West, Ian, M. 2020. Hordle Cliff, Becton Bunny, and Beacon Cliff, Hampshire, Headon Hill Formation: Geology of the Wessex Coast of Southern England. Internet site: www.southampton.ac.uk/~imw/hordle.htm. By Dr. Ian West, Romsey, Hampshire, and Visiting Scientist at the School of Ocean and Earth Science, Southampton University. Modified version: 11th August 2020. Updated.
Hordle Cliff, Hampshire, Geological Field Guide, by Ian West

Ian West,
Romsey, Hampshire

Visiting Scientist at the Faculty of Natural and Environmental Sciences,
National Oceanography Centre,
Southampton University,
Webpage hosted by courtesy of iSolutions, Southampton University
Aerial photographs by courtesy of The Channel Coastal Observatory , National Oceanography Centre, Southampton.

See also the closely related webpage for the stretch of coast immediately to the east.


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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?"


Pleistocene gravel over clays and sands of the Eocene, Headon Hill Formation Hordle Cliff, Hampshire, with a dog, 22nd February, 2018


Looking southeast from the cliff top, at a landslide and mudslide, developing just west of Taddiford Gap, Hordle Cliff, Hampshire, and still in progress of extension, 22nd February, 2018

General environment at Hordle Cliff, Hampshire - a large sea bird that has just been down on the waves, 28th July 2020

Upper part of a landslide and mudslide developing just west of Taddiford Gap, Hordle Cliff, Hampshire, and likely to extend further landward and perhaps cut the cliff-top footpath, as seen on 22nd February, 2018

At the top of a landslide and mudslide, a new fissure in the Headon Hill Formation at the top of the cliff, just west of Taddiford Gap, Hordle Cliff, Hampshire, at a place where there is no Pleistocene gravel, 22nd February, 2018

Lower part of a landslide and mudslide, developing just west of Taddiford Gap, Hordle Cliff, Hampshire, as seen on 22nd February, 2018


Terminal scour at the downdrift side of rock-armour, sea defences, cliffs at Barton Golf Course, east of Barton-on-Sea, Hampshire, southern England, GE image


Collapsing cliff, with brick and concrete debris, at a small promontory of rock armour at the Sewer outfall promontory, at the eastern end of Beacon Cliff, between Barton-on-Sea and Hordle Cliff, Hampshire, southern England, 22nd February 2018

Terminal Groyne Syndrome seen at beach level, a small promontory of rock armour at the Sewer outfall area retards shingle movement,  at the eastern end of Beacon Cliff, between Barton-on-Sea and Hordle Cliff, Hampshire, southern England, 22nd February 2018

Terminal Groyne Syndrome effect, a new collapse of the Barton Sand in the cliff just east of the eastern end of the Barton sea defences near Becton Bunny, between Barton-on-Sea and Hordle Cliff, Hampshire, southern England, 22nd February 2018


A collapsing cliff-top at the western end of Hordle Cliff, near to Becton Bunny, Hampshire coast, 22nd February, 2018


Hordle Cliff, seen from the southwestern end, looking southeastward on the 22nd February, 2018, and showing that erosion and retreat of the cliff is very active


A general view of Beacon Cliff, looking southeast in the direction of Hordle Cliff, 10th July 2020, when weather conditions were warm and still, and there was no active erosion


General view eastward from near Becton Bunny towards Hordle Cliff, Hampshire, June 2007

[locator: two-black ]

Details of a double sequence of thin black lignite beds, at the Becton Sands - Headon junction, just southeast of Becton Bunny, between Barton and Hordle Cliff, 2nd October 2019, Ian West

Beacon and Hordle Cliffs, looking southeastward on the 10th September, 2019, and showing active erosion, but also with some vegetated patches surviving


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.

Active erosion at high tide at a location immediately west of Taddiford Gap that was impassable at the time

Hordle Cliff shown on a map of 1969 when beach access from Milford-on-Sea was much easier

General view of the Headon Hill Formation at Taddiford Gap, Hordle Cliff, Hampshire in 2003

West side of Taddiford Gap, Hordle Cliff

Crocodile Bed at Hordle Cliff, Hampshire


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Introduction - Fossils, general


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.

