FOR LITERATURE REFERENCES RE. THIS WEBPAGE ON HORDLE CLIFF - GO TO: Highcliffe, Barton and Hordle - Bibliography

Hordle Cliff or Hordwell Cliff and its notable "Crocodile Bed" - Introduction

[Little is known about Eocene Noise: However, it is almost certain that the original swamps of Hordle Cliff, nearly 40 million years ago were disturbed "by the hoarse and deep bellowing of the alligator" (Owen and Bell, 1849-1858). The alligator also needs much heat, and there was no shortage of that at a time near the Middle Eocene Climatic Optimum. The Hordle Cliff location was once low swampy ground that was noisy, hot and dangerous, and not a good place for any mammal to visit. - Hear modern alligators roar on U-tube!]

Hordle Cliff consists of relatively soft, sand and clay cliffs of fossiliferous Upper Eocene strata on the English Channel coast of the south of England. They contain the well-preserved remains of turtles, crocodiles, mammals and Swamp-Cypress trees, that lived about 40 million years ago in a formerly warmer climate. Now there is rapid erosion of these fossiliferous strata. The longshore drift is from west to east, because of prevailing southwesterly winds. Sturdy sea-defences have been constructed over the years to give some protection to Barton-on-Sea to the west. Thus the beach sediment supply to Hordle Cliff has been cut off in the west. The consequence is the increased erosion here, down-drift (eastward), of the last groyne of the Barton sea defences, and more fossil remains are being exposed.
Hordle Cliff is well-known as the place where crocodiles were found by Barbara Rawdon Hastings, 20th Baroness Grey de Ruthyn, Marchioness of Hastings, whose estate was at Efford near Lymington, not far away. The "jolly fast marchioness", a very keen fossil collector and a geological author, found two fragile crocodile skulls on these cliffs in the 1840s, and presented her paper on them to the British Association for the Advancement of Science. The famous, Professor Owen, Director of the Natural History Museum, London, studied her notable discoveries and wrote: - "Whither trended that great stream, once the haunt of Alligators and the resort of tapir-like quadrupeds, the sandy bed of which is now exposed in the upheaved face of Hordwell Cliff?"

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[locator: two-black ]

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Compare the above photograph of Hordle Cliff in February 2018, with that of the same locality in June 2007. It is obvious that erosional activity is more active now and that the cliff-edge is likely to retreat further and destroy a substantial part of what cliff-top footpath that remains. There is much indication of both movement and of potential instability now, and there is very little vegetation on the present very active cliff. Compare to the only mildly active cliff, with more vegetation, shown in the older photograph. This coast naturally retreats anyway. However, the recent, increased activity is probably because the Terminal Groyne Syndrome, (i.e. erosion downdrift - southeast - of the Barton sea defences) is having more effect now.

Hordle Cliff, though, has, of course, long been retreating because it has very soft, easily eroded, cliffs facing a long southwesterly fetch. Atlantic waves can reach here in appropriate conditions. The cliff was once miles out to the southwest, and very, recently (in geological terms) the old coastal village of Hordle has been destroyed by the sea. Christchurch Bay overall should naturally be retreating evenly, but certain parts, such as the Barton and Highcliffe areas, are more strongly, artificially protected than other places. In contrast Hordle Cliff is eroding much more rapidly. Thus to a limited extent, the overall Christchurch bay might, perhaps, be tending, temporarily, to develop into two separate bays.

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Introduction - Fossils, general

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Fossil freshwater gastropods and bivalves are common in clays of the Headon Hill Formation. They still consist of the original aragonite shell, but usually the original colour, a natural organic dye, has been lost. Just occasionally some trace of the original colour can be seen.

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INTRODUCTION:

Safety

A major hazard at Hordle Cliff is of sinking into soft mud. It can be thinly covered by stones from the Pleistocene gravel or by some clumps of grass and then there is more risk of treading on it. In wet conditions it is wise to stay on the beach and study and collect from the lowest part of the cliffs.

