are resulting in substantial losses. The common Agricultural Policy has resulted in increased arable land-use along the coastline. This has coincided with progressive erosion and the ‘Squeezing’ and loss of designated wild- life habitats at the edge of the receding cliffs

1. LOCATION

The south western coast of the Isle Wight comprises soft ferruginous sandstones and clays of the Lower Cretaceous. These soft lithologies make up a continuous cliff-line which is exposed to the maximum south-westerly winds and the fetch of the English Channel (Plate P3). This coastline is some 12 km in length being bounded to the west by the high chalk cliffs of Freshwater Bay and merging to the east with the landslide complex of the Isle of Wight Undercliff. The cliff-line of this coast is mostly some 40-50m in height but it occasionally

1 Palaeo-environmental Study Area P3 South-west coast, Isle of Wight, UK

descends to some 15m where old shallow valleys have been truncated by the advancing sea (Plate 3a).

A number of unusual geomorphological features distinguish this coast. At several locations the cliff-line is bisected by deep freshwater ravines which are locally known as (Plate 3b). The character of the chines is complex but there seems little doubt that their origins are associated with a rapid retreat of the cliff line during the later Holocene. This was followed by a consequent phase of renewed down-cutting by truncated local streams. Inland from the cliffs, the landscape is flat and rural with large arable fields often approaching the brink of the cliff. The exposed climate has often discouraged or ‘slanted’ the growth of hedges and there are very few trees. The maritime climate of this coast has encouraged some ecological anomalies. The cliff-line is designated a Special Area of Conservation being well endowed with a high diversity of habits and species including the notable population of Glanville Fritillaries (Melitaea cinxia), a European butterfly which is otherwise unknown in the British Isles. The Wealden clays, marls and sandstones exposed in the cliff faces are noted for their rich content of fossil dinosaur remains and footprints and for this reason the coastline at Atherfield designated for both its geological and geomorphological interest (Site of special Scientific interest; SSSI).

2. MODERN HUMAN GEOGRAPHY

The population of the south western coast of the Isle of Wight is rural and very low and there are no significant settlements. At the eastern end of the study areas lies Chale, a small medieval village which has lost part of its built landscape to coastal erosion at Chale Terrace. Another small undeveloped medieval settlement is Brook, a community where other coastal properties are threatened by the retreating cliff-line. These small coastal settlements are linked by an old military road which has since become an important route for coastal tourists (A3055). This coastline is designated an Area of Outstanding Natural Beauty and in summertime there is a high demand for access to the beaches at the foot of the cliffs.

3. THE CONTEMPORARY COASTAL PROBLEM

Cliff recession on the south west coast is a prominent phenomenon. The Isle of Wight Shoreline Management Plan (SMP) calculates the current rate of recession at up to 3m per year yet this figure tends to sublimate the nature of the phenomenon which includes individual embayed cliff-falls which may readily claim 20m or more in a single event. The Shoreline Management Plan recognises this coast to be undefendable and it accepts that a policy of ‘do nothing’ will incur the loss of Class 3 agricultural land as well as incursions into a highly valued tourist route, the Military Road, in the long term. For this reason the entire coast between Chale and has been classified as a single management unit (FRE1). Damage to the road is already an impending event at Brook Bay and Compton where rotational slips are fast approaching the road boundary and remedial measures are therfore being planned.

A further issue posed by erosion on this coast is the loss of cultural resources. The entire length of this coast is traversed by a coastal footpath which is similarly being squeezed. These paths regularly demand new negotiated diversions to avoid the relentless progression of the cliff-falls. These events are also responsible for losses to the cultural heritage as an extensive array of archaeological sites are revealed and promptly destroyed by fresh falls. While the present prescription for shoreline management accepts the inevitability of the sea’s advance there remains public concern over the loss of heritage on this coastline as well as the impact on the coastal Military Road, and therfore on the local economy.

4. KNOWN HISTORY AND PALAEO-ENVIRONMENTAL SETTING

The recession of the cliff-line on the south west coast of the Isle of Wight can be readily witnessed yet the history of this process is poorly understood. Cartographic evidence has been used to reconstruct cliff recession since 1794 and this seems to show some evidence of episodic losses. There is no other documentation of past changes to this other than references to two manors which are seemingly lost to the sea. At Brook a stream course accompanied by

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a small alluvial flood plain is truncated by the coastline. The present level of this flood plain lies some 4m above sea-level. The transect through these riverine deposits, exposed in the cliff face have revealed a deposit of peat and silt.