Potamomya plana or Erodona plana (J. Sowerby), a freshwater bivalve from the Headon Hill Formation of Hordle Cliff, Hampshire

The bivalve Erodona plana (J. Sowerby) or Potamomya plana from the Headon Hill Formation of Hordle Cliff, Hampshire, compared to a modern, living example of Erodona

The freshwater gastropod, Viviparus lentus from the Headon Hill Formation, Upper Eocene, just west of the White House at Milford-on-Sea, Hampshire, and at the eastern of the Hordle Cliff

Seeds of the Water-Soldier or Water Aloe, Stratiotes, just below the Unio Bed, east of Hordle Cliff, Hampshire

The common, fossil, pond-snail or freshwater gastropod, Viviparus lentus in the Headon Hill Formation of Hordle Cliff, Hampshire


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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.

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Maps and Locations

Topographic and location map for the geology of Hordle Cliff, Hampshire

Taddiford Gap, car park, which gives access to the cliff top above Hordle Cliff, but, no longer, any very easy access to the beach

East of the path from the Taddiford Gap, car park, to the clif top at Taddiford Gap, you pass an old gun emplacement of the Second World War

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).

An aerial overview of the coast at Hordle Cliff, Beacon Cliff and Milford-on-Sea, Hampshire, giving location and erosion information

Cliff west of Taddiford Gap, Hordle Cliff, Hampshire

General view of the Headon Hill Formation at Taddiford Gap, Hordle Cliff, Hampshire

A map of Hurst Spit, Milford-on-Sea, Lymington and Sowley areas in 1740, showing locations of ironstone mining and iron ore production

The ironstone at the Hordle, Hordel or Hordwell Cliff  showing the location of ironstone mining in 1740, except that because of subsequent erosion the cliff and beach has retreated landwards, of course


The sequence about the lower ironstone in the Headon Hill Formation, Hordle Cliff, with comparative details re the succession


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Succession of Strata

Barton-on-Sea, Hampshire

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.

The Needles and Headon Hill, Isle of Wight, seen in the distance from Hordle Cliff, Hampshire

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.

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Beach Features

Lagoon and bar at low tide at Hordle Cliff, Hampshire, seen from Paddy's Gap, 10th March 2005

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).

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- General

Succession, Barton and Hordle

The Hordle Cliff succession, redrawn but based on Gardner, Keeping and Monckton, 1888, Fig 4 - Section through the Lower Headon at Hordwell,

The main cliff section to the ESE of Taddiford Gap showing the Crocodile Bed and other strata, Hordle Cliff, Hampshire, 2019

Vertical section of the Headon Hill Formation at Hordle Cliff, according to Tawney and Keeping (1883)


[ 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.]


Exposure of a section including the Crocodile Bed and the Limnean Limestone, east of Taddiford Gap, Hordle Cliff, Hampshire, 2007


West side of Taddiford Gap, Hordle Cliff

Hordle Cliff succession as seen in 1998

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.

Very active erosion, to the eastsoutheast of Taddiford Gap, Hordle Cliff, as seen in July 2020


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- 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.

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- 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.

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The cliffs discussed here are in the eastern part of Christchurch Bay, on the coast of Hampshire, south of the New Forest. They are easily reached from Barton-on-Sea or Milford-on-Sea and are a short drive from the larger towns of Bournemouth and Southampton. Locations are considered in this webpage from west to east, that is from Becton Bunny, near Barton-on-Sea to the main Hordle Cliff section (Taddiford Gap etc) and then to Rook Cliff at Milford-on-Sea. Passing reference is made to Hurst Castle Spit at the far eastern end of Christchurch Bay.

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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]

The mouth of Becton Bunny, between Barton-on-Sea and Milford-on-Sea, Hampshire, 2007

Collapse of gabions at the Becton Bunny chine, east of Barton-on-Sea, Hampshire, the result of coast erosion, as seen on the 16th December 2017, Ian West

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


Sand Martins, Ripari riparia, with holes in the Long Mead End Bed of the Barton Sands (Becton Sands), Becton Bunny, near Barton-on-Sea, Hampshire

A section from Becton Bunny to Hordle Cliff, Hampshire, sketched by Charles Lyell in 1829

(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.

Erosion west of Becton Bunny, Sept 2002

Erosion west of Becton Bunny, Oct  2003

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.

Promontory at position of old sewer pipe, east of Becton Bunny as seen in March 1998

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.

Promontory at position of old sewer pipe, east of Becton Bunny, 2003

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.


The promontory at the old sewer pipe, east of Becton Bunny and west of Hordle Cliff, Hampshire, as seen on the 26th June 2015

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, between Becton Bunny and Hordle Cliff, Milford, Hampshire, with a good exposure of the Barton Sands - Headon Hill Formation junction

Wreckage of a container, probably from the container ship, Napoli, present at Beacon Cliff, near Barton-on-Sea, Hampshire

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.

