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Breccia occurs within the sandstone unit in parts. It is similar to the Teignmouth Breccia. The of breccia above is a photograph of a small exposure in the walkway on the landward side of Coastbridge Bridge (just NE of Dawlish Station). This is close to the boundary between the Teignmouth Breccia Formation and the Dawlish Sandstone Formation. Thus it is not certain that it is breccia within the basal part of the Dawlish Sandstone Formation and it could be within the uppermost part of the Teignmouth Breccia Formation. The breccia in both these units is similar.
The sedimentary breccia is characterised here by a number of separate units, each of about 30cm thick or so. There is grading upwards, from small angular clasts in the lower part to laminated sand at the top. Not all the units are of significant lateral extent and some are lost within a few metres. It is clear that each graded unit is the result of a single and very rapid sedimentary process, i.e. a flash flood. Nothing was seen to suggest continuous sedimentation. The next flash flood deposit which follows a single example, does not in this case normally indicate any significant erosion. The situation is mainly one of progressive build-up of desert, flash-flood deposits.
TD-4 STRUCTURE
TD-4 STRUCTURE (start)
TD-4-1 Introduction
The sedimentology of the Teignmouth to Dawlish Coast is almost entirely concerned with Permian desert deposits. Desert breccias and desert aeolian sand are dominant. They can be seen in the cliffs and as reefs and ledges on the shore at low tide.
[text to be added]
TD-4 STRUCTURE continued
TD-4-2 Faulting
Many faults are recorded by the British Geological Survey in the 1976 edition of the BGS map - Newton Abbot 339. About 17 are shown along the cliffs between Teignmouth and Dawlish Warren. Relatively few are shown inland because they cannot be easily detected. The Permian strata do not always show conspicuous features or distinctive lithological differences at the surface that would enable the recognition of many of the numerous faults which much exist. The faults in the cliff generally trend NW-SE. They are not very obvious now in the coastal exposures except at Coryton Cove and at Smugglers Lane, Hole Head.
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The photograph above shows the very conspicuous effects of fault at the southern entrance of Kennaway Tunnel. The main fault plane is not very cleanly exposed, even though its location is obvious. In addition to the geological map, the fault is shown in a sketch of Coryton Cove on p. 109 of
Perkins (1971).
It is a normal fault, downthrowing to the south at abvout 35m and working against the dip (thereby extending the lateral outcrop). It is important in bringing up (on the north side the relatively hard breccia at Lea Mount. This can be seen in the cliffs and as resistant shore reefs. The sea stacks occur mainly where there is breccia and Cowhole Rock and the Old Maid Rock are both in a part of the Teignmouth Breccia downfaulted here.
The BGS map also shows a fault crossing at right-angles the obvious fault that can be seen in the cliff. The recess in the cliff is at the site of these faults and largely controlled by the obvious normal fault.
If the railway line and sea wall had not been there then the recess, proably a former cave would have cut back to the A379 Teignmouth Road. If the railway line closes but survives as a sea wall then no major change here is expected. A breakwater has deteorated at the northern part of Coryton's Cove, but the one in the southern part seem strong and resistant. There does not seem to be a record of the railway having been broken by storms in Coryton's Cove and there are no signs (in 2014) of major repair work here. Therefore it is likely to be a long time before the railway and sea-wall have broken through and the recess becomes active again. In other words the railway line has to be smashed up at Coryton's Cove before the main road on the cliff top is threatened. Even if this was to happen, rock armour could be placed on the beach to protect the cliff at the recess. The risk does not seem very high, at least in comparison to other places in the Dawlish region.
The fault shown above, in the left part of the image, is adjacent and just southwest of the Parson and Clerk rocks. It is not shown on the geological map of the area.
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TD-4 STRUCTURE (continued)
TD-4-3 Cretaceous Overstep
The Upper Greensand oversteps westward so as to lie on Permian strata in the Haldon Hills of Devon to the east of Dartmoor. An outlier of these Cretaceous strata is present at Holcombe Down, not far from Dawlish.
TD-5 COAST EROSION AND RAILWAY LINE PROBLEMS
TD-5 COAST EROSION AND RAILWAY PROBLEMS (start)
TD-5-1 Introduction
Sea Wall - Introduction
Kay (1991) has discussed in detail, and with excellent illustrations, the history of the railway line and sea wall, here and elsewhere between Teignmouth and Dawlish Warren. It was built by Isambard Kingdom Brunel in the mid 19th century, at a time when there was probably more beach sand (this is suggested at least for Dawlish, as shown by old photographs). The sea wall has quite a solid 2 feet (0.6 metres) thick masonery front, much of it consisting of Devonian limestone. However, this is resting on relatively soft sandstone and breccia bedrock which is easily eroded. Moreover, the railway line rests on an infill of sand and rubble. Kay mentions that whenever there is a prolonged period of easterly winds the sand cover at the foot of the wall is stripped away and the bedrock exposed to wave action. In the course of a couple of tides there can be undermining. The sea can make a hole in the bedrock underneath the wall's foundations, after which the waves wash out the weak infill material behind the wall. Thus at a particular site the may temporarily be suspended over a cavity.
Rockstone and Sea Lawn have had serious collapses. The wall at Smugglers' Lane, shown above, collapsed for a fair distance in 1855, and there was failure west of Smugglers' Lane in 1986. To attempt to solve this undermining problem a "toe" section of stone was built along the foot of the wall in the 1850s. Later timber groynes were constructed to try to hold the sand in place, and locally, as shown above, rock armour was tipped. For more on the topic of the sea wall and its failures see Kay (1991).
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The topic of the railway and the erosion of its trackway and walls is a well-known topic. It is not considered in detail here, other than in relation to coastal geology, coastal erosion and coastal geomorphology. Some brief historic matter is included, but there is much more information elsewhere, in many publications.
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TD-5 COAST EROSION AND RAILWAY PROBLEMS (continued)
TD-5-2 Railway History (brief)
TD-5 COAST EROSION AND RAILWAY PROBLEMS (continued)
TD-5-3 Tunnel Collapses
TD-5 COAST EROSION AND RAILWAY PROBLEMS
TD-5-4 Sea Wall Breaches - History of Breaches
(based on data from:
Kay (1991) Rails along the Sea Wall. )
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1846
. Near Breeches Rock, southwest of Dawlish.
1855
. Smugglers's Lane, Holcombe, near Parson's Tunnel (illustrated in an old etching)
1869
. San Remo Terrace, not far from the recent breach (but southwest).
1872-3
. Breaches just southwest of Rockstone Footbridge. A new wall was built in 1873.
1930
. Riviera Terrace. Close to the present breach of 2014. At the Sea Lawn Gap where the footway at the base of the sea ends. This footway comes from near Langstone Rock and gives some additional protection.
1986
. A short distance southwest of Smugglers' Lane.
2014. The new breach
at the Sea Lawn Gap, near Riviera Terrace, again and almost at the same site as the 1930 breach. This not only cut off the only railway line to the west, but also caused some damage to a house behind the railway and road. Work, involving spraying with concrete has been taking place since the collapse.
TD-5 COAST EROSION AND RAILWAY PROBLEMS
TD-5-5 Sea Wall Breaches - recent
[Breach in the Railway Line - 6th February 2014 and later repairs]
Location - Between Dawlish Railway Station and Langstone Rock
(at The Sea Lawn Gap, the former "Family Bathing Beach")
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The coast at Dawlish and elsewhere in region was severely attacked by several storms coming in from the Atlantic Ocean in January and February, 2014. There was a breach by storm waves of the main railway line into southwest England at the sea wall of Dawlish, at the Sea Lawn Gap, northeast of the railway station. Aerial and other photographs below show the exact site. It is a location of zero high-tide sand beach and is a major target of the sea at Dawlish. Go to Google Earth, Dawlish, see aerial photograph for April 2013. This is also held offline but is not reproduced on the web without obscuring, for copyright reasons
[clear version is:
/Dawlish-Permian/14DWL-Offline-Sea-View-Storm-2013.jpg].
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So there is nothing suprising about the breach. It is the fourth to have taken place between Dawlish Railway Station and Rockstone Footbridge. The list of known breaches of the seawall and railway line between Dawlish Warren and Teignmouth is given in a list further below: List of Breaches, Teignmouth to Dawlish.
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Relevent extract on implications of closure of the railway line because of breaching by the sea; from Kingdom (2008)
.......the sea itself, which continues, relentlessly, to erode the soft sandstone cliffs and shore [of Dawlish]. It is in fact for this very reason that throughout the 160-plus years of its existence the sea wall has seldom been out of the news, especially in recent times with the onset of global warming and rising sea levels.
At this point, it is perhaps, interesting to reflect that in the late 1930s no less than three alternative inland deviations for the railway line were proposed and that even an Act of Parliament was passed. However, escalating costs and the onset of the Second World War put paid to this venture and the status quo remains to this day. This, in turn, means that if the sea wall did succumb to the elements and the line had to be closed the effect on the local economy of places such as the seaside towns of Teignmouth and Dawlish, not to mention that of the South West as a whole, would be catastropic. It only remains for me to say, therefore, that whatever the cost of keeping it open, this vital West Country link and the truly scenic gem into which it is set must be preserved for the well-being and enjoyment of both the present and future generations alike. A.K. Kingdom, March 2008.
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Thus the sea-wall fails at irregular intervals, usually separated by about a decade or several decades. There is no major deposit of beach sand remaining in The Sea Lawn Gap Area (Sea Lawn Terrace and Riviera Terrace etc.). The matter is not helped by the fact that even the lower footpath, a narrow concrete platform at the base of the sea wall, is absent there. Suprisingly, too, there is housing closer to the sea here than almost anywhere else in the region. Indeed some house seem to have been built here, very close to the sea wall and railway even in the quite recent past.
This part of the coast seems to have been a subject of optimism or lack of serious concern since the days of Isambard Kingdom Brunel. Of course, as long as there is a railway there and there an no alternative route around Okehampton or elsewhere, it will presumably be maintained as a sea-wall, even in spite of global warming and potential sea-level rise. The present damage should be repaired within a few weeks. It is not known whether there are any plans to place major rock armour in front. That has happened long ago at erosion risk areas, adjacent to the railway line at Dawlish Warren and at Smugglers' Lane, Holcombe. If rock armour is not added, then perhaps the sea wall and railway line will be broken again sooner or later.