Because of erosion and wet and slippery conditions it is not usually possible now to get up or down the cliff at Taddiford (Long Mead End), once a traditional locality for central access to the cliff of the Headon Hill Formation. Do not attempt it now. There are other access points, some way east and west.

There is a risk of being struck by a falling rock, pebble or lump of mud. This risk is greatest where the cliff is steep and being actively eroded. Safety helmets are recommended where such risk exists. Do not rest at the foot of a steep or hazardous cliff.

Landslides are common in the area, especially in winter. Generally these do not move fast and are more of a hazard to property than to people. Where the cliff is steep, however, a rapid and, therefore, a more dangerous fall is possible and care should be taken.

There is significant risk in standing close to the edge at the cliff-top. The Plateau Gravel which usually caps these cliffs often stands as a vertical face that is not secure and may collapse at any time and, in particular, erosion can produce dangerous overhangs of gravel capped by soil and grass. See that children are properly supervised.

Be prepared for possible wet or stormy weather conditions on the day of a field trip. Do not hammer flint pebbles because of risk of dangerous splinters.

Tide problems can be risk here, at certain places such as just SE of Taddiford Gap, so if possible, find out just when the tide is low or high. Do not take a chance of getting past a prominance when the waves are splashing up to it, or indeed when there is any risk of being caught by a wave.

Individual geological visitors and field leaders should make their own risk assessment and no liability for their activities is accepted here. The conditions are different on each day, and they are not obliged to go to any location shown here.

INTRODUCTION:

Maps and Locations

The car park at Taddiford Gap (three hour limit on the ticket?) has long been a convenient place to go to, when visiting Hordle Cliff. You can walk from here along a narrow footpath a short distance to south and to the cliff edge (the Taddiford Gap). As you go, you pass a Second World War gun emplacement on the east side of the path, just across the valley. When you reach the cliff you have a good view of the Hordle Cliff coast and you can usually see as far as the Needles on the Isle of Wight (vertical Chalk at the southern limit of the Hampshire Basin). At Taddiford Gap, , unfortunately, the informal route down the cliff has become eroded, and there are problems of steep parts and of soft mud. So from here, there is easy access to the top of the cliff top, but no easy access to the beach (although the conditions of the cliff can vary from extremely muddy, boggy and treacherous in winter to rather firmer and dryer in summer, but still without a well-defined path). This is the situation in 2018. Of course, no prediction, re access here, for the future is made. It is possible to reach the beach, in favourable conditions at Becton Bunny (less easy now because of erosion and can be closed) or at a car park, further east (usually easy).

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IINTRODUCTION:

Succession of Strata

The Headon Hill Formation (of the Solent Group) form part of the well-known Hampshire Basin, and is exposed at Hordle Cliff, west of Milford-on-Sea, in Christchurch Bay, and also at Headon Hill, the type locality near Alum Bay and Whitecliff Bay, in the Isle of Wight. The strata overlie the Becton Sand (Barton Sand) and Barton Clay. They are of Priabonian Stage of the Upper Eocene Series. In detail the strata at Hordle Cliff belong to the lowest part of the Headon Hill Formation - the Totland Bay Member. In terms of age in years these strata were deposited somewhere between about 38.6 amd 35.4 million years (Harland et al., 1982).

At Hordle Cliff there is a fascinating section of the Headon Hill Formation. It is mostly clay and marls with some sands, some ironstone nodules and very thin bed of limestone. Plant beds occur. Freshwater molluscs are abundant but remains of turtles, crocodiles, mammals, birds and even snakes are present.

From Hordle Cliff, with its excellent exposures of the Headon Hill Formation, there is a distant view of the Isle of Wight, shown here, somewhat enlarged. The Chalk cliffs, the stacks and the lighthouse are easily seen. These mark the southern boundary of the Hampshire (Tertiary) Basin. To the left of the Chalk are the vertical coloured sands of Alum Bay and to the left of those (actually to the northeast of them) is Headon Hill from which the strata of Hordle Cliff take their name. Hordle Cliff shows mainly the lower part of the Headon Hill Formation and has less limestone development than at Headon Hill. Vertebrate remain, particularly those of turtles, occur at both places but Hordle is better known for its important reptilian and mammal fauna.