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

A general view of the Becton Bunny Bed, J, at the base of Beacon Cliff, near Milford-on-Sea, Hampshire

The bivalve Glans oblonga in the Becton Bunny Bed of the Barton Sands (Becton Sand), Beacon Cliff, near Milford-on-Sea, Hampshire

Iron springs flowing out over the Becton Bunny Bed (clay), Barton Sands, at Beacon Cliff, near Milford-on-Sea, Hampshire

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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.

The two lignite beds at the junction of the Barton Sands and the Headon Hill Formation, Beacon Cliff, west of Hordle Cliff, Milford-on-Sea, Hampshire

Batillaria shell bed at the top of the Long Mead End Sands, Bed K, at Beacon Cliff, near Hordle Cliff, Hampshire

Batillaria concava shell bed at the top of the Long Mead End Sands, Bed K, at Beacon Cliff, near Hordle Cliff, Hampshire, a later view

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.

The Dwarf Olive Shell, Olivella branderi from near the top of the Eocene Becton Sand in the cliffs west of Taddiford Gap, Hordle Cliff, Hampshire

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Beacon Cliff and Taddiford Gap
- Mammal Bed

Excavation in the Mammal Bed, Headon Hill Formation, Eocene, east of Taddiford Gap, Hordle Cliff, Hampshire

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:

Anoplotherium commune (this is an archaic tylopod - i.e. old distant relative of the camels and lamas - artiodactyls)
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.

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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.

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Beacon Cliff - Pleistocene Gravel

(section to be added)

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The junction of the Becton Sand, formerly called the Barton Sand, with the Headon Hill Formation, at Taddiford Gap, or Long Mead End, Hordle Cliff, in 2019


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.

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Taddiford Gap - Coast Erosion

Long Mead End or Taddiford Gap as seen in 1998

Changes at the Taddiford Gap or Long Mead End, Hordle Cliff, from 1998-2019, comparison


Students at the dragon teeth at Taddiford Gap (Long Mead End)

In 2019, the dragon teeth at Taddiford Gap are in the sea

Details of the concrete dragon teeth in the sea at Taddiford Gap, Hordle Cliff


Long Mead End or Taddiford Gap as seen on 19 October 2003


The former path to the beach of Hordle Cliff at Taddiford Gap had been eroded away by 2015, but in dry weather it was still possible to descend


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.


Terminal scour east of Becton Bunny

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).

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Taddiford Gap - Coast Erosion - Recent Loss of Beach Shingle

[recent photograph]

It is often, but not always, possible to walk to Taddiford Gap from the east, but the beach is narrow now, and you may get wet

[some old photographs follow]

Siderite nodules exposed by retreat of beach near Taddiford, Hampshire

Destructive-type waves exposing siderite nodules under the beach near Taddiford, Hampshire

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.

Lagoon and bar at Hordle Cliff, Hampshire, seen from Paddy's Gap

Siderite nodules in a lagoon seen at low spring tide, 10 March 2005, just east of Taddiford Gap, Hordle Cliff, Hampshire


Iron Scaffolding Sea Defences

A warning notice at a car park on Hordle Cliff of the exposure on the beach of relics of iron scaffolding, military defences of the Second World War, east of Taddiford Gap,  Hordle Cliff, Hampshire

Remains of iron scaffolding, military defences of the Second World War, east of Taddiford Gap,  Hordle Cliff, Hampshire

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.

The colour of the nodules on the shore is dependent on the extent of former weathering in the cliff and the amount of erosion. Fresh siderite, FeCO 3 , is bluish-grey, but it partially weathers in oxidising meteoric water with the production of some brown goethite, the ferric hydroxide. In extreme conditions of weathering it can oxidise completely to goethite (limonite) but that is not frequently seen. A nodule on the left of the right-hand image shows the brown and rather weak crust, but most show fairly unoxidised siderite.