Of course the succession of storms in January and February, 2014 not only damaged this area, but also caused major effects elsewhere. There was very serious flooding in various parts of England, particularly in the Somerset Levels and on parts of the Thames floodplain. On the south coast there was major damage to the Chesil Beach
(see the Chesil Beach Storms Webpage.)and elsewhere.
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In Pictures: Dawlish Restoration - BBC New Report Online. Click this link to go to the BBC slide show (which gives sharing permission).
(Note that the first illustration, shown below, is not of the breach at Sea Lawn Gap, N.E. of Dawlish, but of additional, lesser, damage that took place southwest of the Smugglers Lane area, Holcombe, i.e. on the south side of the Parson and Clerk rock etc. Images of the Sea Lawn Gap breach follow.)
See this particular slide show, for good clear photographs of repair work on the breach of the railway line at Dawlish and on repair work between Teignmouth and Hole Head.
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The beach in front of the railway line and sea wall at Dawlish is shown above as it was in 1899. The it was fairly wide, especially in the area near the Station. It is likely that a fairly high beach probably existed most of the way along in front of the railway line, although probably narrow in places. Since then it has narrowed; groynes have been constructed, and then from time to time the line has been breached. The latest occurrence was in early 2014 and this is discussed here.
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Go also to the photographs of damage to the railway line at the Sea Lawn Gap (one example is given below) in the following newspaper :
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WESTERN MORNING NEWS - (click this link) .
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Above is an older photograph from the year 2008. Notice that there is an absence of beach at high tide in the area where serious storm damage occurred later, in early 2014.
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In the bay at Dawlish there is movement of beach shingle and sand towards Langstone Rock to the northeast. This is because of storm waves coming from the southwest. The beach is at its maximum width adjacent to and on the southwest side of Langstone Rock. A major groyne at Langstone Rock prevents movement of shingle away towards Dawlish Warren. Beyond the rock to the northeast there is no beach for a stretch, but here rock armour has been added from time to time. Some of the oldest rock armour is Dartmoor Granite, and larvikite has been added in recent times. However, rock armour does not seem to have been used on any large scale in front of the present problem stretch where there is a narrow to absent beach, i.e. the region of the breakthrough in the railway line (and damage to houses). Rock armour has long been used at Holcombe in a stretch near the tunnel, because of erosion risk.
TD-5 COAST EROSION AND RAILWAY PROBLEMS
TD-5-6 Railway - The Future? (Alternative Line)
Regarding the future of the railway line at Dawlish and Teignmouth, the following brief information was given on the 1st November 2014 in the Exeter Express and Echo of Exeter City Council.
Alternative Rail Line Avoiding Dawlish Flood Hotspot Must Be Built,
- says Transport Minister (posted October 31st 2014)
A new inland rail route away from the Plymouth region must be identified as a long-term solution to the Dawlish flooding problems, a senior Government minister has admitted. Transport minister Patrick McLoughlin has been on a fact-finding tour of the Westcountry in the wake of last winter's storms. The minister, speaking en-route from Newton Abbot to Paignton, said: “We all have in our minds the images of Dawlish as it was being battered by last year’s storms. There have been some other complications at Dawlish, not least the cliff face slippage. We are looking at the resilience for the area."
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Present Writer's Comments re Coastal Erosion:
(Just some brief informal discussion, given without full background knowledge other than geological - go to other sources for serious considerations!)
Rerouting the railway line inland, seems inevitable with slowly rising sea-level, an apparent increase in storms, and numerous fast, precisely-timed trains. They cannot nowadays be held up or stopped for long periods by broken sea walls or fallen cliffs.
If the railway is actually closed (and of course, it may not be) then the problem of maintaining the sea wall is a problem that may or may not be completely solved. There might be a completely artificial solution, but that would be at great cost. It is not a geological matter and any possible scheme is unknown so it is not discussed in any detail here. The return of the coast to a natural Devon coastline is considered only very briefly below.
If the coast is left to become more natural there will probably be deeper embayments in the centres of bays, particularly where there is no protective beach sand. It would be surprising if the main railway line breach areas did not retreat unless they were specially protected and, of course, they may be (with rock armour, concrete, beach sand, groynes etc?)
Cliffs (many now graded back) will naturally steepen to more normal profiles as the lower parts are eroded. Many cliff falls will, of course, take place. Small embayments and headlands may develop. Obviously the main places where the sea has already damaged the railway line are likely to be places of retreat. The railway line is, at least for some parts, unnaturally straight and that deeper bays are more natural in this area, as elsewhere. Examine the Torquay and Dawlish Ordnance Survey Map, 110, 1:25,000 scale. See also the BGS geological map, Sheet 339.
The coast between Langstone Rock, Dawlish and the southern end of Teignmouth is relatively straight and controlled by the railway line except in the Holcombe area (Lea Mount, Coryton, Hole Head etc). Contrast this with the coast south of the Teign estuary, between Shaldon (The Ness) and Watcombe Head. A similar Permian stratal unit, the Teignmouth Breccia is the bedrock here. This natural southern coast, however, is not straight and there are many embayments. That is natural and a rather similar coast may in the long term develop at what are now straight parts of the coast between Teignmouth and Dawlish. The only very straight (or gently curved) coast in the region is at Budleigh Salterton. There is a good reason for that; it is the abundance of resistance beach material, the abundant large and hard, rounded pebbles derived from the Budleigh Salterton pebble bed. The relative lack of appropriate beach material at the Teignmouth - Dawlish railway coasts is a major problem, but not the only one. Note that the cliffs vary in lithology from breccia to (soft) sandstone from place to place and there are many faults present. An old illustration shows that before the railway the coast at Dawlish was not straight (and had, perhaps an old, small headland at the Coastguard Station).
The problem is fairly obvious. What will happen is not clear. Will the railway wall be maintained indefinately? Will major beach replenishment take place? Will huge quantities of rock armour be placed in front of vulnerable areas? Will new groynes be built? ]
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Buildings at Dawlish Seaward of the Original Cliff-Line.
Dawlish differs from some other coastal resorts (but is similar to some), by the fact that some of the building adjacent to the sea are in front of the original, historic, cliff line.
Particularly see the very interesting image of 18th Century Dawlish in:
Mitchell Family Online.
It is indicated from this (and from visual observation at the location) that some buildings at Dawlish may be seaward of the original cliff line, the former sea-erosion limit. Anything so situated might require the persistance of a safe strong wall to the seaward side, if the location is one of erosion or sediment depletion. The matter is intentionally not discussed further but the implications and comparisons elsewhere will probably be obvious to the reader.
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TD-6 GEOLOGICAL LOCATIONS - TEIGNMOUTH TO DAWLISH
TD-6 GEOLOGICAL LOCATIONS
TD-6-1 Introduction
The following locations are briefly discussed in order from the southeast at Teignmouth to the northwest at Langstone Rock. Some of these are easily reached by car and on foot. Others, particularly at and around Hole Head can only be accessed by boat. There is not even a complete coastal footpath at the headland.
TD-6 GEOLOGICAL LOCATIONS
TD-6-2 South of Teignmouth (Shaldon, The Ness)
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TD-6 GEOLOGICAL LOCATIONS
TD-6-3 Teignmouth
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Teignmouth Pier was extensively damaged in the storm of February 2014, that so affected the railway line. The pier lost much of its flooring. By the summer it had been repaired again. The end part is shown here as it was on the 29th September 2014.
TD-6 GEOLOGICAL LOCATIONS
TD-6-4 Teignmouth to Sprey Point
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Hard beds of breccia in the Permian strata form ledges or reefs on the beach at low tide. These occur in places from the northern part of Teignmouth town to Smuggler's Lane, Holcombe. The beach sand at the town of Teignmouth seems to moves southward by longshore drift, that is towards the estuary. Groynes have been used to try to trap the sand but most of these are worn and damages. Further to the northeast the movement seems limited in rate.
For more information on sand movement see:
SCOPAC Report - Hope's Nose to Holcombe, Devon.
Loss of sediment by reflective scour (washed back by storm waves) is an issue. There is no resupply because of the seawall and railway. Beach can only be lost, not gained here.
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The cliffs between Teignmouth and Smugglers Lane, Dawlish are now in rather disappointing state. The Teignmouth Breccia does not outcrop as a hard, resistant unit, until the Hole Head promontory at Smugglers Lane (and northward) is reached. At the back of the railway line the Teignmouth Breccia is rather degraded and easily slumps as landslides. Most of it is now covered with vegetation. These cliff have been artificially sloped to some extent over the last 150 years, but particularly in the 1920s. Thus the exposures are poor and they cannot be reached because of the railway line.
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TD-6 GEOLOGICAL LOCATIONS
TD-6-5 Sprey Point to Smugglers Lane
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The cliffs at the back of the railway between Smugglers Lane (Parson Tunnel south end) and Sprey Point are potentially weak, as can be seen from the promenade and on aerial photographs. They do not show hard projecting Teignmouth Breccia, even though they are stratigraphically within Teignmouth Breccia Formation. Aerial photographs do not show ridges or rock ledges in the sea for most of this stretch (although there are some south of the bridge at Smugglers Lane). The cliff are steep, of relatively soft strata, not properly exposed and not accessible. There have been problems with the cliffs further south at Sprey Point and in 1922 there was much artificial sloping of the cliffs here to reduce risk of cliff falls (see photograph on p. 55 of
Kay, 1991). Ropes for workers descending were left on the cliffs. More recently, in 1986, there was a breach of the sea wall, somewhat north of halfway between Sprey Point and Smugglers Lane Viaduct (where there was an 1855 breach (See Kay).
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TD-6 GEOLOGICAL LOCATIONS
TD-6-6 Hole Head, Holcombe - Southeastern Vertical Cliff near Smugglers Lane Viaduct - General
(OS map ref. SX 957747)
(Accessible at low tide)
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Above is an aerial photograph, courtesy of the Channel Coastal Observatory, that shows the general coastal features of Hole Head. The section which follows next is concerned with the southwestern, cliff, a vertical wall, near the Smugglers Lane Viaduct and the southern entrance of the Parson Tunnel. Here, where the railway line passes into the rock, the promenade and sea wall from Teignmouth end. The other, parts of Hole Head, inaccessible from the shore are discussed separately below in the following section.
