The Valley of Rocks, Lynton

An alternative geological history of this popular tourist spot.

Finding the Valley of Rocks

Take a map of the Bristol Channel, that stretch of water that separates the West of England from South Wales. Look along the North Devon coast and find the twin villages of Lynton and Lynmouth.

Lynmouth, at sea level, is situated where the East and West Lyn rivers enter the Bristol Channel. Lynton is some six hundred feet above, where it is perched on a ledge above Lynmouth in a valley of its own. Follow this valley to the west and you will find yourself in the Valley of Rocks.

The Topography

To start this journey through space and time, climb to the top of Hollerday Hill, which is placed between Lynton, the Bristol Channel and the Valley of Rocks. Stand on the summit of Hollerday Hill and look around you.

To the North the Bristol Channel stretches out before you. Beyond that the southern coast of Wales can be seen in the distance.

To the East you can see along the Channel towards Bristol. Foreland Point juts out into the Bristol Channel just along the coast and little of the Exmoor coast beyond it is visible, being hidden by this headland. The western coast of Foreland Point curves around towards Lynmouth and it forms part of Lynmouth Bay.

At the inland end of Foreland Point is the village of Countisbury. The road from Countisbury is clearly visible as it winds steeply down a ridge, dropping one thousand feet as it descends into Lynmouth. This ridge separates the Bristol Channel from the East Lyn valley on the other side. Unusually, the East Lyn runs parallel to the coast, but only a very short distance from it, until it reaches the sea at Lynmouth.

On the south side of the East Lyn valley is Summerhouse Hill. This hill separates the East and West Lyn rivers. The West Lyn flows northwards and joins the East Lyn at Lynmouth just a little way inland from where the East Lyn joins the Bristol Channel.

Continuing westward, Station Hill can be seen across Lynton. Further west this becomes Southcliffe and forms the southern side of the Valley of Rocks.

Look carefully and you will see that the valley that contains Lynton once was a lake where the West Lyn River joined the East Lyn River.

The Valley of Rocks is bounded on the north by Hollerday Hill, which extends to a rocky ridge known as Rugged Jack and a little beyond that by Castle Rock. This line separates the Valley of Rocks from the Bristol Channel although there are breaks on either side of Castle Rock.

The Valley of Rocks can be seen, some three hundred feet below the summit of Hollerday Hill. It is the continuation of the valley that encloses Lynton on the north and south.

Following the line of the valley westward from Lynton it curves round Hollerday Hill turning toward the Bristol Channel. It approaches the Channel but it is deflected by Rugged Jack and so runs parallel to the coast, with only Rugged Jack separating the valley from the Bristol Channel.

The current line of the valley ends just beyond Castle Rock where the ground drops away to become Wringcliff Bay. From the top of Hollerday Hill it can be seen, however, that the floor of the valley rises again beyond Wringcliff Bay and the valley continues through the grounds of Lee Abbey sinking again and then eventually drops to sea level where it joins the Bristol Channel at Lee Bay.

Strange as it may seem this is a drop of some 600 feet from the centre of Lynton to the sea at Lee Bay.

A Glacial Valley

If, from the top of Hollerday Hill, you look at the floor of the valley, as it curves round Hollerday Hill from Lynton, through the cemetery and then reverses direction and goes towards Lee Abbey, one thing soon becomes obvious. The bottom is bowl shaped and the logical conclusion is that it has been carved out of the rock by the action of a glacier. The Valley of Rocks is a glacial valley.

If you look across the valley and up the opposite side, you can see that Southcliffe, which forms the southern side of the valley, is higher than the summit on which you are standing. In contrast, the ridge separating the Valley of Rocks from the Bristol Channel - Rugged Jack - is considerably lower than both Hollerday Hill and Southcliffe. This raises an interesting problem. In order for a glacier to create this valley in the way that it has, this wall formed by Rugged Jack and indeed Hollerday Hill, needs to have been much higher. What is more, this wall is broken in at least two places, well before any glacier in the valley would have reached the sea. In its present form it would have been an ineffectual barrier to a glacier - and yet there most certainly does seem to have been a glacier here at some time. At some time in the past the northern wall of the valley must have been much more substantial.

A Small Glacier

I must now ask you to use your imagination. The various situations that I am about to describe require you to fill in some very real gaps in what you can see. It is only by filling in those gaps that you will be able to understand what follows.

Let us take a trip back in time to a time of an ice age - to a time when substantial areas of land were covered with ice. The last ice age is generally believed to have ended some ten to twelve thousand years ago. For our purposes that is far too recent. For reasons that I hope will become clear, the situation that we are about to observe could not have happened in the last ice age.

As we shall see later, the last ice age was quite possibly the most severe of a series of ice ages. The situation that I am about to describe requires a lesser ice age. It may or may not have been the penultimate one. At this stage I shall assume that it is. It is not important. On the other hand further research may throw up reasons why we have to go back further in time.