Apparent narrowing of the shingle beach at Taddiford Gap, Hordle Cliff, Hampshire, from 2003-2007

If comparison is made of the relative positions of old concrete, World War 2, defences, the beach at Taddiford seems to have narrowed appreciably from 2003 to summer 2007. In addition there has been a fairly recent landslide (sometime from summer 2006 to summer 2007?) at the eastern end of this gap. Further west the Becton Bunny Bed (clay) is very well exposed and is clearly undergoing erosion. The changes are not as yet very drastic, but a new phase of increased coastal retreat might be commencing. The shingle beach between Becton Bunny and Milford seemed to be diminishing from west to east. Later, in 2016, there has been significant erosion in parts of Hordle Cliff, but mostly near the White House at Milford-on-Sea

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Taddiford Gap - Temporary Increase in Cliff Vegetation

Increase in vegetation growth on Beacon Cliff, west of Taddiford Gap, near Hordle Cliff, Milford, Hampshire

As the photograph above show, there has been a major increase in growth of vegetation at the eastern end of Beacon Cliff from 1998 to 2007. The western part of Beacon Cliff is undergoing erosion and cliff falls and is generally bare of vegetation.

The eastern part has had a previous phase of erosion and cliff-collapse but this ceased many years ago. The cliff here then stabilised at the back of a large shingle beach. The development of vegetation on the middle to upper cliff is probably in part due to the stability and in part due to the warmer and wetter climatic conditions of this region, perhaps associated with global warming.

The cliff may not remain long in vegetated form. The beach has now greatly reduced in width, with loss of shingle, and a new phase of cliff collapse seems to be commencing. Much of the vegetation may be destroyed by new landslides as erosion increases in eastern Christchurch Bay.

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Taddiford Gap

Looking eastward at Taddiford Gap, Hordle Cliff in hot, dry weather, 10th July 2020

Here at Taddiford Gap, the Headon Hill Formation is well-exposed. You are warned that in wet weather or after rain, the cliffs here may be dangerously boggy with soft clay, and, then, there may be no safe route down to the beach. Even in dry weather, much caution is needed in trying to get to the beach (in the past, it has been easier at times). Do not take a risk if the cliffs are very muddy or you are uncertain about finding a way down.


- The Crocodile Bed [with the rare occurrence of bones of the Eocene crocodile: Diplocynodon hantoniensis] The location of the Crocodile Bed in the Headon Hill Formation, in about the middle of the cliff, to the east of Taddiford Gap, near Milford-on-Sea, it is not easy to find bones here

Alligator skull from the Crocodile Bed of Hordle Cliff, Hampshire, after Owen and Bell, 1849-1858

Crocodile Bed at Hordle Cliff, Hampshire


Alligator skull from the Crocodile Bed of Hordle Cliff, Hampshire, after Owen and Bell, 1849-1858

Modern crocodile head , photographed by Kyaw Tun, and shown for comparison with the fossil remains of the Hampshire Crocodile from the Crocodile Bed of Hordle Cliff, Hampshire


Crocodile vertebrae and a tooth from Hordle Cliff, Hampshire

The Crocodile Bed,15b, is an easily-recognised, very fine sand, weathering whitish. It originally received the name "Crocodile bed" by Wright in 1851. Most of the bones were found in the 1840s including a fine skull. I was still able to find crocodile vertebrae like those above just east of Taddiford Gap in the 1950s, although they were rather delicate and needed excavating with care and then hardening with a resin. Edwards and Daley (1997) commented that extensive excavations in the outcrop midway between Hordle House School and Taddiford Gap ( Hastings, 1853) yielded abundant scales of the ganoid fish Lepisosteus fimbriatus (Wood) and much less common skulls, dermal scutes and post-cranial bones of a crocodilian. Also present were trionychid (i.e. like Trionyx) turtle carapaces and mammalian remains. The fossils occurred in greenish mud lenses, at approximately 0.60m below the top ( Tawney and Keeping, 1883). A revised list of mammals from this horizon has been given by Hooker (1987). Teeth and waterworn bones were also found in bed 13, the "Rolled bone bed" of Tawney and Keeping (1883).

Bivalve - Potamomya plana

Here is an example of some common fossils from just beneath the Crocodile Bed, probably from bed 15a. Potamomya plana (J. Sowerby) [or Erodona] is a low salinity, thin-shelled bivalve that commonly occurs with the pond-snail Viviparus in the Headon Hill Formation. Scattered amongst the shells are small black seeds, Brasenia ovula Brongniart, according to Edwards and Daley (1977). The small bivalve Potamomya plana ( which used to be known as Erodona plana) is common. There are some fish remains in this bed, particularly small fish vertebrae, now dark brown in colour. Brown fragments of turtle carapace are fairly common in the Headon Hill Formation. The Hampshire Crocodile, Diplocynodon hantoniensis is rare but of particular interest.