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A good cliff section of typical Teignmouth Breccias can be seen at Hole Head near Smuggler's Lane, Holcombe (SX 957747). This can be reached by walking along the sea wall alongside the railway from Teignmouth (park car at NW end of sea front road) or from Smugglers Lane, accessible from the Dawlish to Teignmouth Road (A379). It is only possible to walk right up to the cliff at low tide, because the promenade ends a short distance from it and at high tide the sea washes in under the viaduct.
[In October 2014 and probably much earlier, no vehicle access was allowed down Smugglers Lane because it was in use for vehicles and machines for civil engineering work on the railway line and sea wall. This was to repair severe damage that took place in the storms of early 2014. It was easy, though, to walk down the lane to the sea-wall, after parking a car in a nearby road at Holcombe.]
The Permian breccia is well-exposed in the cliff here. There is some very coarse breccia in the lowest few metres above the low-tide beach. Higher up the strata are much like those of other parts of Hole Head and north-east to Lea Mount, Dawlish.
The Teignmouth Breccia is characterised by fragments of
quartzite, porphyry, hornfels and a distinctive flesh-pink feldspar, thought to come from a short-lived explosive volcanic phase in the north-eastern part of Dartmoor
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Durrance and Laming (1982) commented that there are several well-marked sand dyke structures and some porphyritic rhyolite boulders or quartz porphyry (see photograph above). This breccia does not have an abundance of limestone clasts as in the breccia at The Ness, Shaldon. The breccia horizons alternate with thin sand beds. The strata are almost horizontal. The harder breccia beds project in the seaward (southeast-facing) cliff, where, from time to time, strong southeasterly waves and winds strike the coast.
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The large clasts are very angular and only show a little wear on the edges. The corners are often almost intact. The boulders cannot have travelled very far or very often. However, there are many diverse rock types. Most notable are occasional clasts of quartz porphry or "elvan" (local term). These are brownish, more rounded and with phenocrysts of quartz and feldpar. They may also contain gas bubbles. The rock type occurs fairly commonly around the Dartmoor Granite, even as close as Christow, up the Teign valley (although the transport direction does not accord with this particular case). Perhaps the quartz porphyry clasts have been rounded before the flash-flood erosion and transport that broke up the general strata into angular clasts. The matter is a little puzzling though.
Particularly interesting are the small, red, mud-filled channels. The deposits, of mud or sandy mud, are in general of flash-flood origin. The mud deposits might be compared to recent flash-flood mud sediments of the Colorado River area. See:
Geotripper - Gary Hayes - Into the Great Unknown: We Interrupt This Scenery For a Very Recent Flash Flood and a Biological Disaster - Little Nankoweap Creek.
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TD-6 GEOLOGICAL LOCATIONS
TD-6-6a Smugglers Lane - Hole Head - Sedimentary Structures:
Natural Hydraulic Fracturing - Water Escape - Sand Dykes
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A particularly interesting feature of the Teignmouth Breccia in the Hole Head area, Dawlish, is that these Permian strata have been naturally "fracked", i.e. hydraulically fractured by water pressure. The sand-filled fracture system can be seen particularly well at two places, Coryton Cove and the Smugglers Lane cliff section. There is an indication that it is probably present at other less accessible places, such as Horse Rocks. The high water pressures result from rapid sedimentation and thus rapid increase in sediment load. This is not surprising at Smugglers Lane, where there is a thick sequence of breccia above. At northern Coryton Cove, a limited thickness of breccia is covered by aeolian, dune sands. Therefore a great weight of breccia was not rapid added at that locality.
The sand dykes at Smugglers Lane, in particular, seem to indicate downward injection of sand. The sedimentary structures at Coryton Cove could be in either direction, and it is not clear.
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The image shown below is with regard to Coryton Cove, where similar water escape structure occurred. It is provided again here for comparison.
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The vertical cliff, parallel with a fault plane at the southern end of the Parson Tunnel, and adjacent to Smugglers Lane, is very good for showing the sedimentary structures mentioned above. Note that low tide is needed for access. Water-escape or dewatering has involved upward injection of water and sand into fractures. Thus small, vertical, sand dykes or clastic dykes were produced. These were long ago reported by Durrance and Laming, 1982, p. 176. As mentioned above, similar, but more conspicuous, sandstone dykes can be seen in a particular bed in the cliff on the northern side of Coryton Cove (at the foot of Lea Mount).
Go also to:
Dawlish Warren and Langstone Rock webpage. See:
"Langstone Rock, Sand Liquefaction Structures". One of the images from that webpage is reproduced below, for comparison.
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See also
Hurst et al. (2003)
for discussion of sand injectives and for further references, although their paper is mostly concerned with larger structures.
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TD-6 GEOLOGICAL LOCATIONS
TD-6-6b Smugglers Lane - Hole Head:
Rock Armour
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There is much rock armour near the southern end of the Parson Tunnel, as shown in the photograph. The tipping of this commenced in 1905 and took place again from time to time (Kay, 1991). This rock armour is quite interesting. It includes several varieties of granite, including some with numerous megacrysts of felspars and others without. The lower of these rocks are abraded by the sand and show clean faces. At high tide you can walk along the sea wall towards the headland, but you cannot get close to the rock face. The stretch of coast between Teignmouth and this locality is disappointing geologically because the railway prevents access and the cliffs have been sloped and are very much vegetated. There are only small exposures of red breccia or sandstone.
TD-6 GEOLOGICAL LOCATIONS
TD-6-6c Hole Head, Holcombe - Seaward - Collapsed Southern Corner
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The above photograph of the collapsed corner was taken from the landslide area near Sprey Point, at least half a kilometre away. As a result this image is extremely compressed and the lateral extent of the feature is not shown. Go to an aerial photograph of the Channel Coastal Observatory or of Google Earth to see the lateral extent of the area of fallen rock. There are many large blocks of Teignmouth Breccia on the shore, as can be seen in the photograph given here.
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The particular stretch is just south of three large caves at Hole Head. It is possible that it represents a collapsed fourth cave, but it has not been studied closely enough to be sure of this. This southern part of Hole Head is also a faulted area, with the main Smugglers Lane Fault and at least one parallel fault present. Between the fault planes there has been some local failure of the cliff. Large blocks, which have obviously come from the cliff, are present on the shore beneath. There are also debris cones, one of which has growing tree that seems to be a small pine (not natural to the area).
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TD-6 GEOLOGICAL LOCATIONS
TD-6-6d Hole Head, Holcombe - The Three Caves
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North of the collapsed stretch at Hole Head, there are three large caves. The location of these is shown on the aerial photograph below.
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TD-6 GEOLOGICAL LOCATIONS
TD-6-6e Hole Head, Holcombe - Parson and Clerk Rock
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The rugged seaward cliffs of Hole Head are now discussed. These are not accessible from the shore even at low tide. There is private property above, no cliff walk and no access down the cliff. They can be seen by boat.
The Parson and Clerk Rocks of Permian, Teignmouth breccia, have been modified by the sea over the years. The outer rock, Shag Rock, lost its uppermost part in a storm in January 2003. Compare the old illustration, shown on the notice board, with the modern photograph.
Incidently, there is a Parson and Clerk legend, recounted in an article in "Holcombe Jottings" by the Holcombe Residents Association. This is a story of a parson and clerk arriving by horseback at a devilish inn and being turned to stone!
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At the foot of the seaward cliff there are many large blocks on the shore adjacent to a vertical or near-vertical cliff with large caves. Of course this headland is eroding, and the process is partly undercutting. Blocks from the projecting Teignmouth Breccia beds to lead to an accumulation of large angular blocks on the shore, as shown in the aerial photograph. Failure occurring at intervals in this region is also shown by the loss of the uppermost part of the offshore Shag Rock. Coastal retreat of the headland, however, cannot be very rapid though, or features such as the Parson Rock would not have survived.
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Hole Head and Parson and Clerk Rocks - Sedimentary Structures
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Compare these interesting sedimentary structures to those in the
Permian Torbay Breccia at Corbyn's Head. See, for example, the photograph below.
Similar mud layers, but less well-developed are present in the Permian, Torbay breccia at Corbyn's Head, Torquay. The examples at Hole Head are less well-developed than at Corbyn's Head (which is in a facies of rather finer sediment). There is no doubt that these are of similar origin.
See particularly Brookfield (2000) for discussion of similar mud layers in Permian breccias of Scotland as a result of the temporary development of small ponds on pediment breccia and sand deposits. Such an origin in a small and temporary ponds is very likely for the thin mud deposits in the Permian breccias and sands both at Torquay and at Hole Head.
Shag Rock lies about 150 metres offshore from Hole Head. It is a distinctive and isolated stack and should not be confused with the Parson and Clerk Rock which is adjacent to the cliff. It is the only offshore rock here. On top there may be birds of the Cormorant family, using it a resting place from fishing the local water.
TD-6 GEOLOGICAL LOCATIONS
TD-6-7 Shell Cove
(sometimes marked on maps as Horse Cove)
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At Shell Cove and adjacent area between Dawlish and Holcombe, the railway line passes through some small tunnels at small headlands. The beach at Shell Cove is surprisingly well-developed, in contrast to the area north of Dawlish. Substantial breakwaters give it protection, and presumably the sand cannot escape easily to the north because of the promontory of Horse Rocks (which has a small connecting breakwater). It is clear that these rocks are relics of a small headland, which has only recently been broken through. It is surprising that the breakwater does not directly connect the two sea stacks.
TD-6 GEOLOGICAL LOCATIONS
TD-6-8 Horse Rocks
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The Horse Rocks are eroded sea stacks in the Permian, Teignmouth Breccia. They consist of well-bedded breccias of a relatively finer grained type, and with a general northerly dip. They are similar to the breccias seen in the northern cliffs of Coryton's Cove.
The outer stack has now lost its topmost part, which is shown in older photographs. These stacks are adjacent to a fault, that might have affected cementation or erosion. The stacks are not accessible on foot along the shore, even at low tide. They are visible at a moderate distance from Coryton's Cove, Dawlish, looking south. They can also be seen, on the other side, from the coastal footpath which descends into a valley above Shell Cove.
TD-6 GEOLOGICAL LOCATIONS
TD-6-9 Horse Cove (i.e. north of Horse Rocks)
There is a nomenclature problem regarding the coves on either side of Horse Rocks. On old maps Horse Cove is shown to the north of Horse Rocks. Recent Ordnance Survey and Geological Survey maps show "Horse Cove" at about the location of Shell Cove.