GEOMORPHOLOGY:

Beach Features

This is a view at low tide on the 10 March, 2005 of an offshore sand bar and a narrow lagoon extending from near the site of the sewer jetty at Becton Bunny, eastward past Taddiford and on to Hordle Cliff and Paddy's Gap from where the photograph was taken. It continues further towards Milford. It does not seem to have been present many years ago and may be related to the realignment of the coast here resulting from the development of an embayment east of the sewer jetty (now a promontory protected by rock armour).

STRATIGRAPHY- SUCCESSION

- General

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[ N.B. Female reptile hunters.]
The photograph, next below, shows the relationship between the sideritic ironstone and the Crocodile Bed in the Headon Hill Formation at Hordle Cliff. If Barbara, Marchioness of Hasting was searching for crocodile bones, in about 1852, in the Crocodile Bed, then she was searching just underneath the "Ironstone Mynes" of Hordle Cliff, i.e. underneath from where sideritic ironstone was removed, perhaps to some extent by quarrying. If there was real quarrying then that might have been beneficial. This is all reminscent of, but later than, the activity of Mary Anning (1789-1847), collecting from the the coastal-quarried, Blue Lias limestones. The Marchioness was, of course, considerably wealthier than Mary Anning; both were great fossil experts and collectors and both knew the famous (top) geologists or palaeontologists, of the day.]

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The top left-hand diagram here shows the general succession of the Upper Eocene strata here with the major subdivisions indicated. The top right-hand diagram shows a medium level of detail in a vertical section by Tawney and Keeping (1883) . More detail and more recent information, with the use of modern palaeontological names, is available in a descriptive vertical section given by Edwards in an unpublished Ph.D. thesis. The photographs below show particular beds in the sequence which can be seen in the cliffs.

[LOCATOR - ACTIVE EROSION HORDLE, 2020]

STRATIGRAPHY:

Succession

- Headon Hill Formation - General

The strata consist of soft marls, clays and sands with some plant beds, some ironstone and some thin, poorly lithified limestone. They contain abundant, thin-shelled bivalve and gastropod remains, mostly of freshwater and lagoonal origin. Gastropods like Viviparus and Galba resemble modern pond-snails. Brown bones occur, and these include the remains of crocodiles, snakes, birds and mammals. Fragments of turtle carapace are perhaps the most likely to be found. Charophyte algae and blackened seeds of Stratiotes, a lake plant like the "Water Soldier" are common. The variety of the strata in terms of lithology and colour (sometimes yellow or pinkish) and the rarity of typical marine shells clearly distinguishes these strata from the drab, blue-grey Barton Clay. They are the deposits of lakes, lagoons and swamps of Florida-type at the end of the Eocene.

STRATIGRAPHY - SUCCESSION

- Headon Hill Formation - Biostratigraphy

The cliff section exposes the Totland Bay Member, the lowest part, of the Headon Hill Formation. The following notes are based on Edwards and Daley (1997), whose publication provides an important, recent, restudy of the cliff section. The sediments were deposited towards the end of the Eocene, the Totland Bay Member belonging to the Priabonian Stage (38.6 to 35.4 My - million years - Harland et al., 1989) of the Upper Eocene. It lies between marine horizons assigned to calcareous nannoplankton zones NP 17 and NP 19/20 ( Martini, 1971, and Aubry, 1986) and has yielded a Late Eocene Euzet mammal assemblage (Cray, 1973). On the basis of revised mammalian taxonomy, Hooker (1987, fig. 1) assigned the lower part of the Totland Bay Member to the stehlini-depereti concurrent range zone and the uppermost part to the vectensis-nanus concurrent range zone. On the same basis Brunet et al. referred the Member to their Reference-Level MP17.

