The Sea Coast

So much for legend; excavation and analysis have produced the facts. The Oratory was built at the head of a little fertile combe in the sixth or seventh century. It is not quite certain if St. Piran actually built it. It was an Oratory and not a parish church. Gradually accumulating sand caused the adjacent spring to change its course so as to threaten the western wall of the Oratory; consequently, a stone dam was built, probably during the eleventh century. The relics of St. Piran were enshrined here, and the Oratory became a mediaeval pilgrims’ shrine. For this reason another doorway was made, and a new one substituted for the original Celtic doorway. This alteration was probably finished in the twelfth century. Up to the time of the Reformation the Oratory was kept clear of sand so that the relics of the saint could be seen. But when the destruction of shrines and images took place, the Oratory roof was removed. This was early in the reign of Queen Elizabeth. The Oratory was thus neglected and was gradually surrounded by sand. Yet Camden, in 1586, speaks of it as “on the sands,” and Wilson

(#ulink_24d8cef5-8461-5169-856e-a45d7ea234d4) says it could still be seen in 1608. Soon after this the sands covered it, and it was lost, until in 1789 the shifting sands again exposed the western gable. In 1835 it was excavated by William Michell, and by William Haslam in 1843. Then it was neglected until 1892, and finally excavated and partly restored in 1910.

The Old Parish Church was built between the ninth and eleventh centuries, about one-third of a mile east of the Oratory, in order to avoid the encroaching sand. Part of this building still survives, and it is to it that the Domesday survey refers. Additions were made to this Church in the twelfth and fourteenth centuries. Up to the beginning of the seventeenth century, it was free from sand, but then mining operations diverted the stream which flowed between it and the Oratory—this stream had been a means of checking the sand advance—so that the original stream bed dried up and sand began to threaten the church. For the next two centuries various attempts were made from time to time to restrain the sand, but eventually it prevailed. Parts of this church were removed, but most of it was left, and it was still visible in 1848. The present church was consecrated in 1805.

Other coastal areas of north Cornwall were also ruined by sand. The Gwithian sands cover about the same area as do those at Perranzabuloe, and seem to have formed in the Middle Ages. In the seventeenth century they were a menace, and Lelant Church was invaded. East of the Hayle river these sands caused the deterioration of a considerable area of good agricultural land. Somewhat similar, but less extensive damage was done by sand advancing on to farm land south of Trevose Head. St. Constantine’s Chapel was also destroyed. North of the Camel estuary is an extensive dune area at St. Minver. These dunes were threatening St. Enodoc’s Church in the first decade of the nineteenth century, and finally ruined it.

In all these cases there is an obvious parallel with South Wales. The present dune areas were, as far as the very slender evidence goes, quite free from sand in the sixth and seventh centuries.

FIG. 8 Coastal changes at Southport. (From information supplied by Borough Surveyor)

By the thirteenth and fourteenth centuries dunes became a serious menace. There was apparently a more stable period in the sixteenth century, and a renewed advance later.

Southport illustrates admirably the growth of a modern town on recent accumulations of blown sand. A map dated 1736 shows the site of Lord Street, the chief thoroughfare of the town, as “The New Marsh,” and washed by high tides. By 1834 a new range of dunes had formed to seaward, and “Lord Street” was then a line of slacks or fresh-water pools. Extensive reclamations were later carried out, including the extension to the North promenade, and the building of the Marine Lake and Marine Drive in 1887–1895. The last sea-bank around the Municipal Golf Links was made in 1931–32. In the Crossens district (the north-west end of Southport) considerable changes have taken place, and are shown in Figure 8. In recent times reclamation in this part has been carried out by the planting of a stretch of fore-shore below high-water mark with grass sods, or samphire, set out at about one yard intervals. These gradually grow together to form a close turf, and the level also rises with the deposition of tidal silt. When conditions are judged fit, an embankment is built to exclude the sea, and the reclaimed area is drained. In the southern part of the town and nearer Birkdale the coast has altered far less. There has been some outward growth since the coast at one time followed what is now Rotten Row.

What has been said so far shows that even during the last two or three centuries it is far from easy to make any exact assessment of coastal changes. They are known quite well qualitatively, but not quantitatively. It is only occasionally that we find reliable data which allow us to fix details with certainty. In still earlier times the record is worse, and before the period of maps and plans we have to rely on descriptions and perhaps tradition. Sometimes we can check this evidence by careful archaeological or geological excavations, but even so we seldom if ever get precise measurements except at the place of excavation, and even there the evidence is sometimes equivocal.