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There was a major rock fall in the high cliff of the Teignmouth Breccia just north of Horse Rocks in 2007. A newspaper cutting recording this is shown above. The location seems to be Horse Cove in the old sense of the location name.
TD-6 GEOLOGICAL LOCATIONS
TD-6-10 Coryton's Cove (or Coryton Cove) - Main Part
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Coryton's Cove or Corytons Cove (map reference SX 961761) is notable for a large Permian sand dune over the top of desert alluvial breccias. The exposures are not ideal now because of growth of vegetation on the old cliffs.
The cove can be approached from Beach Road over the railway footbridge, or by cliff paths. It is only a short distance from a car parking area at the southern end of the main Dawlish seafront, near the railway tunnel. The sand dune has been estimated as having been about 60 feet or 18 metres high (Perkins, 1971). Local measurements of cross-bedding indicate an apparent wind direction from the southeast. However there has been rotation of the British region since then.
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TD-6 GEOLOGICAL LOCATIONS
TD-6-10a Coryton's Cove to Lea Mount (i.e. northern cliffs of Coryton's)
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There are good exposures, mainly of breccia in the cliff at the northern part of Coryton's Cove and the southern end of the Lea Mount promontory. This short stretch of cliff that is effectively the southeastern side of Lea Mount. The sand dune cliff exposures of Coryton's Cove discussed above cannot be directly reached because of the sea wall and railway line. Here, in this exposure of the Teignmouth Breccia, various stratal details can be readily accessed and seen clearly.
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The next photograph, taken on a different, earlier, occasion (note variation in amount of grass on the cliff), shows the same place as above in more detail. It is a closer view, with water-escape structures emphasised to some extent.
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This is the type locality for Coryton Breccias, which are shown in the photographs. According to Durrance and Laming (1982), the breccias are of quartzite-porphyry-aureole-feldspar type.
Narrow sand dykes, probably formed as water-escape structures can be clearly seen (in photographs above) in the breccia here. They are particularly developed in a more sandy bed of the breccia, with less large clasts. They are not just sand infills of joints because they do not have large clasts at the base (i.e. stones have not fallen in). These sand dykes are peculiar because fissures from them continue upward for some distance. They seem to be associated with major joints that are inclined from the vertical. These do not seem to be faults because there is no major vertical displacement (minute displacement is possible in at least one case.
The sand dykes have central fill of slightly different colour and presumably of slightly different composition. Thus they seem to be multiphase. They are very different from the short upward sand dykes in Exe Breccia at Langstone Point. Those younger ones are very short and wide and end upwards quite abruptly.
Perhaps, and this is only speculative, the Coryton sand dykes are quite late, post some burial and result from reactivation of an unstable sand-rich breccia bed. It might be the result of tectonism after sedimentation of a larger stratigraphical unit.
TD-6 GEOLOGICAL LOCATIONS
TD-6-11 Lea Mount, Dawlish (and Cowstone Rock) and rock fall accident.
This is a hill and promontory at the southeastern end of the Dawlish Sea Front, and it is directly north of Coryton's Cove (and the southern cliffs of the Mount can be regarded as the northern cliffs of Coryton's Cove). It is of very easy access from the central beach area and station of Dawlish.
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The east-facing cliff at Lea Mount is probably an artificial cut. At the time of an accident referred to below there was a more acute promontory here. The cliff has been squared-off and promenade and a cliff footpath established, so it is not entirely natural. The details of the Teignmouth Breccia do not show well. Exposures up the inclined footpath show that the aeolian sandstone lies above. There is a small but very exposure of the junction between the two lithologies.
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Accident at Lea Mount in 1885
In 1885, before the sea wall and promenade was built here, there was a walking route close to the cliff under an overhang. This was probably similar to the overhang in the Bridport Sands at
Burton Bradstock at present (nearby which there has also been a fatality beneath sandstone cliffs because of a rock fall).
See:
1885: Dawlish Death Trap. by R.G. 2011. This writer draws attention to the following paragraph:
"Lea Mount owes its formal, straight-cut outline to the anxieties tha followed the falling of a portion of the cliff on August 29th, 1885, when over 50 tons of rock buried a party of seven women and children, killing three of them. To prevent further accidents, all overhanging portions were cut away."
"On Saturday, August 29th 1885 at around noon, six members of the family and household of Dowager Lady Sawle were preparing for a picnic lunch beneath the overhang, when a large mass of rock (estimated 50 - 150 tons) split from the cliff above them. They had a moment's warning from a seventh party member, Ellie Watson, who was standing nearer the sea and saw the start of the collapse. Three ran towards the cliff, and were buried and killed instantly: nine year old Violet Mary Watson; Mary Radford (lady's maid to Lady Sawle) and Elizabeth Keen (nurse to the Watson children). Three who ran towards the sea, a Miss Watts, Miss Matthews, and Johnny Watson, survived, but were seriously injured. Only Ellie Watson was unhurt."
A very similar rock fall of sandstone occurred at Burton Cliff in 2012.
Fatal rock fall from sandstone cliffs at Burton Bradstock, 2012. With regard to Dawlish and Teignmouth, in general, the railway line, associated promenades, seawalls and breakwaters prevent cliff falls from affecting walkers on the coast. If the railway line should be closed and removed, there may not be an immediate increase in risk from rock fall. Later, if and when the promenade and railway track route deteriorates, then the risk will progressively increase. Rising sea level, and perhaps an increase in storms will further cause a greater chance of accident. Rock falls are actually very common here and the record of them goes back to the days of Brunel, and is shown in old illustrations. Strangely, the railway line is a safety factor. The chance of accidents at a particular cliff is also, of course, dependent upon the amount of visitors to such a cliff. There is much more risk of an accident at popular sites where people frequently walk, than at remote and difficult coasts. These comments are not to suggest that it is a good idea to have a railway line in front of a cliff, but simply that removal of the line and removal of maintenance work could, perhaps, increase fatality risk. No proof of this is given here and, in any case, it is not known at the present whether the line will be closed at all or what measures will be taken if it is. Rock fall risk is just another factor to be considered.
The Teignmouth-Dawlish cliffs are fundamentally somewhat similar to those at Burton Bradstock, but are graded back and maintained in relaive safety at present. They are much more heavily used by walkers than are the more remote Burton Cliff.
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Martian Type of Breccias at Dawlish
The Permian Breccias of Dawlish have similarities to desert breccias on the surface of the planet Mars. Much of the land area of the Earth was of rather Martian ("red planet") type during the Permian, although obviously there was some, but limited, life around in the hot desert. Good, red, Permian breccias are easily seen at Lea Mount, Coryton's Cove and at other places (such as Langstone Rock) in the Dawlish area.
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TD-6 GEOLOGICAL LOCATIONS
TD-6-12 Boat Cove and Kennaway Tunnel
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At the foot of Lea Mount, at the southern end of the main Dawlish sea front, is the small recess of Boat Cove. This little embayment is sheltered by Lea Mount and the Cowhole Rock from southern storm waves. In addition it has an artificial sea wall on the eastern side. It is probably the only safe place at main Dawlish sea-front where boats can safely come ashore. The Teignmouth Breccia can be seen in the Cowhole Rock and it has low dip towards the north. There is some beach here with both sand and pebbles.
If I understand the online accounts correctly, this is Cowhole Rock and the Old Maid Rock was on the ledges, offshore to the southeast. A stump which is probably the remains of it can still be seen, but the upper portion of the rock, at that time unstable, was removed in 1888
(See Wayland Wordsmith, Discourser on the Jurassic Coast, Friday 22nd January 2010, online at http://waylandwordsmith.blogspot)
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TD-6 GEOLOGICAL LOCATIONS
TD-6-13 Dawlish Sea Front
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The Marine Parade area at the south side of Dawlish is a notorious place for the soaking of trains by seawater. The "new" sea wall was built here in 1902 without any wave reflection coping at the top (present elsewhere on this stretch of coast). Large quantities of water are thrown over track and trains in bad weather causing washouts of railway track ballast (Kay, 1991, see photo on p.52). As shown there is spray even in relatively quiet conditions.
TD-6 GEOLOGICAL LOCATIONS
TD-6-14 Dawlish Station
TD-6 GEOLOGICAL LOCATIONS
TD-6-15 Coast Guard Station to Langstone Rock
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The coastline from Dawlish to Langstone Rock (near Dawlish Warren) has been greatly changed by the construction of the railway line for the Great Western Railway. Previously, this stetch consisted of well-exposed cliffs of Permian, wind-blown, sandstone, the Dawlish Sands. These poorly lithified sand deposits supplied sandy to the beach. When the railway track was constructed it prevented erosion of sand from the cliffs. It also prevented public access to most of the cliffs between Dawlish and Langstone Rock. The railway company sloped the cliff back, particularly at the top. During the steam engine era, cliff vegetation was purposely limited to prevent cliff fires. Now the vegetation grows unhindered and a large proportion of the cliff exposures have now been covered, particularly by the Hottentot Fig, a alien plant which flourishes in the mild climate here.
The railway line from Exeter to the southwest uses the coast here, seaward of the original cliffs. It runs along a sea wall from Dawlish Warren to Dawlish and on to Teignmouth. It was designed and built by the great engineer, Isambard Kingdom Brunel, who intended to reduce costs by using the sea-front as a relatively easy, and a scenically attractive, route. As many as 2000 navies were involved in 1845-1846 in excavating tunnels, blasting cliffs, building the sea wall, and constructing the line (Kay, 1991). It was opened in 1846. It was initially broad gauge and operated by an "atmospheric" (vacuum pipe) system without locomotives. Later it was changed to steam engines and, eventually, standard gauge.
Brunel's optimistic plan was that breakwaters would cause the accumlation of beach sand, and that the sea wall would not be touched by the sea except under severe gale conditions (Kay, 1991). However, the sea wall has long been under attack, particularly in the winter of 1872/1873, when there were major breaches. There was discussion about building a new line inland.
The sea wall has undergone much repair and rebuilding but it has no wave-reflecting curve. Sea spray and overwash frequently damages the line and lands heavily on trains. With global warming now causing a relatively rapid sea-level rise it is recognised that in within about 50 years this line may be doomed. There is at present (2008) consideration taking place of a scheme for the future of using a railway line from Okehampton to Plymouth ( BBC - News - Sea level rise means rail rethink).