LOCATION:

The Becton Bunny, stream valley and the Old Sewer Pipe Promontory

[Becton Bunny is east of Barton-on-Sea]

[this is area that is eroding in 2017-8; look at comparisons]

There has been appreciable retreat here in the ten years between 2007 and 2017.

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(see also the main Barton webpage and the Barton coast erosion webpage )

A conspicuous feature of the coastal topography is the small stream valley of Becton Bunny which is very oblique to the coast. This was originally known as Beacon Bunny, as shown in a cliff section, above, by Charles Lyell (1829). It probably named after the adjacent Beacon Cliff which probably once had a fire beacon.

In Beacon Cliff is the junction of the Barton Group exposed and the Headon Hill Formation. Becton Bunny is a convenient boundary and is an interesting place for major coast erosion at the eastern end (down-drift) side of the Barton sea defences. It is a place of terminal scour and of cleanly eroded cliff sections. There is easy access to the cliff top here from a car-park at the eastern end of Barton overcliff drive (western end of the golf course). The map reference is SZ 245928. Provided the coast path is not broken by erosion (and this is inevitable sooner or later) there is also access from Taddiford Gap, discussed below. The beach at Becton Bunny can be reached by walking from the main beach access at Barton-on-Sea (further west) or from Taddiford Gap, or, if the varying state of the cliff permits, scrambling down at the Bunny (probably inappropriate for a party).

Becton Bunny, incidently is an example of the chines which are developed in relatively soft strata on the coast of Bournemouth and the Isle of Wight. They are small steep-sided ravines incised into broader valleys. This incision is the result of rapid retreat of the coast so that the stream has become rejuvenated and cut down to adjust to the new cliff location. Unfortunately this particular chine is doomed to disappear in a while by the very rapid coast erosion, leaving just the upper valley, which extends across the golf course.

Examine these two photographs taken just over a year apart (September 2002 and October 2003). A steep or overhanging section of Pleistocene flint gravel is at the top. This is above sands and clays which mostly belong to the Becton Sands (Barton Sands) of the Barton Group (i.e. above the Chama Member and Barton Clay). The sands and clays are being rapidly eroded by the sea with some collapse and slumping. The cliff is unstable, oversteepened and retreating and it is important to keep away from the edge, which is often overhanging. There has been a bite-like retreat of the cliff-top in the year and erosion is moving rapidly in the direction of the Becton Bunny valley. The seats and path here clearly will not last for more than a few years.

The above photograph was taken in March 1998. The dark object seen projecting into the sea is the remains of a large sewer pipe, no longer in use at that time. In the 1950s from here to Becton Bunny the atmosphere was badly tainted by sewage odour, although if I recollect correctly seagulls were attracted to the offshore outfall. The pipe has formed a partial barrier to beach transport in recent years (previously the beach was further out and gravel could travel past it). Since the erosion has increased in this vicinity with the construction of the Barton sea-defences it has been reinforced with blocks of limestone so as to form the most easterly strongpoint of the Barton area. This is a barrier to the easterly long-shore drift. Thus with limited, protective, beach shingle available to the east of it a new embayment has been created and this continues to be eroded.

This photograph was taken in October 2003. The remains of the pipe seem to have gone and there has been some erosion of the promontory. The coast still projects because the strongpoint gives protection. There is still increased erosion to the east (down-drift) of this strongpoint and there seems to be some detectable affect on the coast from here to Taddiford Gap. The enhanced coast erosion has provided a good exposure of the upper part of the Becton Sand Formation (Barton Sands). The black Lignite Beds (L), which are at the top of the Becton Sand, are easily recongnised features. These lie beneath the basal part of the Headon Hill Formation ( Mammal Bed etc) and descend in the cliff eastward towards Taddiford Gap where they are near the beach level. Thus, to the east of here the lower part of the Headon Hill Formation descends and eventually, at Hordle Cliff east of Taddiford Gap, comes to occupy almost all the cliff.

