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Aerial photographs by courtesy of The Channel Coastal Observatory , National Oceanography Centre, Southampton.
|St. Aldhelm's Head
|Winspit and Seacombe
|Anvil Point to Blackers Hole
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|Durlston Head |
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St. Aldhelm's Head to Durlston Head, Isle of Purbeck - Other Webpages
St. St. Aldhelm's Head...
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Hd - Anvil Point to Blackers Hole
St. Aldhelm's Hd to Anvil Point - Bibliography
More Related Field Guides and Bibliographies ---
| Durlston Bay -Lower Purbeck | Durlston Bay Bibliography |
Purbeck Formation Bibliography | Purbeck Palaeoenvironments |
| Durlston Head, Isle of Purbeck
|St. Aldhelm's Hd to Anvil Point - Geological Bibliography
|Durlston Bay - Peveril Point, Upper Purbeck Formation
|Durlston Bay, Middle Purbeck
Durlston Bay - Lower Purbeck
|Durlston Bay - Central Zigzag Part & Coast Erosion
|Durlston Head - Lower Purbeck Formation & Portland Stone
|Durlston Bay - Bibliography
|Portland - General
|Portland Bill
General
Dancing Ledge is a large gently sloping ledge of part of the Portland Cherty Series, accessible from a large abandoned quarry above. It is said to have received its name from the appearance waves "dancing" on the ledge or because the sea ledge was humourously suggested to be as big and flat as a dance floor (
Bruce, 1989). Although there is no evidence for this, it is also possible that the name is some corruption of a reference to the springs which occur on the hill above and lead to water trickling over the cliff at Green Point - eg. "dark spring ledge"? The upper, quarried ledge has some adits, now partly closed, and some old piles of quarry debris with some fossils. The area is used for the training of rock climbers. A bathing pool
has been quarried out of the lower ledge for Durnford Preparatory School.
The quarry, cliffs and ledge here provide a good section through the upper part of the Portland Cherty Series and through the Portland Freestone. Fallen blocks of stromatolitic limestone come from the basal Purbeck Formation above. Ammonites can be seen, various features of silicification are clear, sponge spicules can be seen in the chert, bivalves in the Portland Freestone are common. There is a small karstic cave and interesting travertine features. Cave development by the sea can be studied. To the east of Dancing Ledge is a significant fault affecting the cliffs and the topography just inland. A dry valley with hillwash deposits descends to the quarry, and the topic of former water flow in the area is of interest.
Jointing in the Portland Stone is also interesting and could be studied and assessed by statistical methods as part of a student exercise.
INTRODUCTION:
INTRODUCTION:
Access: Walk to Dancing Ledge
Dancing Ledge (SY 997768) can be reached by Durnford Drove, a lane south from Langton Matravers, parking and walking to Spyway Barn (SY 999777 - National Trust with information), and going down the hill to the cliff.
(An alternative route is a longer, walk along the cliffs, 3 and a half kilometres from Durlston Castle (SY 035772) and Durlston Country Park (SY 032773), south of Swanage.)
To give more detail, first drive to Langton Matravers, which is an old quarrying village to the west of Swanage, Isle of Purbeck, east Dorset, southern England. Here is a location map for Langton Matravers. You can click here for more information and zooming, if needed.
In Langton Matravers find Durnford Drove. This is a road turning off to the south from about the middle of the High Street in the village (you can make a mistake and take the wrong turning - look specifically for the road name sign "Durnford Drove"). Turn down this and drive on for a few hundred metres south to the end of the tarmac road (and a turning circle). Then go onward using the rough stone road for another few hundred metres until you come to a National Trust car park. Park on the grass and walk towards Spyway Barn, a farm up on the hill top. It is almost a straight route to the south.
Beyond Spyway Barn you will find a National Trust footpath and steps down the steep hill side. At the bottom is a stile and a path in to the top of the quarry.
You will now be on the path above the quarry. See where the people are near the fence, with some of them having a picnic.
From the viewpoint go down the steps into the old working floor of the Dancing Ledge Quarry. The wide quarry floor gives excellent views of the strata and of the sea. Most people go just to here, and walk around the old cliff quarry. It is, however, possible to go further down to the sea (see section on Lower Ledge below).
INTRODUCTION:
Topographic and Geological Maps
Recommended for location and topographic information is the Ordnance Survey Outdoor Leisure Sheet 15, 1:25,000 - Purbeck and South Dorset. The Geological Map is the Swanage Sheet - 343 and Part of 342, obtainable from the British Geological Survey .