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[Dawlish Sandstone Formation]
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TD-6 GEOLOGICAL LOCATIONS
TD-6-16 Sand Beach Southwest of Langstone Rock
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Former Environmental Science students from Southampton University are shown here investigating the beach and coastal processes just to the soutwest of Langstone Rock and its groyne or breakwater in 2008.
TD-6 GEOLOGICAL LOCATIONS
TD-6-17 Langstone Rock
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[END OF NEW RE-ORGANISED SECTION]
For:
LANGSTONE ROCK
Go to: Dawlish Warren Sand Spit, Devon
ACKNOWLEDGEMENTS
New images of the cliffs at Holcombe and the Parson and Clerk rocks have been added to this webpage in 2013, thanks to the kindness of Peter Hawtin and Ian Hawtin who taken excellent photographic records of the strata from the shore and the sea. I am very much obliged to them for their contributions. I am very grateful to the staff and students of the Environmental Science section of the School of Civil Engineering and the Environment, Southampton University. Many of the photographs in this webpage have been taken during Southampton University, field courses, based at Exeter University, although there has been later updating. I particularly thank Dr. Malcolm Hudson, Dr. Paul Kemp, Dr. Simon Kemp, Dr. John Jones, Dr. Elizabeth Williams and other members of staff of Southampton University. Many students have kindly agreed to allow photographs of themselves taken during fieldwork to be used on the internet. I am very grateful to the staff of the Dawlish Warren Nature Reserve for explaining the features of the area during various student field courses in the past.
I am very grateful to the
The Channel Coastal Observatory , National Oceanography Centre, Southampton University, Southampton, for permission to use their aerial photographs. I thank Katherine Jawed for kindly allowing me to use two of her photographs of sedimentary structures in the Permian breccias of Coryton's Cove.
REFERENCES AND SELECT BIBLIOGRAPHY
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BBC News
. 2008. Sea level rise means rail rethink.
Website: - BBC News. 2008. Sea level rise means rail rethink..
Fears about sea level rises swamping the existing main railway route to the South West mean the old line between Okehampton and Plymouth may be revived. The current line runs along Dawlish seafront and trains can be cancelled and delayed during heavy storms as waves break over the line.
Long-term concerns about the line mean that the inland route, closed in the 1960s, may have to be reopened. A report for train operators says it could happen within the next 50 years.
Faster route: Transport consultant Jim Steer, who wrote the report for the Association of Train Operating Companies, said: "I think it's important not to get too romantic about reinstating the railway lines that Dr Beeching closed in the 1960s.
"Instead we should looking at the real transport needs and in this case it is a faster route into Cornwall and a route that avoids the risk factor around the coastal route that are the motivations."
Developers are already trying to raise £10m to reopen part of the route, from Tavistock to Plymouth. The 5.5 mile (9km) Drake line was closed off at Bere Alston in 1968.
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Brookfield, M.E. 2000. Temporary Desert Lake Deposits, Lower Permian (Rotliegendes) Southern Scotland, U.K.
Chapter 4, pp. 67-73 in: Gierlowski-Kordesch, E.H. and Kelts, F.R. 2000. Lake Basins Through Space and Time. AAPG Studies in Geology. No. 46. The American Association of Petroleum Geologists. Edited by: Elizabeth H. Gierlowski-Kordesch and Kerry R. Kelts. Paper by M.E. Brookfield, Land Resource Science, Guelph University, Guelph, Ontario, Canada.
[The descriptions of the alluvial fan and pediment ponds relates well to the examples of such pond deposits in the Permian breccias at Corbyn's Head, Torquay (see the Torquay webpage) and one present at Hole Head, near the Parson and Clerk rocks, Holcombe, near Dawlish. See photograph above.]
Relevant extracts from the Introduction etc:
During the Late Carboniferous to Early Permian, a large lowland desert developed over the whole of southern Scotland.
Several desert basins were eroded into softer Carboniferous sediments preserved in postdepositional grabens within the lower Palaeozoic Southerh Uplands massif (Figure 1) (Brookfield, 1978, 1980; Glennie, 1982)......
Northwesterly directed faulting then formed the isolated graben of the Moffat, Lochmaben, and Dumfries basins to the south and east. In these grabens marginal alluvial fan sequences are dominated by immature streamflood and sheetflood breccias and sandstones with interbedded aeolian sandstones that pass basinward into into massive dune sandstones. Depositional facies are those of very arid intermontane basins summarised in Figure 2 (Brookfield, 1980; Nielsen, 1982). The fan deposits have anguular, poorly sorted clasts and often contain abundant well-rounded, reworked, coarse aeolian sand and reworked ventifacts derived from the fan surfaces. Silt and clay are rare and probably were mostly removed by the wind; nevertheless rare silt and clay beds are occasionally interbedded with the pediment, alluvial fan, and aeolian deposits.
These fine-grained sediments were deposits in ephemeral ponds and lakes and provide additional data on palaeoenvironments. Such deposits are rarely described from sections of ancient and desert deposits because the most impressive units are the alluvial and eolian deposits (cf. Brookfield, 1984).
The purpose of this paper is to record the facies and paleoenvironments of the rare lake and pond deposits of an ancient arid intermontane desert, compare them with modern examples, and note their significance for paleoenvironmental interpretation. Detailed descriptions of the associated facies and justification of the assigned processes and environments are in Brookfield (1978, 1979, 1980, 1989).
Section - Alluvial Fan and Pediment Ponds
After floods, silts and clays can be seen settling out of suspension in small ponds on pediments and alluvial fans. Due to the slope of pediments and the slope and porosity of fans in very arid environments, such pond deposits are exceedingly small, short-lived and likely to be removed during later flash floods; nevertheless such pond deposits can occasionally be preserved beneath overlyin deposits.
In the Thornhill basin, thin pond deposits occur between basalt eruptions on the incised pediments. Figure 3A shows fine-grained sediments deposited in a depression between two successive lava flows. the seidments consist of of two fining-upward cycles, each of which starts with an erosion surface on which rests cross-bedded, graded pebbly sandstone. This is overlain by alternating thin beds of graded sandstones passing up into planar laminated micaceous siltstones overlain by mud-cracked silty mudstone. Each fining-upward sandstone-siltstone bed is between 20 and 50cm thick and probably marks the waning stages of successive sheetfloods across the pediment due to overflows from incised pediment channels. Successive mudcracked surfaces within the overlying mudstone unit indicates sporadic rainfall and redistribution of fine sediment before the next major flood. The end of this particular pond is marked by a thin eolian lag, covered by the next basalt eruption.
.... continues
Cowan, G. 1993. Identification and significance of aeolian deposits within the dominantly fluvial Sherwood Sandstone Group of the East Irish Sea Basin, UK. By Greig Cowan. British Gas Exploration and Production, Reading. In North, C.P and Prosser, D.J. (Editors). Characterisation of Fuvial and Aeolian Reservoirs, Geological Society of London, Special Publication. vol. 73, pp. 231-245.
Abstract:
The Triassic Sherwood Sandstone Group sediments of the East Irish Sea Basin are over 4000 ft thick and comprise medium- to coarse-grained sandstones and rare thin mudstones. Facies models developed during production drilling on the South Morecambe Field show that deposition occurred in a braided fluvial setting with minor aeolian episodes. The major facies associations present are: (A) major channel fill; (B) ephemeral channel fill; (C) non-channelized sheetflood deposits; (D) and (E) non-reservoir fines (abandonment and playa respectively); (F) aeolian dune and sand-sheet. Volumetrically, the major channel (A) and sheetflood (C) facies dominate, and the alternation of these facies associations is correlatable across the field. The aeolian sandstones form units varying in thickness from a few grain diameters up to 3 m thick. The sand-sheet and dune deposits can be correlated over considerable distances and show pressure communication on RFT logs. Although the aeolian sandstones comprise only 5–10% of the reservoir they have very high porosities and permeabilities (up to 30% and 10 darcies) and make disproportionate contributions to flow into the wellbore. The depositional criteria used to differentiate between aeolian and fluvial deposition in the South Morecambe Field are pinstripe lamination, good sorting and lack of rounded clay clasts, but these criteria are not definitive. As a result of the dissolution of an early diagenetic cement, aeolian sandstones have very high porosities compared to fluvial sandstones. This high porosity is reflected in high sonic transit times and allows aeolian sandstones to be identified tentatively in uncored wells by use of sonic logs.
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Durrance, E.M. and Laming, D.J.C. (Editors) 1982 (reprinted 1985, paperback, and 1993). The Geology of Devon
. University of Exeter Press. 346 pp. ISBN 0 85989 247 6. This is a key publication on the area.
"Preface: Geological Field Work: It has often been remarked that geology is a subject best studied by actually looking at rocks, minerals and fossils, and their structures and relationships, in the field. Therefore, although this book mainly deals with descriptions from an interpretative viewpoint, at the end of each appropriate chapter a number of localities are listed which will serve to illustrate the main points dealt with in the text. The localities are mainly arranged in subject groupings, although some geographical subdivision is also present. Excursions to specific areas of Devon, to include visits to a number of sites of different character, may thus
be constructed with the aid of the appropriate Geological Survey maps, according to individual requirements. Excursion Guides to different parts of Devon are also published by the Geologists' Association:
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Gosling, G. 1993. Dawlish and Teignmouth, from Old Photographs. By Gerald Gosling, Amberley Publishing, 160pp. Paperback, Price £14,99p.
"This photographic portrait of a period at once familiar and remote illustrates the heyday of the English Riviera - when one of the countries most scenic railways brought visitors by the thousands for sun, sea and sand - in two of its most popular towns. United by the sea and having some of Devon's finest countryside as their common backdrop, each town retains the distinctive character aquired when these pictures were taken: Dawlish quieter and proud possessor of a stately air that not even Torquay or Sidmouth can match; Teignmouth a bustling port..."
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Great Cliff. 2006. A Brief History of the Railway at Dawlish.
(Part of the website of:
Luxury Self Catering Accommodation in Dawlish Devon - Welcome to Great Cliff a Great Place for that South Devon Holiday.)