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Compare the above photograph, taken on the 26th June 2015, with old photographs (above) of this same promontory. This is a notable locaton. In the 1950s it was one of the worst smelling places on the local coast and you really could stay there very long. I personlly thought that it smelt much worse than even the East Cliff beach of Bournemouth which was then affected by the more distant raw sewage discharge off Bournemouth Pier. There is now an intercepting, sewage treatment plant up the Becton Valley and this little headland is now no longer a problem location.

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Beacon Cliff, East of Becton Bunny

- Introduction

Beacon Cliff is an actively eroding cliff between Taddiford Gap (Long Mead End) in the east and Becton Bunny (original name - Beacon Bunny) in the west. Because of the obliquity of Becton Bunny and appreciable cliff erosion this cliff has lengthened from east to west with time. In the early 19th century it quite short, as shown in a cliff section by Charles Lyell (1829), because Taddiford Gap and the mouth of Becton Bunny (very oblique to the coast) were quite close. The prominant headland between the two valleys, easily seen from the Isle of Wight and elsewhere, was probably a good place to site a warning fire beacon in the 18th century or a little earlier. This cliff probably did not exist, however, in the 16th century because at that time Long Mead End and Becton Bunny would probably have been joined.

LOCATION - STRATIGRAPHY:

Beacon Cliff -
Bed J - Becton Bunny Bed - Clay ("Oliva branderi Zone")

LOCATION - STRATIGRAPHY:

Beacon Cliff - Shell Bed, Lignite Bed and the Becton-Headon Junction

These is well-seen in Beacon Cliff and particularly just to the west of Taddiford Gap. The double lignite bands provide an excellent marker for the Becton Sands (Barton Sands) - Headon Hill Formation junction.

Under the lignite beds there is shell bed with numerous cerithid gastropods, mostly Batillaria pleurotomoides. See Demassieux (undated) for more information on this species. It occurs in several places in the Tertiary strata of France.

Batillaria of different species are common in intertidal conditions in warm to temperate regions at the present day. Batillaria minima is the Caribbean/West Indian False Cerith. They occur, for example, in Spital Pond, Bermuda where the shells are off-white to black and the bodies black. Batillaria zonalis is the Zoned Cerith or Asian Horn Shell. The subject of Batillaria is easily followed further because there is much information on the internet.

LOCATION - STRATIGRAPHY

Beacon Cliff and Taddiford Gap
- Mammal Bed

The Mammal Bed with rather round, ironstone nodules near its base is well-exposed and accessible in Beacon Cliff. It can also be seen in the basal part of the cliff at Taddiford Gap, and a short distance further east.

Tawney and Keeping (1883)referred to their unit No. 9, as shown in the section above, as the Mammal Bed and listed its thickness as 3.8 metres. In 1883 they commented that they found a Dichobune mandible (this mammal was a swine-like artiodactyl) on their last visit, but that mammals had seldom been found in about the 1870s or 1880s. The Marchioness of Hastings stated that she obtained from the Mammal Bed, or near it, the following:

Anthracotherium
Anoplotherium commune (this is an archaic tylopod - i.e. old distant relative of the camels and lamas - artiodactyls)
Paloplotherium
and also the remains of the turtles - Trionyx and Emys. She found the bones of birds. The Marchioness commented that "the remains are not common and difficult to extract".

As noted on the photograph, the vertebrae of snakes occur under the ironstone. Above it are the vertebrae of lizards, and teeth of mammals and fishes, crocodiles and turtles.

I have only seen one large Palaeotherium limb bone in the Mammal Bed. This early equoid had three toes and some species reached the size of a rhinoceras at about this date. It seems to have been a rather heavy horse-like creature. The group became extinct later and was not on the main line of horse evolution. The Marchioness found an associated set of Palaeotheriod bones in the carbonaceous clay - Bed 10 of Tawney and Keeping (1883).

For up-to-date information see the modern literature on mammals from these strata in the papers of Hooker (1986 and various others). These are referred to in the Barton Bibliography.