Fossil Erodona (Potomomya) shells, a type of Eocene freshwater bivalve, are abundant in the cliff of the Headon Hill Formation, between Milford-on-Sea westward to Taddiford Gap, and beyond, as seen here in the year 2020

[locator - ERODONA NEW]

More details on the Crocodile Bed are given in these extracts from Tawney and Keeping (1883) give their own observations and also refer to the fossil records of Barbara, Marchioness of Hastings. She lived at Efford, near Lymington, and her doctor owned Hordle Cliff.

"The description of the these deposits by the late Marchioness of Hastings contains the best information concerning the exact beds in which the vertebrate remains were found. We have collated the beds in the Marchioness's description with our own, and quote largely from her work, as it has never been translated into English. It is indeed fortunate that she has so carefully preserved the information for us relating to the beds which yielded the vertebrate remains.

The senior of the writers [presumably E.B. Tawney, Esq., M.A.] was then acting as her collector. He lived for a great part of his life close to Hordwell Cliff, and for four or five years worked regularly on the cliffs, collecting fossils for the Marchioness. Facts relating to the exact spots where the vertebrate and other remains were found were communicated to her, though occasionally she would assist with her presence. We are making this particular admission, because there are some statements in her description which the writer cannot reconcile with his memory or with the present state of the cliff... "

[Crododile Bed] "(15) At the top is soft sand with Paludina lenta [Viviparus lentus ], Limnaea caudata [Galba ], Cyrena arenaria [Corbicula?], Dreissena, Lepidosteus [fish] and Crocodile; then hard sand of pale or whitish tint with plates of Turtles, and bands of Potamomya plana; below are whity-brown sands, with carbonaceous layers and Potamomya in bands. The whole about 7 feet thick [2.1 m], may be called the Crocodile-bed, having been so known to local collectors; the best horizon for Crocodiles is about 5 feet (1.5m) up in this bed.

In the Marchioness's section it is No. 10, .. and seeds of Chara are mentioned. She also says that ... Potamides [a turreted gastropod] is found. In the Woodwardian Museum there is a Crocodilus Hastingsiae collected by one of us, with several specimens of Potamides pyrgota in the matrix among the bones. The Marchioness draws attention to this association. Of mammals, she mentions Paloplotherium, Dichobune, Hyaenodon, found in this bed [see modern works of Hooker on Eocene/Oligocene mammals of southern England]; of reptiles, besides the Crocodile, are [the turtles]Trionyx Henrici, T. Barbarae, T. marginatus, T. circumsulcatus and Emys crassus. Dr Wright states that Palaeotherium splenum, P. parvum, P. annectens, Microchaerus, and Spalacodon were also found in this bed. He does not state his authority. Searles Wood, in figuring Microchaerus does not state in which bed he found it."

[Beneath the Crocodile Bed] "(14) Greenish clay, 2 inches [ 5 cm] ; whity-brown sand, 6 inches [15 cm]; bluish grey clay-band, 1 inch [2.5 cm], with Melanopsis brevis.

[Rolled Bone Bed] (13) Light greyish-white sands 6 - 9 inches [15 - 23 cm]: a constant bed. It may be called the Rolled-bone bed, from the abraded state of the remains. Mammalian bones, Emys, Trionyx [turtles] and Crocodile are mentioned by the Marchioness. "

Owen (1861), after mentioning a gavial-like crocodile, from Bracklesham Bay commented: "In the Hordle beds have been found the C. Hastingsiae, with short and broad jaws; and also a true alligator (C. Hantoniensis). It is remarkable that forms of procoelian Crocodilia, now geographically restricted - the gavial to Asia, the alligator to America, and the true crocodiles to warm latitudes of Asia, Africa and America - should have been associated together, and represented by species which lived, during nearly the same geological period [Eocene], in rivers flowing over what now forms the south coast of England.

For an illustration of Diplocynodon, the genus in which the Hordle Cliff crocodile - Diplocynodon hantoniensis is now placed, see an example from London Clay of the Isle of Sheppey. The opening page of this excellent website, relevant in many respects to the Barton and Hordle webpages, is at Sheppey Fossils, Lower Eocene (Ypresian) fossils of the London Clay from the north coastal section of the Isle of Sheppey, Kent, UK. There is also a complete specimen of Diplocynodon figured from the Museum Victoria , Australia.