Example extracts:
1962. New generation of diesel hydraulic locomotives gradually replace steam locomotives.
Ballast washed out at Marine Parade on 8th March due to storm - Dawlish down platform also damaged.
1971. Major works commence by the Water Authority to help stabilise Dawlish Warren.
1974. Large section of Dawlish down platform demolished by a storm on 11th February.
Work completed on stabilising Dawlish Warren area
[continues with similar type of information]
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Harper, C.G. 1907. [now available reprinted]. The South Devon Coast. This book was mentioned by the Devon Historical Society in relation to Lea Mount, Dawlish. See:
1885: Dawlish Death Trap. by R.G. 2011. This writer draws attention to the following paragraph:
"Lea Mount owes its formal, straight-cut outline to the anxieties tha followed the falling of a portion of the cliff on August 29th, 1885, when over 50 tons of rock buried a party of seven women and children, killing three of them. To prevent further accidents, all overhanging portions were cut away."
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Hawkes
, J. The West Country from the Air. Ebury Press, 128 pp. See pp. 36-39 for superb oblique aerial photographs of Dawlish and Teignmouth. By Jason Hawkes. This book also has excellent, large, colour aerial photographs of other parts of Dorset, Devon and Cornwall, and is highly recommended for purchase. The pictures are probably the best oblique aerial photographs available for the region.
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Hobson, B. 1906. The origin and mode of formation of the Permian breccias of the south Devon coast.
Geological Magazine,vol.3, pp. 310-320. By Bernard Hobson, Lecturer in Geology at Victoria University of Manchester.
Abstract:
After visiting in 1905 the excellent exposure of the Permo-Carboniferous Dwyka Conglomerate, containing glacially striated boulders, overlying glacially striated Barberton beds at the foot of Gotshe Mountain in the Vryheid district of Natal, it occurred to me to examine the Permian breccias of the South Devon coast to see whether I could find any evidence of their being of glacial origin. [very improbable in modern geological terms - IMW]
Example text:
"Along the Great Western Bailway between Teignmouth and Dawlish, North of Teignmouth, at the 208 mile-post (from London) on the railway, the breccia has an apparent dip of 16 degrees to 20 degrees northward, and consists of distinctly angular fragments, mostly about 3 inches [7.6cm] or less, but running up to 7 inches [17.8cm], and exceptionally, in the case of a quartz-porphyry block, 18 inches [46cm] in diameter. The fragments consist of grey quartzite, greenish quartz porphyry weathering reddish, the typical red quartz-porphyry, purplish-red sandstone, black quartzite. No limestone was observed, though, as remarked in reference to Teignmouth, a minute search might discover some. Where large boulders occur in these South Devon breccias they, so far as observed, lie with their longer axes parallel to the bedding planes. For instance, at a point 150 paces south of the 208 mile post (of the Great Western Railway) a quartz-porphyry boulder 2 ft. 8 in. [0.81m] by 9 in. [23cm] by 1 ft. 4 in. [40.6 cm] and partially embedded, elliptical in form, moderately well rounded, lies in the breccia 20ft [6m.] to 30 ft. [9m.] above the rails; 5 paces north of it is a subangular block of fine-grained mottled red sandstone 2 ft. 4 in. [0.71m] by 1 ft. 6 in. [0.46m.] and partially embedded, and about .... Very likely a minute search might discover some."
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Hurst, A., Cartwright, J. and Duranti, D. 2003. Fluidization structures produced by upward injection of sand through a sealing lithology. p. 123 et seq. in Van Rensbergen, P., Hillis, R.R., Maltman, A.J. and Morley, C.K. (eds), 2003. Subsurface Sediment Mobilization. Geological Society, London, Special Publications, 216, 123-137.
Abstract [part]: Subsurface and outcrop data are used to describe sand injectites, a group of genetically related features that include sandstone dykes and sills, but also structures within depositional sand bodies. Fluidization is a process by which sand is injected but we draw attention to the lack of constraints regarding fluidization velocity and fluid viscosity. Injectites are shown to develop between less than 10m and 500m below the seafloor. No relationship between depth of generation and injectite geometry is found. Liquefaction of sand may produce sufficient excess pore fluid to create small sand injections during shallow burial. Large injectite bodies ..... Many of the processes of sand injection remain poorly constrained. [end of abstract]
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Kay
, P. 1990 (Second Impression 1991). Rails along the Sea Wall. Platform 5 Publishing Ltd., Lydgate Lane, Sheffield. 60pp. By Peter Kay. [This discusses the history of Brunel's railway line along the coast of south Devon, including the stretch between Dawlish sea front and Dawlish Warren. This paperback book (was only 6 pounds) contains much useful historic information and contains numerous superb old photographs of the railway line, the sea wall and coast in general. [I purchased it some years ago at the Red Rock Cafe at Langstone Rock.]
Abstract:
Detailed recording of small-scale changes for more than a decade has made it possible to suggest reasons for the accelerating erosion of this sand spit across the mouth of the River Exe. It is suggested that the processes operating in this site are characteristic of those at similar sand spits in a late stage of development. Attempts to halt or slow down erosion are reviewed and possible developments in the future are touched upon.
[Example text - Introduction]
"In common with most other coastal sand and shingle structures, Dawlish Warren has a history of continual change. For roughly the last hundred years the cumulative effects of these changes have, from time to time, led to fears for the stability of this composite sand spit at the mouth of the River Exe in Devon. This is not surprising since much depends on it. It is an important element in the natural sea defences of the main railway line, which runs along the western shore of the estuary, of the harbour at Exmouth and of the entrance to the Exeter canal at Turf. It does much to reduce wave action in the estuary and so is important in the functioning of navigation, including that of the Exmouth to Starcross ferry. Quite apart from this coast defence aspect, Dawlish Warren has great amenity value in itself. Many thousands of holiday-makers throng its beaches in the summer and golfers use it throughout the year.
The ultimate doom of the Warren and its replacement by 'a dangerous bay of shoals' was forecast almost one hundred years ago (Peacock, 1869). Three papers by J. M. Martin (1872, 1876, 1893) discuss the changes in Dawlish Warren up to the end of the last century and put forward a number of ideas to account for the continuing erosion. R. Hansford Worth (1907) felt that fears for the safety of the Warren had been 'somewhat exaggerated' and suggested that the changes taking place indicated 'rearrangement rather than destruction'. The present writer (Kidson, 1950) forecast a life of ten to fifteen years for the Outer Warren, in the absence of major defence works, and suggested that the next paper on the subject might well describe the realisation of Peacock's oreboding.
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Kingdom, A.R. 2008. The Sea Wall Between Teignmouth and Dawlish. 32pp. Ark Publications (Railways). With many monochrome photographs. With photographs mostly postcards of Chapman and Son, Dawlish.
Extract from the Introduction:
(The first section, on p.5, is about Teignmouth and Dawlish in 1941 and during the Second World War.)
(continues on p. 6.)
Now, some 66 years later, the threat of war and consequent attack is a dimming recollection in the minds of my generation. Nevertheless the threat of invasion is very much with us, the only difference being that it is from the sea itself, which continues, relentlessly, to erode the soft sandstone cliffs and shore. It is in fact for this very reason that throughout the 160-plus years of its existence the sea wall has seldom been out of the news, especially in recent times with the onset of global warming and rising sea levels.
At this point, it is perhaps, interesting to reflect that in the late 1930s no less than three alternative inland deviations for the railway line were proposed and that even an Act of Parliament was passed. However, escalating costs and the onset of the Second World War put paid to this venture and the status quo remains to this day. This, in turn, means that if the sea wall did succumb to the elements and the line had to be closed the effect on the local economy of places such as the seaside towns of Teignmouth and Dawlish, not to mention that of the South West as a whole, would be catastropic. It only remains for me to say, therefore, that whatever the cost of keeping it open, this vital West Country link and the truly scenic gem into which it is set must be preserved for the well-being and enjoyment of both the present and future generations alike. A.K. Kingdom, March 2008.
.
Dr. Deryck J.C. Laming, of Exeter, well-known author of many publications on Devon geology. See for example: Durrance, E.M. and Laming, D.J.C. (Editors) 1982, The Geology of Devon. University of Exeter Press, 346 pp. (see Chapter 1 - Introduction; and Chapter 7, The New Red Sandstone, pp. 150 et seq. etc.)
Laming
, D. J. C. 1954. Sedimentary Processes in the Formation of the New Red Sandstone of south Devonshire. PhD Thesis, University of London.
Laming, D. J. C. 1958. Fossil winds. In Polar wandering and continental drift - a symposium, Journal of the Alberta Society of Petroleum Geologists, 6, Calgary, 179-183.
Laming, D. J. C. 1965. Age of the New Red Sandstone in south Devonshire. Nature, London 7th August 1965, 207, pp. 624-625. Letters to Nature. [Dr. Laming was at about this time at the University of Reading and University of New Brunswick.]
Radiometric dating of the Exeter Volcanic Series (the Exeter Traps) recently gave ages of 279 ± 6 m.y. and 281 ± 11 m.y. for the Killerton mica-lamprophyre (minette) and the Dunchideock basalt respectively. These and other extruded masses of the Series are interbedded with breccias and sandstones of the New Red Sandstone both north and south of Exeter, and as far west as Hatherleigh; new evidence is thus provided of the age of the strata. The main intrusive event of the Dartmoor granite is dated at 295 m.y., the paroxysmal phase of the Variscan Orogeny being regarded as preceding this by only a short time. Smith puts the Permo-Carboniferous boundary at 280 m.y. [20 references follow]
Laming, D. J. C. 1966. Imbrications, palaeocurrents and other sedimentary features in the Lower New Red Sandstone, Devonshire, England. Journal of Sedimentary Petrology,[Journal of Sedimentary Research] 36, 940-959. By Dr. Deryck J.C. Laming.
Abstract:
Unmetamorphosed red clastic late Carboniferous to Triassic rocks exposed along the south Devon coast consist largely of sedimentary breccias in the lower part of the succession and of sandstones and siltstones in the upper part. Coarse beds are interpreted as alluvial fan deposits formed under semiarid conditions. Imbrication of phenoclasts in the breccias has been analyzed, and is defined and related to the mode of deposition. Sheetflood fluvial and channel fluvial paleocurrents are deduced from the direction of the imbrication. Directions of eolian transport are also determined. Rain prints, desiccation cracks, and large annelid burrows are present in a few localities.