The British Geological Survey map, 1:50,000, Solid and Drift, 2000 Edition, Swanage Sheet, 343 and part of 342, is well worth purchasing. It can be obtained from the British Geological Survey website and is very inexpensive, costing only 12 pounds sterling. The map shown above is the new edition of the year 2000. It is different in some respects from older editions. Much of the nomenclature is relatively new but if you already know the stratigraphical sequence in the old terminology, it is quite easy to translate to the new language. The new map shows new data offshore and this is not on the old editions; it also shows areas of quarried-out ground. It shows less faults and less dip data for this part of the coast. Thus, both old and new editions should be used for serious study of these cliffs.
AERIAL PHOTOGRAPHS
Seacombe, Dancing Ledge, Blackers Hole and the Amphitheatres etc.
INTRODUCTION:
Stratigraphical Succession
This classic diagram, based on Arkell (1933) shows the general uppermost Jurassic/basal Cretaceous succession in the Isle of Purbeck , compared with that on the Isle of Purbeck. The Purbeck sequence follows. This classic sequence of clays and limestones has been described by Arkell (1933; 1947) and many other authors. Sedimentology has been discussed by Townson (1975), West (1975), Bosence (1987) and others. Note that there are correlation problems and arguments referred to in the section on Zones of the Portland Group, below.
Two alternative schemes for the terminology of the Portland and Purbeck successions are given here. Townson (1975) introduced a largely new terminology. However, it has not been widely used and the traditional scheme of Arkell, shown on the left is still in more common use (diagram after Bosence, 1987, from Townson, 1975). See Wimbledon (1986) for some discussion of this, and note also that some correlation problems which affect this are discussed in the section on zones, below.
Cliff Section - St. Aldhelm's Head to Durlston Head
LOCATION:
Upper Ledge, Old Quarry
Here are some views of the upper ledge which is the abandoned Dancing Ledge Quarry. The left and central views are from the coast path above, walking from the east. The right-hand one shows the lower ledge in the eastern part of Dancing Ledge. Notice in the central image the situation of the quarry at a small valley. The photographs show the two main levels at the quarry, a broad ledge near sea-level composed of a gently southeast dipping unit of the Portland Cherty Series, which will be discussed later, and and upper, intensively quarried ledge of Portland Freestone, seen here. This upper ledge or upper part of Dancing Ledge is almost entirely artificial and is the result of the large volume of quarrying, much of it to create Ramsgate sea and harbour wall ( Bruce, 1989). Some rubble is left but most of the stone has been removed, and there are no large stacks of waste stone as is common on the Isle of Portland.
Apart from the extensive open-cast quarrying there are also some galleries in the Under Freestone near the path down to the ledge.What were formerly quite large openings in this northwestern embayment of the quarry have been partly closed in leaving just the barred openings for bats which you can see as square black apertures. The cliff edge above has received a coating of some some black netting, presumably to reduce danger from falling rocks.
STRATIGRAPHY:
Upper Ledge - Portland Freestone Succession
The succession of Portland Freestone here is similar to that of Seacombe and Worth Quarry. The galleries are in the Under Freestone and Under Picking Cap. The House Cap is shelly and lies above the level of the galleries. The Chert Vein, Bed S, (with the Listy Bed) is easily seen. Above that is the Pond Freestone, not of easy access here and then comes the Titanites Bed which is shelly. The top of the Portland Freestone succession is formed by the white and splintery Shrimp Bed. Thin bedded clays and limestone of the basal Purbeck Formation complete the sequence in the cliffs. These Purbeck strata are most thickly developed at the eastern end of the cliff above the upper ledge. They are not easily accessible here but there are fallen blocks of stromatolitic (thrombolitic) limestone in the quarry debris.
Here is a rather poor impression of a Titanites ammonite, in a block lying loose in the western extension of the upper quarry. It may be from the Titanites Bed. This giant ammonite is of Perisphinctid type and it is surprising that such large cephalopods apparently lived in the relatively shallow waters of the Portland Stone sea. A good place to see better examples of Portland ammonites is at the Portland Heights Hotel, Isle of Portland .
LOCATION:
Upper Ledge - Back Cliffs with Basal Purbecks
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LOCATION:
Upper Ledge - Cave, of Karstic Origin
At the back (north side) of the upper quarried ledge of Dancing Ledge is this small natural cave. It is situated in an interesting place. It is now largely filled with rubble, but at one time was clear to about 1.5 m (in the 1950s). It is vertical and roughly circular in cross-section. Consider the origin of this and look at the signs of traverine around and above it. (The scale is Ian West in September, 1999).