In Wales, Cornwall, Ireland, and Brittany there are many legends which have as their theme the overflowing of wells or lakes or the drowning of low-lying areas by the sea. In the Isles of Scilly and the neighbouring parts of Cornwall there is the legend of Lyonesse—the fertile land that formerly was supposed to extend beyond Cornwall. This land was alleged to have been overwhelmed by the sea, leaving but one survivor, a man named Trevilian, who was able to mount a swift horse and escape to the mainland. Geological and perhaps archaeological evidence certainly supports the view that land has been comparatively recently submerged in the Isles of Scilly, and although this submergence may have included the rocks called the Seven Stones, mid-way between the islands and Cornwall, there is no ground whatever for the tradition that these rocks mark the site of a large city.

Off Penmaenmawr in North Wales there is visible at low water a patch of seaweed-covered stones called Llys Helig. These have been described as the ruins of a palace which was inundated between the fourth and ninth centuries. It has been conclusively shown

(#ulink_935f98ab-a048-59cd-888d-f080f23669a3) that this story is only about a hundred years old, but it is nevertheless often regarded as history based on the authority of “An Ancient Survey of Pen Maen Mawr” by Sir John Gwynn, who, in turn, refers to earlier “authorities.” According to the Survey, Helig and his people, when the supposed sudden inundation took place, fled to Trwyn ‘r Wylfa, a hill in the parish of Dwygyfylchi, which is still sometimes referred to as the Hill of Mourning. But recent examination of the legend and also of the site of Llys Helig, has shown that the legend is a fairly modern tale, and that the palace is nothing else than a heap of large stones—the remains of a former glacial deposit, similar to the scars so frequently found on the Cumberland coast.

The most interesting example illustrating the inter-relation of physiography, geology, archaeology, and folk lore is to be found in the legend of Cantref y Gwaelod. In Cardigan Bay there are several Sarns, or causeways, running seawards from the coast. The longest is Sarn Badrig, or St. Patrick’s Causeway, which runs south-west from Mochras Island for about twenty miles, nine of which may be exposed at a very low ebb. The others are shorter: Sarn y Bwch is about a mile long, Sarn Cynfelin seven or eight miles, Sarn Dewi about a quarter of a mile, and Sarn Cadwgan one and a quarter miles long. They are all formed of loose rounded stones and boulders and are quite narrow. Tradition has it that some of them represent the remains of masonry. This, however, is false; they are entirely natural features.

The first mention of the lost land, or lost hundred, of Cantref y Gwaelod occurs in the so-called Black Book of Carmarthen, which belongs to the twelfth century. There the cause of the flooding is ascribed to one Margaret or Meredig “who, at times of feasting, allowed the water of a magic well, under her charge, to overflow the country.” The more popular tradition blames a certain Seithennin, who, in his cups, neglected the sluices. In course of time the legends varied, but Seithennin remains the central figure. In 1662 this story was connected with Sarn Badrig by Robert Hengwrt. Later writers embellished this suggestion, and in the eighteenth and nineteenth centuries there was a collection of tales and legends to the effect that Cantref y Gwaelod had been drowned in historic times as a result of carelessness. Hence, it is not surprising to find that an actual date is ascribed to the event, namely A.D. 520. There is no historic support for this. The Romans did not occupy any of the coastal area between 55 B.C. and A.D. 409, and no mention is made either of the lost land or of the catastrophe in Antonine’s Itinerary, or by Ptolemy, or by Giraldus Cambrensis.

Is there, then, any foundation for the inundation legend? Certain facts are important. The sarns are natural features; at Borth and other places there are submerged forests indicating changes of level; this and the existing distribution of boulder clay on and near the coast clearly imply that much of Cardigan Bay was a low lying boulder clay plain before a geologically recent subsidence or submergence took place.

Somehow or other it seems that a tale of a former land in Cardigan Bay has come down to us from remote antiquity, and it is one of many similar tales. “The numerous interesting features which these tales have in common seem to suggest the existence in past times of people who were supposed to live in lakes, were small of stature, disliked iron, possessed few articles of furniture, had not learnt the art of making bread, disliked the greensward being broken up by the plough, were successful in tending animals, had a limited ability to count, and probably used a language of their own which no-one else understood. They appear also to have reckoned descent in the female line. If this suggestion is accepted, these characteristics are consistent with a pastoral people in a primitive state of culture, who were not acquainted with the use of iron, but who attributed great importance to stocks of cattle, sheep and goats, and knew little or nothing about tilling the ground and the growing of corn.”