As ice ages go, this one is not severe. We are able to stand on the top of Hollerday Hill and look down into the Valley of Rocks. The hill on which we are standing and the hills surrounding us are quite probably still covered with a thick layer of snow, although this could be melting. Beneath us in the valley there is a glacier. Compared with earlier glaciers this is quite small. It may only be the remains of a much bigger glacier or it may never have been any bigger. It does not extend in height above Rugged Jack and it only reaches as far as Wringcliff Bay before turning towards the Bristol Channel.

The valley continues along a path dropping downward into the Bristol Channel. This path will be destroyed some time in the future. Although the grounds of Lee Abbey are covered in snow, the glacier does not extend that far or if it does the flow is not of any great significance.

Lynmouth does not exist. What will eventually be known as Lynmouth is at present buried under several hundred feet of rock. This is a substantial rock wall which extends between Countisbury Hill and Hollerday Hill and is as yet unbroken. The bed of the East Lyn is some six hundred feet higher than at present. There is no river running through it. It is the upper part of the same glacial valley that a little further on becomes the Valley of Rocks and the glacier running along this valley is the same one that we have just been looking at a little further along its path.

Come back to the present time and stand on one of the hills overlooking Lynton and study the topography. The ground at the western end of Lynton is higher than that at the eastern end. This is odd as the flow of the glacier through this valley is from east to west. Look towards the eastern end of Lynton. You will see that beyond St Mary's Church and what was the Royal Castle Hotel, the land drops away very steeply. In places it is almost vertical. Now travel back again to the time of our glacier. The area, which in the present day is occupied by Lynton, is the western end of an ice lake. The eastern end extends a little way up the valley of the East Lyn. To the south, this lake probably also extends a short distance up the valley of the West Lyn. It is possible that a similar glacier is flowing down the valley of the West Lyn to join up with that of the East Lyn at this lake. They will then combine and flow out to the west and along the Valley of Rocks. Even this combined glacier is not big enough to extend above the height of Rugged Jack.

As this is a very small glacier as glaciers go, we can draw the obvious conclusion, that this is a lesser ice age. There may have been other ice ages before or after this one which were even less severe. The ice may never even have extended this far south. As far as we are concerned, these can be ignored. We are only interested in those that covered southern England with ice.

At least one earlier ice age has been more severe and, similarly, at least one later ice age has been more severe. They are certainly necessary for this theory. As we shall see, it is unlikely to be the most recent ice age.

Although later there may well be a considerably thicker layer of ice, changes in the topography will ensure that this is the last glacier to flow along this particular path. At the end of the subsequent - and possibly most recent - ice age, the valley wall will be broken dramatically at Lynmouth, leaving a much easier path to the Bristol Channel and as a consequence Lynton and the Valley of Rocks will be stranded almost literally high and dry.

A Larger Glacier

Let us travel further back in time to an earlier ice age or to an earlier time in the same ice age. The glacier in the Valley of Rocks is much bigger than the later one we have just looked at. Maybe we can still stand on the top of Hollerday Hill but the snow is fairly thick and the glacier almost reaches to where we are standing.

There is a significant difference in the topography. The bottom of the valley is higher - possibly 100 ft(30 m) - although we can not see it because of the glacier. The wall on the northern side of the valley is probably as high as Southcliffe on the other side, if not higher. It has to be this high or the glacier would just run over the top.

This glacier extends beyond Wringcliff Bay through the grounds of Lee Abbey and then turning north and running through Lee Bay. Because of the lower temperature and a difference in sea level, this glacier is probably extending considerably further out into what is now the Bristol Channel, possibly for several miles more.

The wall on the north side of the valley is much higher. It must also be much more substantial. This wall has to be capable of withstanding the great force being exerted on it by the glacier, without giving way. The only way that is possible is if there is a significant land mass beyond this wall and supporting it.

The only conclusion that can be drawn from this is that the Bristol Channel as we know it just does not exist yet. The moorland extends north across the area of the Bristol Channel, possibly even joining up with the similar landscape of South Wales.

This moorland is covered with a thick layer of snow as far as you can see. Whichever direction you look there is snow. Somewhere out there in the Bristol Channel, the River Severn will be carving its path through to the sea. Like the Lyn rivers it too will be a glacier. On the other side of the Channel the Nydd (Neath) and the other rivers of South Wales will be doing the same thing.

This vast volume of ice has to come from somewhere. The only possible source is the great oceans of the World. As there is now a considerable amount of ice sitting on the land the sea levels will be much lower. The land mass may well now extend as far as the edge of the continental shelf. As a consequence the glaciers have further to travel until they reach the sea.