LOCATIONS:
Upper Ledge - Rock Samphire
Shown for general natural history interest is this rock samphire, Crithmum maritimum, above a sea cave at the extreme western end of the Dancing Ledge - upper ledge. It is very common on these cliffs and is shown here in September (1999). It is a greyish hairless perennial with fleshy lobes and yellow flowers.
LOCATION:
Upper Ledge - The Stone Quarrying
The quarrying of the upper ledge, the main part of Dancing Ledge was partly opencast and partly in horizontal mines or galleries. Some of these near the far western end are almost closed now by fallen debris. Those in the northern re-entrant have been artificially blocked in recent years and have a grill for the entry and exit of bats. Years ago all these galleries were open and accessible to humans and I often used to go in them and look at the bivalves in the roof. Presumably bats are exempt from modern health and safety regulations.
The quarrying on the cliffs at Dancing Ledge and other nearby coastal quarries was only possible because back in the 19th century it was economical to transport the stone by sea. Later, when it became much more common to transport stone by road, it was still not feasible to move the heavy stone up the hills of this coast, either using the old system of by horses or later by motorised road transport (Benfield, 1948). Quarrying then only continued at places where there was reasonable road access. Neither Dancing Ledge Quarry or Hedbury Quarry had this.
According to Stanier (1996) Dancing Ledge Quarry was worked in the open by James Webber and two or three men, but activity was at a standstill in 1893. The quarrying of the Portland Stone here in the cliffs was never easy. It seems to have been more difficult in some respects than the quarrying of Purbeck Stone, where relatively thin individual beds have shale or marl between. In addition there was a great overburden of stone that was then regarded as useless. As far as possible this had to be removed but to some extent adits or "caves" were cut into the wall of Portland Freestone. At Dancing Ledge most of these are now inaccessible and some have been closed off with rectangular grills and are preserved for the use of bats.
Very primitive cranes were used in the 19th century for lowering limestone blocks from the main quarry working floor to the lower ledge. The above illustration shows the type of simple crane, operated by a ships-wheel type of winch. These must have been difficult and dangerous to use. In the photograph below a well-known quarry owner of this region, Trev Haysom explains the process.
Trev Haysom, the Marbler, points out how the stone was lowered and shows the relics of a crane-place. Just here we are above the western end of the Lower Ledge. Perhaps this is the site of the crane shown in the 1910 photograph.
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LOCATION:
Lower Ledge and Cherty Series - General
You can, if you consider it feasible and within your personal agility limits, proceed further down to the Prickle Bed ledge near sea-level. In the past this was usually done by most visitors, including children, and used to require nothing but a short scramble down an easy, rather step-like, rock face. However, recent sea erosion has made it steeper and rather more difficult.
Once the blocks of stone were lowered from the working ledge they had to be transported to boats tied up against the seaward side of the lower ledge. The photograph above shows rutways described by Stanier (1996). He explained that they were purposely cut as routes for horn carts with curved shafts that were pulled by workers to move stone from the sites of the top cranes to the loading crane for the waiting boat.
In photographs above, the two main levels of Dancing Ledge can be seen. The lower ledge can be reached by carefully scrambling down some rock to the east, that is to the right of the cave in the centre of the picture. However, undercutting by the sea has now steepened the cliff (and produced a little overhang) and this is not as easy as it once was. The lower ledge has a very gentle slope controlled by the gentle dip towards the east.
These photographs are of the eastern part of the lower ledge, reached by an easy scramble from the main quarried ledge above. The swimming pool in the lower ledge was made for use of the pupils and staff of Durnford Preparatory School on the orders of the Headmaster who once owned this land.
(Footnote: Trev Haysome, the well-known Purbeck quarry owner, geologist and historian, told me a little more about the swimming pool. The owner and Headmaster at one stage had the pool painted white. He fixed a large steel mesh cover on the pool to prevent the common people from using it. However, one day he partly rolled the metal mesh back landwards to swim in the Dancing Ledge pool himself. A large breaking wave came in from the sea throwing him hard onto the steel mesh. The impact made patterned scars into his skin which he thouth would remain to his dying day.)
The origin of the lower ledge is a problem. It seems to be mainly the result of sea erosion rather than of quarrying because the Cherty Series here was not really of much economic use, until recent times (it is used now on the Isle of Portland and crushed for aggregate). There is a puzzle, though, because there do not seem to be large ledges of this type elsewhere on this stretch of coast. Usually there are small ledges or large boulders of fallen debris. Perhaps it is here because the dipping Prickle Bed or Puffin Ledge intersects sea-level.