5. ARCHAEOLOGICAL AND PALAEO-ENVIRONMENTAL STUDIES AND POTENTIAL

The cliff-top deposits of brickearth offer potential palaeo-environmental evidence of the character of the early Holocene landscape prior to the sea’s advance. A Mesolithic horizon seemingly truncated by offers the opportunity to fix a date of genesis for chine formation and associated cliff recession. See Figure P3.1. Recent investigation of Roman habitation exposed in the cliff-face has produced midden evidence in which the presence of

certain marine Mollusca suggests a differing coastal environment in Roman times. Historical evidence shows a history of pastoral land-use on this coast and there is a suspicion that an acceleration in coastal erosion has followed a marked change towards the adoption of arable agriculture. 6. DESK-TOP ASSESSMENT SCORES

The sites on this coastline were not scored.

7. CURRENT APPROACH TO IDENTIFICATION AND PROTECTION OF THE ARCHAEOLOGICAL RESOURCE

The shoreline management plan abandons this coast to a policy of do nothing yet the loss of archaeological sites to coastal erosion is notably high. Moreover, some of these sites are perceived to offer information on the past character of the shoreline environment and these may also offer a guide to future coastal scenarios. The coastline requires an annual programme of professional archaeological monitoring backed by voluntary observations. It is uncertain whether the local authority can sustain such a provision.

8. CURRENT APPROACH TO IDENTIFICATION AND PROTECTION OF THE PALAEO- ENVIRONMENTAL RESOURCE

No protection can currently be offered for the palaeo-environmental resources on this coastline where the principal element of threat is natural erosion. The palaeontological problem exists where significant fossil remains of dinosaurs are quarried and removed from the cliffs by amateur and professional collectors and dealers. A case for a geological SSSI has been sought but with little success.

9. SUCCESSES AND PROBLEMS IDENTIFIED BY THE LIFE PROGRAMME

The execution of the 1998 coastal audit has provided a ‘blueprint’ or model for the means by which regular archaeological monitoring of the coastline should proceed. However, this audit was grant-aided by Central Government and there must remain some doubt as to whether the local authority has the resources or the resolve to sustain this action. See Figure P3.2a and P3.2b, an example of the information collected by the audit along the south-west coast of the Isle of Wight.

Historical evidence suggest that the rate of cliff-recession on the coastline has significantly increased and there is an observed possibility that there may be a causal link with the adoption of arable agriculture and the diminution of pastoral farming on this coastline. This change has been assisted by the Common Agricultural Policy and it raises the question as to whether subsidies should be more flexible and environmentally sensitive on vulnerable sections of the European coastline.

10. SOCIAL INCLUSION AND COMMUNITY INVOLVEMENT

The south west coast of the Isle of Wight is extremely popular with high school and higher education field study groups. Its geology is highly varied and the rapid rate of erosion regularly

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ensure that there are newly exposed cliff-faces to view. A voluntary group based on the Isle of Wight Museum of Geology regularly examines the cliffs and records and recovers palaeontological material. Potentially these activities could be extended to archaeological monitoring provided that the local authority could sustain the task of validation. The Isle of Wight Natural History and Archaeological Society monitors the natural ecology of the cliff top. The management issues concerning this coastline are well presented in the Isle of Wight Coastal Centre.

11. CONCLUSION AND KEY ISSUES

Shoreline management plans provide an objective means of prioritising coastal protection policies but their rigid adherence to a fourfold choice of options is not necessarily best suited to case in hand. In this case marked coastal erosion is of considerable concern to the local community yet it is occurring along a broad front that cannot be protected by ‘hard’ defences. The archaeological and historical evidence emerging on this coast suggests that the erosion may have been less drastic in earlier times and that a slowing mechanism may have been pastoral land-use. The opportunities to pursue such possibilities does not seem to be readily accommodated in the our-fold option.

Where farming subsidies are awarded on sensitive eroding coastlines a case can be argued for promoting land-use regimes which are specifically beneficial to the sustainable management of the coast. Archaeological, historical and palaeo-environmental research can be pertinent to the question of ascertaining the nature of past land-use and the scale and pace of past and present coastal changes.

4 Palaeo-environmental Study Area P3 South-west coast, Isle of Wight, UK

Plate P3a The soft eroding cliff-line of the south-west coast of the Isle of Wight, UK. Regular cliff falls on the coast are revealing and destroying archaeological and palaeo- environmental evidence of the former nature of this coastline, as well as continually providing a unique geological archive and also forming an important source of beach sediment. There is the need for increased recognition of the importance of on-going monitoring and recording in such situations along the European coastline.

Figure P3.1 Coastal erosion at Grange Chine, south-west coast , Isle of Wight Figure P3.2a The conditions, setting and age of sites identified in the rapid field audit of the south-west coast of the Isle of Wight FRE1 Figure P3.2b The conditions, setting and age of sites identified in the rapid field audit of the south-west coast of the Isle of Wight FRE2

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Plate P3b On the west coast of the Isle of Wight , UK, ravines known as ‘Chines’ mark the truncation of early Holocene river systems by a rapiderosive advance of the sea. The down-cutting of the Chines has been prompted by a shortening and steepening of the river gradient

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