LOCATION-STRATIGRAPHY:

Beacon Cliff - Old River Channel

In Beacon Cliff, commencing just to the west of Taddiford Gap, is old Eocene river channel cut into Headon Hill Formation strata. It contains abundant lignitic plant debris.

LOCATION - STRATIGRAPHY:

Beacon Cliff - Pleistocene Gravel

(section to be added)

LOCATION:
TADDIFORD GAP (LONG MEAD END) - General

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Taddiford Gap, or Long Mead End, as it is referred to in the older literature, is a small truncated valley reaching the sea at Hordle Cliff. Note that in early 2019 there is no safe access to the beach here; there has been both coast erosion and landslipping with treacherous soft mud. It might dry out again in the summer, but there is no certainty of a safe path to the beach here in the future. The beach here can easily be reached by walking at low tide from Milford-Hordle car park in the ESE. It can also be reached in favourable conditions from the Becton Bunny area to the west. No guarantee is made that at any particular time there is safe access to this locality as the cliff, the tide and wave conditions will vary. Assessment has to be made at the time of a potential visit.

The Taddiford Gap (or Long Mead End) cliff section and its vicinity is probably the best place to make a study of the Headon Hill Formation in the cliff section. The Crocodile Bed, the Mammal Bed and other notable features of this part of the Solent Group can be seen just here. By walking eastward from Taddiford Gap the Upper Barton Beds, the Barton Sand or Becton Formation is seen in well-exposed, eroded cliff sections. Walking eastwards will reveal somewhat slumped and overgrown sections of the higher parts of the Headon Hill Formation. The locality is also interesting for the study of coast erosion and the more distant effects of sea-defences.

[Notes made in the past when there was easy access at Taddiford Gap, and they may not apply now.
"Drive down the B3058 to the car park (map reference SZ 265925 - Ordnance Survey Outdoor Leisure Map, New Forest 1:25000) near Taddiford Farm between Barton on Sea and Milford on Sea. This a payment car park and there is a short and easy walk (less than half a kilometre) to the cliff top at Taddiford Gap or Long Mead End. Note that there are no toilets here but these are present at Barton and Milford. There are no cafes or shops at hand to obtain food and a visiting party might find it useful to stop at Barton or Milford in advance." ]

At the cliff top the general geological setting can be discussed (more information to be provided here later). The main danger here is of getting stuck in the mud. Risk from falling debris exists at all cliffs but is not as serious a problem here as at harder rocky cliffs. Watch out for mudslides or mudflows. You are unlikely to sink deep but you can be trapped in cold mud and water for hours. Helicopters and fire-brigade have been involved in rescues on these cliff and, on one occasion, I have pulled a nun out of the mud at Barton.

There is an interesting situation here of a valley, with the Danes Stream, sloping away from the sea so that any coastal retreat will result in a lowering of the cliff here. Only four kilometres to the east the stream flows back to the coast again at Sturt Pond and Hurst Castle Spit (think about the reasons for this). Water flows through the gravels, particularly on the west side of the depression (why?) , and there are special flood protection measures in the valley to the northeast (inland).

Additional note - 2003. As mentioned above in the safety section, there has been erosion of the cliff at Taddiford or Long Mead End and at times it may not be easy to gain access to the beach here. The state of the cliff varies, of course, but increased erosion in the future is likely the make the situation more difficult here and, in addition, the coastal footpath may be cut through. Usually, though, there are other access point at a short walk both east, towards Milford, and west near Becton Bunny.

LOCATION:
Taddiford Gap - Coast Erosion

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Comparative photographs from 1998, 2003 and 2015 are shown here. In the top, older photograph, if you look west of the Taddiford or Long Mead End valley you can see that the old footpath has been cut through in places and a new footpath has been established further back. The cliffs here are retreating at a progressively greater rate further west towards Becton Bunny. The two "Dragon's Teeth" are relicts of a row of anti-tank defences against invasion by the Germans in the 1940s. In various places the relics of the military defences of the 1940s are quite useful to show the extent of coast erosion. The survival of the dragon's teeth show that erosion from the 1940s to 1998 had been quite limited here to beyond that year (but compare with the gun emplacement at Naish Farm ). By 2003, though, erosion had increased and now we see the collapse of the dragon's teeth and a significant narrowing of the beach. In addition there is exposure of siderite nodules referred to below.