All the stone from these quarries used to go out to sea in stone-transporting boats. These were strong, inelegant, flat-bottomed craft of about 7m in length which were towed to the site by ketch-rigged sailing barges, and were small enough to get inshore under the gibbets or whims. They were pointed at both ends and were normally rowed by two men with sweeps, although they did have a lug sail for use when conditions suited the ferrying of stone out to anchored sailing barges under sail. Though they were built very strongly, with oak frames and one-inch planks, such craft loaded with about six tons of stone did sink from time to time, whereupon their crews had to cling firmly to their buoyant wooden sweeps (
Bruce, 1989).
Examine the photographs again. The lower ledge is formed by Bed J', the Prickle Bed or Puffin Ledge, a notable thin unit in the Portland Cherty Series.
Arkell (1947) described this as follows: "The most conspicuous, easily recognised datum in the Cherty Series all along the cliffs. A comparitively soft chertless bed; weathering reveals a peculiar ropy structure reminiscent of lava and in places of pillow-lava; and a mass of ramifying forms probably due to algae [sic]. Behemoth [giant ammonites] at Seacombe and Winspit. "
Although they were once called "fucoidal" (like seaweed) in the old literature, the ramifying forms are not due to algae. Thay are Thalassinoides ichnofossils, the result of bioturbation by decapod crustaceans (crabs). Irregular cementation and compaction and perhaps some pressure solution has been involved in addition and accentuated the lumpy structure. Such features are typical of a carbonate sediment of very slow deposition, probably a hardground, of hiatus origin.
Larg worn ammonites are quite abundant in the Prickle Bed (J') of the main lower ledge at Dancing Ledge. They are usually not sufficiently well-preserved to see the full detail of ribs and are generally not identifiable. This is the basal bed of the Galbanites (Kerberites) kerberus Zone and has been correlated with the Basal Shell Bed of the Isle of Portland (
Wimbledon and Cope, 1978). This zone which continues up to the top of the Cherty Series contains Galbanites (Galbanites) galbanus, Galbanites (Kerberites) kerberus and species of Titanites including Titanites titan and Titanites giganteus. Thus, although this is the kerberus Zone, it would be wrong to think that there are no Titanites and that they only occur in the overlying Titanites anguiformis zone. Titanites anguiformis is larger and more finely ribbed than the other species of the genus and thus, according to
Wimbledon and Cope (1978) is easily recognisable in the field.
At the western end of the lower ledge there is a good view through a fairly long sequence through the upper part of the Portland Cherty Series succession. The scale is provided by a "tombstoner" (this is an unwise and dangerous activity because there are submerged rocks). The photograph has the main units of the upper Cherty Series listed. The most conspicuous bed is the Prickle Bed or Puffin Ledge, J', mentioned above. Here it is several metres above sea level so that underlying cherty limestones have been broken out by the sea and the ledge has collapsed. Other units of the Cherty Series can be seen here. The uppermost Cherty Series, beds M and N form the roof to the cave.
In these photographs the chert is shown more closely. In the left-hand image the chert is shown on the scramble route up from the lower ledge, near the Bathing Pool. The serpulitic chert in the right-hand image is in the Chief Serpulite, bed L. The serpulids, Glomerula gordialis, preserved in the chert, as are other fossils, show that it is replacive. Note that the chert looks much like the black flint in the Chalk but is rather coarser-grained and fractures in a more angular and less conchoidal manner. Like flint it is, of course, harder than steel; do not hammer it because it gives dangerous sharp splinters at high velocity and this can cause injury, even blindness.
Chert, of course, consists of silica in the form of chalcedony. It was probably originally opal but has undergone some crystallisation processes over the millions of years. It developed as nodules quite soon, in geological terms, after deposition of the lime sand, probably within about 5 to 10 million years (and perhaps much less). The evidence comes from the occurrence of Portland chert reworked into the Upper Purbeck Formation at Friar Waddon near Weymouth (West and Hooper, 1969). The Wealden sediments of the Lulworth area also contain detrital Portland chert.