(#ulink_8de6ca12-bad3-562f-8759-b1269e00dabe)

This description might well apply to the Bronze Age people, whose pile-dwellings make clear their intimate association with lakes. The later Iron Age peoples, with better weapons, must have frightened the earlier inhabitants. An anthropological investigation of Central Wales has revealed that a short, dark, and rather long-headed people are associated with remote hill lands, in fact in places where traces of Neolithic man are still common. In the Mawddach valley, around Towyn and in other places is another type. In these places Bronze Age pottery is found. The distribution of these people suggests they came later than the dark hill folk. Later still came the iron using people.

It is, therefore, possible that the folk tales, a better description than legends, go back at least as far as the early contacts of the Iron Age people with the peoples already living in Wales, or it may even be that the tales date from the remoter past when the Bronze Age and Neolithic peoples were first in contact.

There is little doubt (see Chapters 8 (#litres_trial_promo) and 9 (#litres_trial_promo)) that in or before the Neolithic period the boulder clay reached some distance out into Cardigan Bay as a low-lying plain through which the rivers pursued winding, sluggish courses. The post-glacial rise of sea level included the Neolithic period, but probably ceased fairly soon after it. It is likely that the submergence was wholly or nearly complete in the Bronze Age. It has been argued with conviction that many of the present inhabitants of Wales are the direct descendants of Neolithic man, and it is at least possible that their remote ancestors actually witnessed the drowning of the coastal plain. In short, we may have in the legend of Cantref y Gwaelod the gist of a folk tale that has been handed down from a very remote period of human history.

One final word: the sarns are formed of boulders that were contained in the boulder clay; there is no reason whatever for ascribing their formation to any human element. It is, however, difficult to account for their long and narrow shape. Sarn Badrig and Sarn Cynfelin occur about mid-way between river mouths, thus suggesting the idea that they are in some way continuations of the watersheds between adjacent streams.

(#ulink_5e1aeec6-9c07-5c27-a3c6-9d1df2f2c160) For recent information on Holderness I have made considerable use of an unpublished report, 7 July 1947, by G. M. Hines and C. Pinsent, Research officers to the Ministry of Town and Country Planning (Leeds), and shown to me by the kindness of the Regional Controller.

(#ulink_a18c26f0-e921-5375-b460-1091f0178670) The Lost Towns of the Yorkshire Coast,” 1912, p. 42.

(#ulink_b763ac49-051c-5b9f-9fd2-245233c08ca3) It was later removed.

(#ulink_b763ac49-051c-5b9f-9fd2-245233c08ca3) Letter 10.9.1948 from the County Planning Officer (Norfolk) to the Regional Controller, Ministry Town and Country Planning, Cambridge.

(#ulink_8ab06476-ba84-567f-9ced-62d03fb6af95) The figures are kindly given to me by the Cambridge office of the Ministry of Town and Country Planning.

(#ulink_486fa500-f116-56fd-830a-b7f915c2b2f4) Partly from a plan prepared by F. W. S. Stanton about 1908, and further details from information supplied to the Ministry of Town and Country Planning (Tunbridge Wells), and passed to me by Mr. H. R. Wardill.

(#ulink_c929b925-874a-571d-832f-85360a042745) Based on information given to me by the Department of Health for Scotland.

(#ulink_f35b2590-db56-5433-b087-89097395f011) Halophytes are plants which will live in soils containing an appreciable amount of common salt or of other organic salts.

(#ulink_f35b2590-db56-5433-b087-89097395f011) C. P. Petch, Reclaimed Lands of West Norfolk, Trans. Norf. Norw. Nat. Soc. 16, 1945, 106.

(#ulink_5b485e8a-35cc-54d9-8cb9-43abb053fea9) A. G. Tansley, The British Islands and their Vegetation, 1939, p. 828.

(#ulink_06938981-4614-5f67-94b0-e1caca04e3a3) Royal Commission on Coast Erosion and Afforestation: Final Rept. p. 135, para. 49.

(#ulink_6759b3eb-4f04-57dd-b58f-fe771a900c7f) V. B. Redstone, Memorials of Old Suffolk, Ch. XII. (The italics are mine, J.A.S.).

(#ulink_b979d024-ff69-5b55-b656-f138e6e6f680) An account of the historical fluctuations of the bar of the river Findhorn, on the Moray Firth, is given on page 143. All river harbours deflected by a sand or shingle bar have similar stories, but the examples given are sufficient to illustrate the general subject.

(#ulink_2ef35c13-276f-59d5-b609-d021264e9708) Arch. Cambrensis, June, 1933.

(#ulink_2ef35c13-276f-59d5-b609-d021264e9708) L. S. Higgins, op. cit.