By 2015 the access to the beach has become difficult and may be impossible in wet weather conditions. Look at the photograph above. I descended and ascended without a problem in very dry weather conditions of June 2015. When the clay is wet it may not be possible to readily maintain a foothold on it. Erosion might steepen the section to a cliff that gives no access to the beach. A notice board suggests that there is no access. This is not a place to take a field party down.

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In an old photograph above, Environmental Geology students from Southampton University were assessing the variation in the extent of coast erosion along the stretch of cliff immediately east of Becton Bunny (and west of Long Mead End). They are standing on the remains of some concrete foundations (for what?), part of which has disappeared over the cliff. The main feature to see just here is a new embayment formed since sea-defences at Barton-on-Sea, west of here, were constructed many years ago.

The beach material normally comes from the Pleistocene gravels in these cliffs as they evenly retreat. Prevailing south-westerly winds cause the waves on the shore to wash it along the beach from west to east. This coast has changed significantly if comparison is made between old and modern maps or, perhaps, old and modern photographs. Consider whether the natural supply and movement of beach shingle been reduced or stopped by the sea-defences of Barton-on-sea and/or by a projecting sewer pipe and wall near the small valley of Becton Bunny. If the supply of beach material is cut off or diminished the beach is likely to reduce in width and the potential for coast erosion increases. The process of increased erosion at the end of sea-defences in the direction of long-shore drift is known as terminal scour.

The present author has known this stretch of coastline since the 1950s when the coast here was relatively straight. The rate of erosion near Becton Bunny has become much more pronounced in recent years and this is now a good area for seeing clean exposures of the strata with good fossil content. The cutting-back has formed a new embayment between Becton Bunny and Taddiford (Long Mead End).

LOCATION:

Taddiford Gap - Coast Erosion - Recent Loss of Beach Shingle

[recent photograph]

[some old photographs follow]

The photographs here record a new phase of coastal erosion at Taddiford. The base of the shingle beach is knotched with obvious wave erosion and siderite (ironstone) nodules are revealed.

With regard to the history of this site, the best vertebrate finds at Hordle Cliff seem to have been made in the 19th century and include a crocodile skull. It thus seems likely that the cliff was undergoing appreciable erosion at that time. Much later, in the 1950s the present author was familiar with the beach at Taddiford and it was of moderate width. The erosion of the cliffs was limited here but it was still possible to find some crocodile bones in the crocodile bed. After this phase and later in the 20th century there was an expansion of the width of the beach at Taddiford and the crest of the berm was some way out from the foot of the cliffs. There was clearly some realignment of the beach which may or may not have resulted from the construction of sea-defences. Towards the end of the 20th century the erosion was very marked at Becton Bunny, as mentioned, but it did not affect Taddiford. The new development now, and one that has taken place since 1998, but has only recently been seen by the author, is this exposure of siderite (ironstone) nodules as a result of erosion of the foot of the beach. Destructive-type waves were in progress at the time of photography and the relative lack of storm conditions in the dry summer of 2003 might have increased this type of erosion. Nevertheless it is a clear sign of increased erosion here, and this seems to be confirmed by the retreat of the cliff top and a relatively narrow beach at present. It is probable that this is extension eastward of the area of major cliff erosion that is east of Becton Bunny. This is presumably the result of progessive loss of beach material. No investigation has been made by the writer (although others might be studying it). The long-term implications are not known but this clearly something to watch. The general situation in October 2003 is that the cliffs to the east of Taddiford Gap or Long Mead End are not showing much erosion (other than within a 100m of the gap). They are quite vegetated, unlike the cliffs to the west. We will see what effect the forthcoming winter storms have on this stretch of coast.