The source of the silica was the abundance of small, reniform and opaline sponge spicules present in the limestones of the Cherty Series. The silica of these Rhaxella spicules has been replaced by calcite and the silica has migrated in solution to be precipitated as the replacive nodules. The main controlling factor was almost certainly pH. At high pH values, over about 9.4 (i.e. in alkaline conditions), silica is very soluble. Such high pH values are obtainable in water in contact with calcite (i.e. limestone) provided that the pCO2 (i.e. the content of dissolved carbon dioxide in the water) is very low. Thus the opal of the sponge spicules can dissolve and at any local centre with a slightly lower pH, such as where, for example, some organic matter is decomposing to produce carbon dioxide, there silica can be reprecipitated. Obviously, the details are more complicated and a factor of importance is that precipitation of a mineral on existing nuclei requires less energy than precipitation anew. Thus once nodules start to form they continue to grow as silica is preferentially deposited on them.
Just when the opal changed to chalcedony is not known. Temperature and time are probably the main factors (thus rocks with chalcedony are more likely to have been associated with oil source rocks that rocks with opal). In general opal persists (with some chalcedony) in strata of Cenozoic age. In Mesozoic strata the usual form of silica in nodules is chalcedony (of the varieties quartzine, lutecite and chalcedony sensu stricto). Because it is isotropic under the polarising microscope opal is not easily seen. It is, however, present in the Chalk as shown long ago by
Judd, although it is normally not seen (it can be found by dissolving chalk in acid). It is not known whether any persists in the Portland Group.
In the field most of the Portland sponge spicules,
the Rhaxella spicules are invisible. The branched spiny spicules of Pachastrella can be seen though. A good place to look is at the top of the Cherty Series in bed N at the seaward margin of the upper ledge (the quarried ledge) of Dancing Ledge. Look for white silicified calcarenite (like oolite) and examine a surface carefully with a hand-lens. Under a microscope the tubular structure of the now chalcedonic spines with a central canal is clearly seen.
Arkell (1947) refers to an abundance of Pachastrella in "silicified oolite"[silicified calcarenite] at St. Aldhelm's Head.
LOCATION:
- Green Point, East of Dancing Ledge
East of Dancing Ledge at Green Point a major extensional (i.e. normal) fault, probably of Late Kimmerian (Cimmerian) or Intra-Cretaceous age, displaces the Portland Stone. It has a throw of about 80 ft. or 24 metres, and this is the largest fault in the cliffs between St. Aldhelm's Head and Durlston Head. The fault upthrows on the east side. At this point part of the cliff is green with algae from water which runs over the top just here. There has also been some precipitation of travertine. The truncated valleys and the sea-cave features here are also of interest.
Notice the large fallen rocks to the right (east) of the Green Point Fault. The Portland Sand is above sea level, at the foot of the cliff here, and the fallen blocks are lying on this. It is common for Portland Sand outcrops in these cliffs to have such large fallen blocks of Portland Stone lying on them (cf. the Ragged Rocks).
LOCATION:
Green Point Waterfall - Runoff and Perched Aquifer
The Green Point Fault is the largest north-south, extensional fault between St. Aldhelm's Head and Durlston Head. It has a throw of 24 metres and is a normal fault with multiple fault planes and some fault drag. It extends several kilometres offshore to the south as shown on a geological map given above. It is one of many such extensional faults in the south Isle of Purbeck cliffs, including those of Kimmeridge. The age is not proven and their origin is still debatable. They could be sigma 3 responses to the south-north compression of the "Alpine" orogeny that formed the Purbeck faulted monocline. It might seem simpler to explain them as direct extensional results of the general Late Kimmerian (or Intra-Cretaceous or Sub-Albian) tectonics, but this may not have been confirmed as yet.
Ehe Green Point Fault has produced an interesting little example of both runoff and a perched water table, controlled by the location of the fault. This occurs on the downthrow (western) side and produces a small waterfall with green algae in the lower part. This is the origin of the name "Green Point".
A small stream seems to have shown uniclinal shift in a downdip direction, but has been limited by the fault plane (and Portland Stone outcrop on the upthrow side). Thus the small and ephemeral stream is located just west of the fault.
An additional factor is a small perched aquifer. The uppermost part of the Portland Stone in the area is the Shrimp Bed. This pelmicrite is quite well-cemented, and, although much fractured, it is probably of low porosity and permeability. It may act as an imperfect aquiclude. In addition the very basal part of the Purbeck Formation includes some thin carbonaceous clays (equivalent of the Lower Dirt Bed). These are too thin to be good aquicludes but undoubtedly hold up some water.