Laming, D. and Roche, D. (undated but recent). Permian Breccias, Sandstones and Volcanics. Devon Geology Guide. Devon County Council.
Devon Geology Guide..
Go to: Permian Breccias, Sandstones and Volcanics, 466kb pdf, available by clicking on a link provided.
Example text, at the beginning:
"Breccias and sandstones are types of rocks which are found in Devon dating from a geological time named the Permian period. Both these types of rocks are generally known as sedimentary rocks. Sedimentary rocks form when material or sediment is deposited and compacted to form a rock. Beccias get there name from the definition of the word ‘breccia’, which means rubble. The rock of this type found in Devon is formed
of angular gravels. Sandstone is a rock which is formed of sand grains which are compacted and cemented together. Both the breccias and sandstones seen in Devon were formed in tropical desert conditions between about 250 and 300 million years ago. The Permian red rocks were deposited as gravels and sands, formed by erosion of high mountains to the west, which had been created by earth movements following the
continental collision in the preceding Carboniferous geological time period. Deep canyons led eastward from the mountain flanks down to a large desert plain over east Devon and beyond. Occasional storms in the uplands sent flash floods down the canyons, carrying large amounts of loose rock, sand and mud, and large fans of gravelly sediment were laid down. Sand grains were picked up by the wind from these deposits and were blown into sand dunes..." [continues]
.
Leeder, M. 1999. Sedimentology and Sedimentary Basins: from Turbulence to Tectonics.
Blackwell Science Ltd., 592 pp. ISBN-13:978-0-632-04976-9, paperback. For information on sediments of the type occurring in the Permo-Trias of Devon, see Alluvial Fans and Fan Deltas, p. 330-339; and Aeolian Sediments in Low-latitude Deserts, pp. 295-306.
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Marsden, C.J. 2009. Dawlish Sea Wall: The Railway between Exeter and Newton Abbott. Ian Allan Publishing. 96pp. Large paperback. By Colin J. Marsden, first published 2009. This is the best publication that I am aware of, with numerous photographs, modern and historic, of the Dawlish and Teignmouth sea walls and railway lines. About half the photographs are in colour with the others in monochrome. Some colour photographs are very large and cover two pages. This books contains valuable historic information in the form of old photographs. Original price £14.99.
(See also the smaller book on a related topic: Kay, 1991)
Example extract p.3:
"Introduction: Firstly welcome to: Dawlish Sea Wall: The Railway between Exeter and Newton Abbott. Over the years much has been written about the 21 miles of railway line between Exeter and Aller, west of Newton Abbot which is affectionately known as the Dawlish Sea Wall line. There is probably no other section of railway line in the world which attracts the interest that the Dawlish Sea Wall generates. Locations such as Dawlish, Langstone Rock and Cockwood Harbour are without doubt the most photographed locations anywhere, with only on some occasions, when special or unusual locomotives have passed by, upward of 200 photographers being recorded. There are likely to be many reasons why the route has attracted such interest - its splendid scenery, ease of access and wide variety of train types the most common reasons, but the not infrequent inclement weather with waves crashing over the line inflicting structural damage to the fabric of the line also attracts interest, especially if people can stand and watch the storm seas crashing over the line and into the streets.". ... continues
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Martin, 1872. Exmouth Haven and its threatened destruction.
Report and Transactions of the Devon Association for the Advancement of Science, Literature and Art, vol. 5, 1872, pp. 84-89.
Martin, 1876. The changes at Exmouth Haven. Report and Transactions of the Devon Association for the Advancement of Science, Literature and Art, 8, 1876, 453–460.
Martin, J.M. 1893. The changes at Exmouth Haven. Report and Transactions of the Devon
Association for the Advancement of Science, Literature and Art, 25, 406–415.
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Mockett, I.D. and Simm, J. 2002. Risk Levels in Coastal and River Engineering. 272 pp. By Ian Mockett and Jonathon Simm. Hardcover, 29th November 2002. This book is available from Amazon and other suppliers. The Amazon price is £78.26p. Only part, Case Study 3, is concerned with the railway and seawall at Dawlish. It does appear to make clear who is responsible for just what risks, but it has not been studied in full by the writer. Parts only are available on online as example content.
See p. 183 et seq.
Case Study 3, Dawlish Seawall.
Example extract, p. 183:
"The current structure is a concave seawall with a low return wall and toe protection. The materials used to construct the wall are limestone blocks that have a minimum thickness of 650mm., with the infill material behind the wall to support the tracks consisting of a permeable mixture of rock and shingle. The seawall itself is founded on soft breccia sandstone. A small beach provides some protection to the toe of the structure...
Construction of the existing Dawlish seawall commenced in 1845 under the direction of Brunel as part of the South Devon Railway. The management and maintenance of the seawall at Dawlish has been an engineering challenge right through its lifetime. Even during the construction phase, considerable problems were experienced in 1846 with a breach in the wall. Various remedial and reconstruction works were carried out over the early years to mitigate against a number of problems including sections of the wall collapsing and the railway track being washed away. Most of the wall comprised the original construction, although a few sections have been completely rebuilt at one time or another."
Example extract, p. 187.
"The Present Situation.
Where there are significant voids in the track support structure, attempts are made to fill these voids. The toe detail which cannot be constructed in one phase, is prioritised on the basis of where it is most needed. Some localised parts of the frontage have also undergone refacing of the existing seawall. No work on the beach has been undertaken at this time, nor any attempt to reduce overtopping of the seawall. "
Example extract, p. 191.
"After a probilistic analysis of waves and water levels, it is concluded that green water overtopping within the next 50 years is very unlikely, and so it was decided that a new coping for the sea-wall is not necessary. Wave-induced overtopping happens frequently, but Railtrack felt that the inconvience was tolerable compared to a risk of a catastrophic failure of the track support.
"It is concluded that raising groynes by 500 mm. would have a beneficial impact on the shape of the beach, but there is fear that the forces on the groynes will be such that they will not last as long as the existing groynes...."
See also discussion on p. 186 on: Reduction in beach levels, undermining of the toe, voids behind the sea wall, and overtopping.
See also, p. 201:
"The risk that Railtrack is trying to minimise is the delay of trains because Railtrack is liable to pay a penalty for every minute a train is delayed due to a track closure of a speed restriction. Any properties, assets and lives protected by the seawall are of no (economic) interest to Railtrack."
.
Mottershead , D.N. 1986. Classic Landforms of the South Devon Coast. Classic Landform
Guides, No. 5, Geographical Association, Sheffield, 48 pp.
.
Morris, S. 2007. Millionaire left with even better sea view after cliff landslide. The Guardian Newspaper, Tuesday, 6th February 2007. By Steven Morris. [Short article with a photograph].
A luxurious clifftop home being built for a wealthy businessman now boasts an even better view after a large chunk of land crumbled into the sea. The landslide, in which 25m (82ft) of land and several large pine trees vanished, left the house, which has:a glass spiral staircase and indoor pool, perched close to the clifftop. The landslide was witnessed by carpenter Daniel Julyan and his father, Philip, as they put the finishing touches to the house in Dawlish, south Devon. Daniel, 19, said: "Quite often we'll hear a rumbling when a train goes by on the local railway line. But this just kept going and got four or five times louder. It was like thunder.
We looked over the edge and there was a mile of red dirt and branches and stuff floating inthe ocean. I suppose the only good thing is it's opened up an even better view." Daniel said the garden fell away close to where he and his father usually sit and eat their lunchtime sandwiches. He said: "It's quite scary to think we usually eat about 15 metres away from the bit that fell. We'll be eating lunch somewhere else from now on." The house is being built in the garden of millionaire Nick Skilton and is due to be finished in the summer. However, the L-shaped chunk of land that slipped away was owned by a property developer, Character Homes, which is building a block of luxury apartments nearby. Though the landslide brings both Mr Skilton's home and the new house closer to the clifftop he insisted he was not concerned: "I am not a bit worried about my home." Michael Hogg, owner of Character Homes, said: "There is just a sheer drop there now. I went to see it and I am trying to find reasons why this happened. "We really have no reason to be concerned. We have just lost a few trees and snowdrops. But it has put the new house very close to the cliff face indeed."
.
Newell, A. J. 2001. Bounding surfaces in a mixed aeolian-fluvial system.[key paper on the Dawlish Sandstone]
Marine and Petroleum Geology, vol. 18, no. 3, pp. 339-347. By Andrew Newell of the British Geological Survey. [available online]
The Dawlish Sandstone Formation is a Late Permian succession of mixed aeolian and fluvial deposits in the Wessex Basin (SW England). It is used to illustrate two contrasting types of fluvial/aeolian bounding surface (planar and incised). Planar bounding surfaces separate tabular bodies of fluvial conglomerate and aeolian dune sandstone. They were produced primarily by wind scour to groundwater table, with the later emplacement of conglomerates resulting in local fluvial erosion of cemented aeolian dune sandstones. Incised bounding surfaces were produced by fluvial downcutting. The erosive relief was infilled with mixed aeolian/fluvial deposits. The Dawlish Sandstone Formation may provide the first outcrop example of these incised valley fills, which have recently been identified as a major component of the subsurface Rotliegend in the Southern North Sea Basin. The potential variability of aeolian/fluvial sedimentary architecture has important implications for well-to-well correlation and reservoir modelling.
[see the full paper, available online]
It commences as follows: "Interbedded fluvial and aeolian deposits form a major part of continental clastic reservoirs such as the Rotliegend Group of the southern North Sea Basin (George and Berry, 1993; Howell and Mountenay, 1997) and the Sherwood Sandstone Group in the East Irish Sea (Cowan, 1993; Meadows and Beach, 1993). It is now well documented that clean, well-sorted aeolian sandstones generally have significantly higher reservoir quality than fluvial deposits (Cowan, 1993; Ellis, 1993; Hern and Steel, 1997). To understand the fluid flow properties of a reservoir, it is thus imperitive to determine the geometry and relationship of fluvial and aeolian deposits......
The aim of this paper is to use the well-exposed Dawlish Sandstone Formation (Permian, SW England) [late Permian - Tartarian] to provide insight into two types of aeolian/fluvial bounding surface (1) planar, and (2) incised. The contrasting sedimentary architecture associated with each type of bounding surface has important implications for well-to-well correlation and reservoir modelling. The outcrop sections [at Dawlish] are particularly relevant as analogues for reservoirs deposited in erg-margin settings, such as those found in the Rotliegend of the Southern North Sea Basin." .. continues.