The nodules are ex situ and probably represent the boulder base of the beach. There are three main ironstone horizons in the cliff and no study has yet been made to determine which was the source bed. Of course, more than one horizon may have contributed material which fell from the cliffs. The most likely source, though, is probably the well-developed Mammal Bed ironstone.

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Iron Scaffolding Sea Defences

At the low spring tide on 10 March 2005 more siderite (ironstone) nodules were found ex situ in a narrow lagoon low on the beach. This is also just east of Taddiford Gap and these represent accumulation from some former position of the cliff here, perhaps about 100 years or more ago. A short distance further east there are remains of iron scaffolding from military defences against German invasion, a relic of the second world war. Shown above is a notice about this, present in a Hordle Cliff car park in February 2016. This again indicates that there here, a hundred metres or so east of Taddiford Gap, there has been some renewed retreat of the beach and cliffs. After a long, almost static phase, erosion in this region seems to be restarting.

Incidently the accessibility of ironstone here at different times in the past might have some relevance to historical or archaeological investigations regarding local use of siderite (as at Sowley Pond). Ironstone is now less visible that is usually the case at Hengistbury Head, but this Hordle Cliff ironstone is becoming increasing visible. A difference between the two is that the Hengistbury ironstone contains glauconite and rare marine fossils. The ironstone here is more likely to contain freshwater fossils. I doubt if it contains glauconite but I have not investigated this matter.

This Cliff is in perpendicular height about fify yards from the sea, at high water mark and extends about a mile and a half along shore; it is composed chiefly of red gravel, to about 18 or 20 yards below the surface [anomalously thick], but amongst the gravel very few shells or remains of marine bodies are to be found.

In many parts of the Cliff there are large veins, or rather masses, of a mouldering soft blue clay, through land springs are continually trickling down, which by degrees loosens the clay and causes it to slide away in great beds, one below another, and the frost may not a little contribute to this effect. So that the surface has in a few years been greatly worn away.

When the fall of this Cliff happens there then found perhaps the greatest variety both of the turbinated and bivalve shells that were ever met with in any one place in the world, in their original state, and have suffered no change for innumerable ages past, this so remarkable a circumstance may be dayly verified by inspecting the cabinets of the curious.

Many of the shells are the natural inhabitants of very distant regions, and some of them entirely unknown, either in their natural or fossil state.

towards the bottom of this Cliff there are frequently found large nodules of a hard reddish ironstone or marble [this is the Shell Bed or Stone Band (G) at the top of the Barton Clay], being no other than an entire mass of shells, with which the church [presumably the church at the original cliff top village of Hordle, now destroyed by the sea] and other edifices are built.

ACKNOWLEDGEMENTS

I am grateful to the various students and the members of my family who have worked with me on field trips or projects in this area. I am particularly grateful to the Director and staff of the The Channel Coastal Observatory for permission to use their excellent, vertical aerial photographs.

BIBLIOGRAPHY AND REFERENCES

Re Hordle Cliff, see also the closely related webpage for the stretch of coast immediately to the east.

Milford-on-Sea, Erosion and Sea Defences

Questions and Exercises [to be expanded]

1. Compare and contrast the former living environments of the two, well-known, ancient British crocodiles, the Cretaceous Swanage Crocodile and the Eocene, "Hampshire Crocodile" (Diplocynodon hantoniensis) the remains of which are present at Hordle Cliff, Milford-on-Sea. Incidentally, now that the local climate is relatively mild again, do you think it feasible for the re-introduction of a new "Hampshire Crocodile", imported from Florida, to a closed-off, small part of the Solent as a tourist attraction?

2. The freshwater or low-salinity molluscs of the Headon Hill Formation are generally very thin-shelled. Were these shells mainly of aragonite or of calcite? What type of molluscs usually now and in the past have shells of calcite? ----- (more to be added)

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