(#ulink_ab6d5a38-09e5-58ff-b06b-b61b0384039c) A Cornish Legend: the Three Churches of Perranzabuloe. Truro, City Printing Works, 1923. Dr. N. J. G. Pounds put me in touch with various sources dealing with coastal sand areas in Cornwall.

(#ulink_089d2cc1-4c94-5b17-94a1-262399e7ed4e) The English Martyrologe, 1608, p. 116.

(#ulink_a7d6a517-8fac-5d60-b434-d2789004ac8b) F. J. North, Supplement to the Llandudno, Colwyn Bay and District Field Club Proceedings, Llandudno, 1940.

(#ulink_837a3210-07b3-5194-9224-a95d42f9f935) O. T. Jones, The Welsh Outlook, January, 1941.

CHAPTER 4 (#ulink_3c1d2d51-4b9c-5b8e-bc5e-9ba942343180)

THE COAST IN PROFILE AND PLAN

BEFORE discussing particular stretches of coastline formed by rocks of various types, a general review of the nature of cliffs and of the shore profile is desirable.

Let us assume that the sea comes to rest against the land at a certain level, and that that level remains unchanged for a long period of time. What will happen depends on a variety of factors, and to make the matter clear it will be convenient to discuss certain special conditions.

If the land is formed of soft rocks and is low and flat, the waves will begin to cut a slight notch in it. The notch implies a cliff and a platform, which develop concurrently. If the initial slopes of the land are gentle, the cliffs are not likely to attain any great height, but the platform can widen considerably. But in order that it may widen, it must also slope seawards. In the early stages the cliff and platform are insignificant, and only those waves reach the cliff foot which can traverse the shallow water off shore. With the increasing width of the platform, the waves crossing it lose much of their power. At the same time the larger storm waves will break near the outer edge of the platform and gradually wear it down, thus enabling other waves to traverse it. A factor of great importance in this connection is the tidal range. At high tide the platform may be covered by several feet of water and the waves can run over it and erode the cliff. At low tide the platform may be wholly or partly exposed. This statement immediately poses a difficult question. At what level are platforms cut? There is no definite answer to this, and the difficulty is not lessened if we consider cliffs and platforms around our own coasts, because it is not always clear that they are entirely the product of present-day conditions—in fact we may be reasonably certain that they often have a long and complicated history associated with former shifts of sea level.

Some writers argue that platforms are cut mainly at and near high water. In order to think about this matter it is advisable to disregard any existing platforms and consider what might happen in an ideal case. Suppose in Figure 9 AB represents average high-water level, and CD average low-water level. (This in itself is an improper simplification, since in a tidal cycle all levels between these two selected ones, as well as some above or below them, are reached). It is clear that the waves can erode effectively at all levels between the two lines. In early stages we may probably assume somewhat irregular erosion, but since it is only at and near the time of high water that the higher levels can be attacked, it is plain that erosion near the AB level is associated with high water. But at low water all or nearly all above the CD level is exposed and cannot then be eroded by the waves. With the rise of the tide, waves, at first small, but gradually increasing with the increasing depth of water, can traverse the slope DB and it seems likely that the most effective erosion of this slope must take place, other things being equal, at and about high water.

FIG. 9 Cutting of Platforms

The bigger waves can attack it in its outer parts and gradually wear it down, and smaller but still effective waves can traverse it and attack the cliff in the rear. In ordinary conditions the waves need not be large and can travel over it easily: the differentiation in the size of the waves really only applies to the contrast between storm and normal conditions—but it is under storm conditions that the real work of erosion is so often accomplished.

It may, however, be argued that platforms are more easily cut below average low water level. It is true that below this somewhat arbitrary level the sea floor is nearly always covered with water and therefore in a position to suffer erosion. Moreover, at high water, the bigger waves can travel over it and add their quota to the erosion that takes place at (and near) low water. This may be true, but simple low water erosion presumably implies that the cliff foot should begin at that level and, except in so far as beach deposits may obscure it, at high water the cliff foot should be well submerged.

Since we are uncertain about the levels at which platforms are cut, we must either ignore, or at least refer with care, to those around our own coasts, so that we do not beg the question. However, it is likely that in soft rocks existing platforms are largely, perhaps wholly, the result of present conditions, e.g. the Garstone platform off Hunstanton and the Chalk platform around parts of Kent and Sussex. If that assumption is correct, it is almost certain that the effective cutting takes place only above mean sea level and especially near the time of high water. Low water cutting of many existing platforms at springs is impossible, and even at neaps is negligible.