Area: 627.4 hectares.
Within Area of Outstanding Natural Beauty. Partly within Heritage Coast Area. Partly owned by National Trust. Site has been extended and has part deletions. A Nature Conservation Review site for coastlands and lowland heathlands.
Description and Reasons for Notification:
The site is located on the north Cornwall coast and extends for some 20 km from Godrevy Head to Polberro Cove just west of St. Agnes. It lies mainly on Devonian sandstones and shales although the northern part of the site is composed of Grampound Grit. This coastline exhibits extensive maritime heathland and grassland in addition to sand dune and scattered scrub communities. These habitats contain a number of rare plants, and the cliffs, together with the offshore rocks, support large breeding seabird colonies.
The coastline between Godrevy Towans and Godrevy Head provides classic coastal sections for studies of the Quaternary stratigraphy and geomorphology of southwest England. At the base of the sequence a shore platform with a shattered rock surface is overlain by raised-beach, sandrock and head deposits. The sections demonstrate both lateral and vertical facies variations in the raised beach and head. The full succession of shore platform and overlying deposits, together with the sedimentary detail of the latter, provide a valuable stratigraphical record of changing environmental conditions, sea-levels and geomorphological processes during the late Quaternary, although firm dating control has yet to be established.
In addition Godrevy Point provides important exposures showing the complex sequence of fold structures produced during crustal compression at the time of the Variscan mountain building episode, at the end of the Carboniferous Period. Structures of four of the five main episodes of deformation of south Cornwall are present, affecting an altermation of slates, siltstones and sandstones of the Mylor Slate Formation. Variation in fold styles and attitudes reflects the variation of rock types throughout the section. At the northern end, small-scale tight, first-generation folds can be seen in slates with thin siltstone beds. Further south a complex pattern of interfacing structures occurs involving three phases of folds and related structures. The main fold here belongs to the third generation of structures and is deformed by fourth and fifth generation structures. Third and fifth generation structures had not until recently been differentiated and this site provides important evidence of the temporal relationships between them.
The wind pruned, ‘waved’ maritime heathland is dominated by ling Calluna vulgaris, with bell heather Erica cinerea, bristle bent Agrostis curtisii and western gorse Ulex gallii. Common throughout are saw-wort Serratula tinctoria, spring squill Scilla verna, burnet rose Rosa pimpinellifolia and betony Stachys officinalis, together with the rare pale dog-violet Viola lactea, the nationally rare Cornish eyebright Euphrasia vigursii and hairy greenweed Genista pilosa. In addition, the heathland along the Chapel Porth valley supports the nationally rare Dorset heath Erica cicliaris.
Red fescue Festuca rubra dominates the species-rich, fringing maritime grassland. Typical associates are wild thyme Thymus polytrichus, kidney vetch Anthyllis vulneraria and thrift Armeria maritima with the rarities golden samphire Inula crithmoides, tall ramping fumitory Fumaria bastardii, Cornish gentian Gentianella anglica subspecies cornubiensis and autumn squill Scilla autumnalis. This cliff grassland also supports a number of nationally rare species including shore dock Rumex rupestris, wild asparagus Asparagus officinalis and carrot-broomrape Orobanche maritima, which is parasitic on wild carrot Daucus carota.
The dune system at Godrevy exhibits extensive species-rich dune grassland developed on wind-blown calcareous sand. The sward is dominated by red fescue with abundant wild thyme, lady’s bedstraw Galium verum and eyebright Euphrasia officinalis. Pyramidal orchid Anacamptis pyramidalis and autumn lady’s tresses Spiranthes spiralis occur and the nationally rare slender bird’s-foot trefoil Lotus angustissimus has been recorded here. Dune scrub with wild privet Ligustrum vulgare and blackthorn Prunus spinosa is scattered throughout.
Another more restricted area of calcareous grassland occurs on wind-blown sand, on the slopes north of Porthtowan. Herbs are abundant in the red fescue and sea fern-grass Desmazeria marina turf, with oxeye daisy Leucanthemum vulgare, wild clary Salvia verbanaca and the rare Portland spurge Euphorbia portlandica. Of particular note is the presence of a large colony of the nationally rare spotted cat’s-ear Hypochoeris maculata.
The exposed rocky intertidal shore supports a varied flora and fauna including the scarlet and gold star coral Balonophyllia regia, a species rarely recorded on Cornish coasts. Grey seal Halichoerus grypus breed in inaccessible sea caves.
The Godrevy Head to St Agnes coastal section supports a rich invertebrate fauna. Twenty-five species of butterfly occur here including green hairstreak Callophrys rubi, small pearl-bordered fritillary Boloria selene and the nationally scarce silver-studded blue Plebejus argus. Ten species of dragonfly and damselfly Odonata have been recorded, including emerald damselfly Lestes sponsa and the nationally scarce blue-tailed damselfly Ischnura pumilio.
The cliffs and offshore rocks provide important nest sites for a number of breeding seabird species including guillemot Uria aalge, razorbill Alca torda, cormorant Phalacrocorax carbo and the largest breeding colony of kittiwake Rissa tridactyla in Cornwall. Peregrine Falco peregrinus and rock pipit Anthus spinoletta breed on the cliffs whilst stonechat Saxicola torquata nest in scattered cliff-top scrub.