The land may be covered in snow and ice. It may be totally inhospitable. On the other hand, there may be some life surviving here, just as life can survive in the arctic regions today. One thing that we can be certain of is that although this ice age is far more severe than the later one that we have just witnessed, this is still only a relatively minor ice age. Between this ice age and the present there will be times of such devastation that the land that fills the Bristol Channel in this scenario will be swept away completely.

A Possible Chronology

If we look again at this area we find evidence of at least three geological stages.

1. The Valley of Rocks is a glacial valley with walls high enough and strong enough to force the glacier as far as Lee Bay and beyond. This may or not be a severe ice age, but either way there is worse to come.

2. The Valley of Rocks is still a glacial valley. Whatever was supporting the northern wall of the valley at Wringcliff Bay has gone allowing the glacier to fall into the Bristol Channel at this point. The once substantial land mass supporting Rugged Jack has all but disappeared - and yet the glacier is still flowing from the valleys of the East and West Lyn through Lynton and on to the Valley of Rocks. Quite clearly, just a little way to the east, there is still a substantial wall forcing the glacier to continue along that route. The breakthrough at Lynmouth has yet to happen.

3. The Valley of Rocks is now dry, as the East and West Lyn rivers are now reaching the sea at Lynmouth. This is the situation as we know it today.

Who knows what happened before stage 1? That is another story waiting to be written.

Gentle Ice Ages

So what happened to cause the change from stage 1 to stage 2 and from stage 2 to stage 3? There is no definitive answer. Current uniformitarian theories merely put forward the argument that there was gradual change over many millions of years. They argue that the ice gradually expanded and crept slowly over the land from the poles and then very slowly receded again.

Generally they do not even allow for the ice to have crept this far south.

The uniformitarian theories, of course, contain no possible explanation of why the ice ages start and then finish. It is just accepted that this is the case. They gradually creep, spreading out as the ice flows from the poles to form the ice age and then recedes back to the poles as the ice age ends. No other explanation is forthcoming. It does not require an expert to see that neither the geological record nor the mechanics of ice flow, support this theory.

For many years the uniformitarian theories held sway. Earth had slowly formed out of hot gases, cooled down and eventually ended up the way it is now. Catastrophes were just not allowed. The thought that the solar system was behaving more like a giant snooker table (rather like those images in 'The Third Rock From The Sun') just could not be entertained. A few years ago the possibility that there had in fact been a catastrophe was allowed to creep in. The possibility that an asteroid or comet had struck Earth some 60 million years ago became just about acceptable. It was this incident that wiped out the dinosaurs. Everyone knew that the dinosaurs had disappeared rather quickly, so this theory was allowed to stay. It rather mucked up uniformitarian theory, but that's life. But to be on the safe side only one of these strikes was allowed.

Unfortunately, very recently, on two separate occasions, asteroids have been discovered coming uncomfortably close to Earth. One of these was only discovered when it was on its way out. This leads to the possibility that there may have been one or two more of these things whizzing around in the past. If there is a significant number of them, then the chances of one of them actually making contact are quite high. One every few hundred years may be quite possible and may well have happened.

Consider the possibility of one or more asteroids hitting the ancient moorland that once filled the Bristol Channel. They would cause a tremendous upheaval in this area. Considering the speed at which they would be travelling, even a small one would be quite devastating. At the point of impact there would be very large explosion basins or craters left behind. Considerable amounts of rock at the point of impact would be vaporised and thrown up into the atmosphere. Further away, the rocks would be pulverised and the resulting dust would also be thrown up into the atmosphere. Further away still the rocks around the edge of the crater would be raised up and folded.

There is a possibility that asteroid strikes such as this one actually caused the ice ages, although they would have had to been much larger. That is also another story yet to be written.

This asteroid strike may well have caused such devastation that it weakened the rocks on the seaward side of the Valley of Rocks. In the nature of Newtonian physics the glacier would prefer to continue in a straight line rather than be forced around a curve. As our earlier glacier pushed up against Rugged Jack and Castle Rock, the sides of the valley on to the east and west of Castle Rock gave way. Whatever had been supporting them on the seaward side was either no longer there or was very weak and was itself unsupported. It was now either floating around in the atmosphere or was collapsing gradually.

The later glacier, which could well have been the remnants of the earlier glacier, found an easier route as it started to head north at Wringcliff Bay. At first it may have been big enough to follow both routes and so still went through the grounds of Lee Abbey. In the early stages the line would have extended northwards from Wringcliff Bay, but as the land gradually disappeared and the glacier reduced in size, it abandoned the Lee Abbey route as the Wringcliff Bay route became easier to follow. At the end of this ice age the Valley of Rocks may well have ended up somewhat as we know it today, and by then this same glacier could have started to make the break though at Lynmouth

A Much More Devastating Change

The change which allowed the rivers to run to the Bristol Channel at Lynmouth and which left Lynton perched on its rocky ledge happened later and probably as the last ice age came to an end. Once the breakthrough happened at Lynmouth the route through the Valley of Rocks became redundant.