Above the partial aquicludes is calcitised anhydrite of high porosity and permeability. Above that is a limestone breccia, the Purbeck Broken Beds. It has probably been further disturbed by solifluction and cryoturbation during the late Pleistocene. Because of this the separation of the Broken Beds from solifluction debris is not easy on these hazardous cliff tops. On the current BGS geological map much of this Purbeck breccia is shown as "landslip".
The Broken Beds are tectonically brecciated evaporites, largely calcitised and subjected to dissolution by groundwater. The gypsum or anhydrite has been lost in solution leaving a porous limestone breccia. Such residual evaporite breccias are known in the Alps and Pyrenees cargneules. Those are usually reddish and dolomitic because they are often of Triassic origin. The lateral equivalent of the Purbeck cargneule consists of anhydrite. This has been found in boreholes, such as the Arreton Borehole on the Isle of Wight, and the calcium sulphate is commercially worked as gypsum in Sussex (Mountfield Mine). See the old papers of West for more on this topic.
The calcitised and brecciated Purbeck strata are very porous and permeable in the near-surface region. A dipping block of this is visible in the eastern part of the Dancing Ledge quarry. Water runs into this and seeps out at the fault, as shown in the diagram above. At some time in the past the water table in the cargneule has been higher and somewhere near its western limit there has been downward seepage and the development of a vertical cave or pothole (vadose). Other solution caves are likely to be present in this area, but as far as I know speleologists have not reported any. Several caves occur on the Isle of Portland.
LOCATIONS:
Further East of Dancing Ledge
The fault at Green Point brings up the top of the Portland Sand to the east. The hard dolomite beds (the Black Dolomites or "Black Sandstone" of Arkell) are at the base of the cliff and support fallen blocks of Portland Stone. The cliff here shows a complete succession of Portland strata, with the full Cherty Series (Dungy Head Member and Dancing Ledge Member) overlain by the Portland Freestone (Winspit Member).
For Blacker's Hole please go to the:
Anvil Point to Blacker's Hole Webpage.
LOCATIONS:
Hedbury Quarry, West of Dancing Ledge (SY 993768)
Hedbury Quarry is another old cliff quarry about half a kilometre west of Dancing Ledge. Unlike Dancing Ledge there is no easy access to the lower part of the cliff. The quarry is in Portland Freestone and has several galleries in the particular bed, the Under Freestone.
Back in 1953 I encountered the old cannon there, lying loose in the stone rubble at that time. It has since been mounted in a stone structure. It is not known whether it is from a defensive battery or from the wreck of the Halsewell, not far away. According to Stanier (1996) it is said to date from 1903. The cannon is now mounted on a plinth as shown in the lower (2007) of the two photographs above.
This quarry provides quite a good section of the basal Purbeck strata. Although this part of the section is inaccessible, being high in the cliff, it can be interpreted, in general terms, by comparison with other sections in the neighbourhood. The lower part of the Hard Cap (Top Cap of Portland) with stromatolites (thrombolites) is overlain by calcitised laminated anhydrite, probably of the upper Hard Cap (and roughly equivalent to the laminated and evaporitic Bacon Tier of the Isle of Portland). Above from about the level of the Soft Cap upwards there is rather soft, porous calcitised anhydrite (probably originally after gypsum). The Broken Beds are in this facies and show some typical evaporite-type contortions. Limestone breccia is not well-developed. Above the equivalent of the Broken Beds the base of the Cypris Freestone Member is visible. The general Purbeck sequence is like that at Fishermans Ledge (Conner Cove) and just north of Durlston Head.
MISCELLANEOUS:
Seal off Dancing Ledge
I would like to thank Ruth Brown, who has prepared an undergraduate project on the geomorphology of this area, for useful discussion in the field and assistance with the photography. I am very grateful both to Dr Clive Boulter and to Mr Gareth Lloyd for the use of photographs of the coast taken from the paddle steamer Waverley in 1997 and 1989 respectively. I enjoyed an opportunity to photograph the cliffs from the sea with a Bure Probus group from Mudeford in 2007. I am much obliged to Sheila Alderman for arranging an OUGS visit to Dancing Ledge in January 2010. I particularly thank George Raggett for assisting me by taking photographs from the now less-accessible, lower ledge. Trev Haysom, the quarry owner and expert on the quarries of Isle of Purbeck kindly provided much information on the history of the Dancing Ledge quarry.
Please go to Bibliography for St Aldhelm's Head to Anvil Point
Copyright
© 2010 Ian West, Catherine West, Tonya West 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 cancel 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:
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Ian West, M.Sc. Ph.D. F.G.S.
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