Fig. 8 of this paper, on p. 345, neatly summarises the differences diagrammatically between plan and incised bounding surfaces. Notice that in the case of incision a fluvially reworked aeolian sediment may be present [and this you might not necessarily expect].
.
Nichols
, G.J. and Fisher, J.A. 2006. Processes, facies and architecture of fluvial distributary system deposits.
Sedimentary Geology. The full version is available online a corrected proof from Science Direct.
Abstract: There is evidence from the stratigraphic record of examples of fluvial deposits that were the products of deposition from river systems which had decreasing discharge down-flow and transitions from proximal, channelised to distal, unconfined flow. These deposits form fan-shaped bodies several tens of kilometres in radius, and their stratigraphic architecture is aggradational, with no evidence of deep incision driven by base-level fall. The fluvial systems that generated these deposits formed under conditions for which there is no complete analogue today: an endorheic basin with a relatively arid climate adjacent to an uplifted area with higher precipitation. A conceptual model for fluvial systems of this type has therefore been built on the basis of outcrop examples and a consideration of the controls on sedimentation. Proximal areas are characterised by amalgamated coarse, pebbly and sandy channel deposits with little preservation of overbank facies. Channel dimensions are generally smaller in the medial areas, but sizes are variable: deposits are of braided, meandering and simple channels which show varying degrees of lateral migration. The channel-fills may be mud or sand, with overbank flow processes playing an important role in filling channels abandoned on the floodplain after avulsion. The proportion of overbank deposits increases distally with sheets of sand deposited as lateral and terminal splays by unconfined flow. Interconnection of sandstone bodies is poor in the distal areas because channel-fill bodies are sparse, small and are not deeply incised. The radial pattern of the sediment body forms by the repeated avulsion of channels: active channels build up lobes on the alluvial plain and rivers switch position to follow courses on lower lying areas. The term ‘fluvial distributary system’ is here used to describe a river system which has a downstream decrease in discharge and has a distal zone which is characterised either by terminal splays on to a dry alluvial plain or a lake delta during periods of lake highstand.
.
Perkins
, J.W. 1971. Geology Explained in South and East Devon. David and Charles, Newton Abbot, 192pp. By John W. Perkins. Clearly written with very good, well-labelled, sketch illustrations by the author.
Extract from the Introduction:
"The basic ingredients of the county's rolling landscape are the high moorland centre, the surrounding low lands bevelled to various heights and deeply trenched by rivers, and the sinuous coastline with its penetrating estuaries and grand cliffs. Written for all who love South Devon, either as a tourist area or a place to live in, this book aims to deepen their understanding and enjoyment. It may also help to popularise geology in a wider sense, and should remind us that we are tenants of a heritage millions of years old, and one that we must do our best to conserve. It has been assumed throughout that the reader will constantly have a compass, a one-inch geological map and a one inch ---- map at hand."
.
Robinson
, A. and Millward, R. 1983. The Shell Book of the British Coast. David and Charles, Newton Abbot, 560pp.
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Rossiter, K. 2014. [Keith Rossiter] Rail link hit again at rogue wave halts train at Dawlish. Western Morning News, 10th October 2014.
Go to Western Morning New article, with good photograph:
http://www.westernmorningnews.co.uk/Rail-link-hit-rogue-wave-halts-train-Dawlish/story-23079585-detail/story.html
See the full article with a picture: there follows a shortened extract.
"The main railway line at Dawlish is still vulnerable to storms, in spite of £35 million of repairs.... A Cross Country train was halted on Monday after it was hit by a wave at Dawlish.... Network Rail admits that it cannot do anything to prevent similar incidents. On Monday [6th Oct. 2014] the 6.34am train from Bristol towards Plymouth was swamped by a wave at Dawlish. Cross Country said its relatively new Voyager trains were vulnerable to seawater because air intakes in the roof allow water to get into the electrics. .... the driver continued on to Newton Abbot where he rebooted the train’s computerised system. But a few miles further, outside Dainton, the train stopped again, and was unable to get going again for 30 to 35 minutes. .... this was a problem peculiar to Cross Country’s Voyager trains. The company ... does not operate along that stretch of line when high waves are predicted. But ... there was no forecast of high waves. .. A Network Rail spokeswoman said: "Our control room can confirm that the train was struck by a wave on Monday at Dawlish. This happens from time to time ... given the location of the railway line and its proximity to the sea wall. Normally it isn't a problem and trains can carry on as normal, as other than Cross Country, other train services are equipped to deal with salt water. However Cross Country trains aren’t. .... Network Rail was doing "resilience" work in the Dawlish area, but .. "This isn’t really a resilience issue. Our work is to prevent what happened at the beginning of the year happening again, however we cannot help the fact that waves will hit trains – this will always happen due to the proximity of the line to the sea wall." ..
Councillor Andrew Leadbetter, chairman of the Peninsula Rail Task Force, said: "This is not entirely unexpected, and we are likely to see similar incidents in the future. .. as an absolute minimum the Dawlish line must be reinforced to withstand winter weather. The Peninsula Rail Task Force partnership is holding the Government to its pledge to ensure the line is resilient, as well as looking at additional routes. Any additional route will take time to implement, so regardless of future plans, ensuring safe and regular access in and out of the South West is vital, and that means ensuring Dawlish is able to withstand severe weather. .. After last winter’s storms more than 300 engineers, working round the clock, repaired the main 100-metre breach with almost 5,000 tonnes of concrete and 150 tonnes of steel. ... work will continue into next year to complete the repairs, including work to stabilise parts of the cliff between Teignmouth and Dawlish by removing slipped material, and adding netting and nailing to prevent any movement towards the track. Last month Network Rail’s engineers started improvement work on the final section of seafront walkway between Rockstone and Coast Guard footbridges at Dawlish. The work includes building a new protective wall and raising the walkway so that it can be used in all tidal conditions. ..."
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SCOPAC. Hope's Nose, Torquay to Holcombe. SCOPAC report online.
Go to:
Hope's Nose, Torquay to Holcombe.
Geomorphology and Evolution:
Much of this coastline is characterised by unprotected cliffs formed within distinctive reddish sandstones and breccias that back a sequence of small bays, or coves, and intervening headlands e.g. Photo 1. However, the estuary of the River Teign and a complex pattern of nearshore and offshore banks beyond its mouth introduce discontinuity (Photo 2). With the exception of the Teignmouth frontage (Photo 3), beaches are narrow and composed dominantly of sand with some fine gravels. Longshore drift south of the Teign estuary mouth, and also between Spey Point and Holcombe, is from south to north but is both weak and compartmentalised. Between northern Teignmouth and the distal end of Denn spit the net drift pathway is from north to south, creating a convergence of littoral transport at the mouth of the Teign. Thus, there are three distinct partly independent, sub-cells of beach and nearshore sediment movement as follows: [...continues]
.
Ussher, W.A.E. 1913. The Geology of the Country around Newton Abbot
. By W.A.E. Ussher, F.G.S., with contributions by Clement Reid, F.R.S.; J.S. Flett, M.A., D.Sc.; and D.A. MacAlister, A.R.S.M.
Memoirs of the Geological Survey of England and Wales, Explanation of Sheet 339, Newton Abbot. Published by order of the Lords Commissioner of His Majesty's Treasury, H.M. Stationery Office. 149pp. with two plates of photomicrographs and with an Appendix - List of Principal Works on the Geology of the District. [a copy of this memoir is in the NOC Southampton Library].
Extract from Preface:
"This memoir is an explanation [the old explanation] of Sheet 339 of the New Series Geological Map [actually old and now superseded by a modern BGS map] on the scale of one-inch to one mile. The original geological survey of the area, by Sir H.T. de la Beche, was to a large extent founded on earlier work by Godwin-Austen. It is was published in 1884 on Sheet 22 of the Old Series. A revision of the area on this old series one-inch map was carried on at intervals between 1874 and 1887 by Messrs. Woodward, Ussher and Reid. This, supplemented by some later revision on the six inch scale by Mr. Ussher, was transferred to the New Series map and published in a hand-coloured edition in 1899. In preparing the present colour-printed edition advantage has been taken of the opportunity to include some still later observations recorded by Mr Ussher on the six-inch map. Mineral lodes have been laid down, from old mine-plans, by Mr. MacAlister......" [continues].
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© 2014 Ian West, Catherine West, Tonya Loades and Joanna Bentley. All rights reserved. This is a purely academic website and images and text may not be copied for publication or for use on other webpages or for any commercial activity. A reasonable number of images and some text may be used for non-commercial academic purposes, including field trip handouts, lectures, student projects, dissertations etc, providing source is acknowledged.
Disclaimer:
Geological fieldwork involves some level of risk, which can be reduced by knowledge, experience and appropriate safety precautions. Persons undertaking field work should assess the risk, as far as possible, in accordance with weather, conditions on the day and the type of persons involved. In providing field guides on the Internet no person is advised here to undertake geological field work in any way that might involve them in unreasonable risk from cliffs, ledges, rocks, sea or other causes. Not all places need be visited and the descriptions and photographs here can be used as an alternative to visiting. Individuals and leaders should take appropriate safety precautions, and in bad conditions be prepared to cancell part or all of the field trip if necessary. Permission should be sought for entry into private land and no damage should take place. Attention should be paid to weather warnings, local warnings and danger signs. No liability for death, injury, damage to, or loss of property in connection with a field trip is accepted by providing these websites of geological information. Discussion of geological and geomorphological features, coast erosion, coastal retreat, storm surges etc are given here for academic and educational purposes only. They are not intended for assessment of risk to property or to life. No liability is accepted if this website is used beyond its academic purposes in attempting to determine measures of risk to life or property.
Webpage - written and produced by:
Ian West, M.Sc. Ph.D. F.G.S.
.
at his private address, Romsey, Hampshire, kindly supported by Southampton University,and web-hosted by courtesy of iSolutions of Southampton University. The website does not necessarily represent the views of Southampton University. The website is written privately from home in Romsey, unfunded and with no staff other than the author, but generously and freely published by Southampton University. Field trips shown in photographs do not necessarily have any connection with Southampton University and may have been private or have been run by various organisations.