If you look at the topography of Lynmouth and the surrounding hills, you are inevitably drawn to the conclusion that at some time the West Lyn has dramatically carved its way across the East Lyn, diverting that river and leaving Lynton stranded high and dry.

This can be seen by standing in Lynmouth and looking up towards Lynton. It can also be seen from Summerhouse Hill, from where there is an excellent view over both Lynton and Lynmouth. Lynton seems to be perching on a ledge.

In Lynton, this can be seen quite clearly from St Mary's churchyard or from North Walk where it crosses the Cliff Railway.

The general shape of the East and West Lyn valleys are significantly different. Looking along the East Lyn the glacial valley is still obvious but the bottom has been carved away so that lower down it has become 'V' shaped. While the slope could never be called gentle, the river valley rises regularly meeting Hoar Oak Water at Watersmeet. At Brendon, some three miles from Lynmouth, the river is roughly the same height as Lynton. From Watersmeet, Hoar Oak Water is much steeper and reaches the height of Lynton at Hillsford Bridge, only two miles from Lynmouth.

The West Lyn in contrast, is very much steeper. At Lynbridge, only half a mile from Lynmouth it is very nearly at the same height as Lynton, which it reaches at Barbrook, only another half mile away. This valley has obviously been carved out with much more violence than the East Lyn.

The ice ages we have been considering have been relatively gentle. They created glaciers that flowed through the Valley of Rocks. These glaciers in themselves did not cause great damage. They merely cleared away the rubble from the asteroid strikes.

In contrast the last ice age was quite devastating.

We now have to imagine a dramatic and sudden climatic change causing the ice to start melting. We know from our own experience that when a thaw sets in it usually happens very quickly. There is no reason to believe that this does not apply to ice ages also. The last ice age may have come to a sudden end in as little time as a few months - possibly even just 40 days! The resulting flooding would have been awesome. Certainly it would have been considerably more than most of us can possibly imagine.

If the last ice age was very severe, standing on the top of Hollerday Hill would not have been possible. The ice could have been as much as ten miles (16 km) thick.

The evidence for ice of this thickness is just across the Bristol Channel, only some twenty miles away.

In South Wales, the area around the Rhondda Valley is known for producing the best quality anthracite coal. Uniformitarian theory has it formed over many millions of years. Unfortunately it needs great pressure to convert wood to coal rather than a very long time. It is unlikely that conditions would have remained constant over such a long time. In fact, the pressure needed could have been created in a short time, could have lasted a relatively short time and then disappeared very quickly.

The pressure needed to form such good quality coal could be provided by a layer of ice some ten miles thick. We have little experience of ice forming in layers considerably thinner than this. To determine how long it would take for the ice layer to reach that thickness would be extremely difficult. That it could reach such a height is not impossible. As we have no experience of such ice forming it would be hard to say how long it would take to reach that height, but if there was a continuous snowfall, it could be as little as two years - or it could take a much longer time.

It remained in this state for many years, possibly several thousand years. We really have no idea how long the ice ages lasted. The only requirement is that it was there for long enough to provide sufficient pressure for the coal to form.

If we assume that such a layer did exist over South Wales, then while it would not necessarily be as thick as on the other side of the Channel, there would still have been a significantly thick layer of ice on the North Devon and Exmoor Coast. This ice would probably have extended to a lesser or greater depth over much of the current land mass of the Earth.

Dramatically, some ten thousand years ago, something happened to cause the ice to melt. It may have possibly been another asteroid strike. In this case as the result of an impact, it could have thrown very hot steam into the atmosphere.

In this scenario we now see the ice starting to melt very rapidly. The ten-mile thick layer of ice turning to water would have caused a trickle at first but it would soon have grown into a torrent of such proportions that have never been seen in recent times. The pressure behind this torrent could well have been sufficient to have broken through the already weakened wall at Lynmouth and then to have washed the debris out to sea.

In order to be able to sweep away a rock wall nearly some 1000 ft (300 m) in height together with anything supporting it, it must have been very big

Imagine torrents that would be rushing not just from the East and West Lyn rivers, but also from the River Severn and its tributaries, together with the rivers joining the Bristol Channel on both sides. The combined force could well have cleared a vast amount of debris from this. There would be no evidence that there ever had been a landmass here. All that would be left behind would be the stretch of water that we now call the Bristol Channel.

For a hint that such a thing did happen we only have to consider the stories of the flooding of Atlantis and also Noah's Ark. But that is another story …

geology/the_valley_of_rocks.txt · Last modified: 2011/06/03 20:07 (external edit)