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Taddiford Gap continued

- Crocodile Bed - the Hampshire Alligator


Diplocynodon of Hordle Cliff was a type of alligator, rather than a typical crocodile, and it had an unusually long snout and peculiar teeth. In the upper jaw were two pairs of caniniform (canine-like) teeth, instead of one, according to Steel (1989) . They were in the fourth and fifth position. In the lower jaw there were three pairs of extra-large teeth (the first, third and fourth). Other genera of European alligators have the conventional upper-jaw sockets for the lower jaw teeth (unlike true crocodiles). Steel (1989) pointed out that Diplocynodon hantoniensis initially caused some confusion because the skulls have upper jaw knotches rather than complete sockets. This is why it became named as Crocodylus hastingsiae (the Marchioness of Hasting's crocodile, sometimes known as the Hampshire Crocodile). It was more correctly the "Hampshire Alligator" and lived amongst a type of Florida swamp-cypress tree (Taxodium ) which is also found at Hordle Cliff. The New Forest region was a Florida-type lagoon and cypress-swamp, warm enough for the alligators and with plenty of mammalian prey such as the horse-like Palaeotherium, bones of which can also be found in this cliff.

To consider the history, as given by Steel (1989) , Diplocynodon hantoniensis belongs to a genus that has been widespread in the Cenozoic from about 50 million years ago and lasted until only a few million years ago. This alligator lived in North America in the Middle Eocene but has not been found there is later strata. It may have originated in North America, an ancestral-type form Prodiplocynodon was living in Wyoming in the Late Cretaceous, before the extinction of the dinosaurs. It was a surviving reptile. In Europe Diplocynodon ranged from the Middle Eocene to the Middle Pliocene and occurs from Spain through southern England to Bulgaria. At Hordle Cliff (Upper Eocene) there is evidence of these alligators on the sandbanks near the margin of the lagoon. It is probable that Diplocynodon was the common British alligator for millions of years, but disappeared with cooling at the early signs of approach of the Pleistocene ice-age.

Not only are alligators much more restricted in distribution now, but so too are certain coniferous trees. Sequoia trees were the most abundant tree of Dartmoor in Oligocene times, yet the early sequoia ancestors seems to have evolved in the late Cretaceous in north-eastern Russia. Sequoia now lives naturally in the western USA and is not a native plant of Britain, but when planted in the New Forest (e.g. at Rhinefield) can grow large. Taxodium , the swamp-cypress is, noted above, a tree of Florida, but the fossil trunks of its relatives are in Hordle Cliff. The swamp-cypress, too, will also grow in Britain when planted in a favourable environment (e.g. the lake in Kew Gardens).

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Taddiford Gap continued
- The Limnean Limestone

The Limnean Limestone exposed in a landslide, just east of Taddiford Gap, Hordle Cliff, Hampshire, 2007

Details of a block of Limnean Limestone with Galba longiscata, from the Headon Hill Formation, Hordle Cliff, Hampshire

The Limnean Limestone is a thin limestone that was deposited in a freshwater lake. The main gastropod is Galba longiscata which was originally referred to here as "Limnea" or "Lymnea ". When the cliffs are not undergoing active erosion the bed may not be easily found. Renewned erosion just to the east of Taddiford Gap in 2007 has clearly revealed it.

Galba is a eurytopic [i.e. able to adapt to a wide range of environmental conditions; widely distributed], pulmonate [i.e. air-breathing], gastropod, that lives on water-weed in freshwater lakes. At the present day there is, for example, a lake in Turkey, Lake Sapanca in Marmara (Kosal Sahin and Yildrihim, 2007) , that has abundant Galba truncatula (formerly known as Lymnaea truncatula) and at about 40 degree North is about the correct latitude for Hordle Cliff in the late Eocene [now 51 degrees north because the equator has moved south since then]. This lake has water plants including Chara, which accords with the charophyte oogonia remains in the Limnean Limestone. It also has the common flat-coiled gastropod, Planorbis planorbis which can be compared to the Planorbina euomphalus of the the Limnean Limestone at Hordle Cliff. Of course Lake Sapanca is not a unique environment for comparison to the Hampshire Eocene lake. There are many other warm temperate lakes today that are similar. Lake Sapanca is rather high at about 30 metres above sea-level. The Hordle Cliff Lake was close to sea-level and very shallow.

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Hordle Cliff, near Taddiford Gap - Coast Erosion

Recent erosion of the cliff just to the east of Taddiford Gap, seen from the cliff top, Hordle Cliff, Hampshire, 26th June 2015


A view eastward of the site of recent erosion of the cliff east of Taddiford Gap, seen from the cliff top, Hordle Cliff, Hampshire, 26th June 2015


Steep, eroding cliff, above a narrow beach, east of Taddiford Gap, Hordle Cliff


An eroding part of the cliff  east of Taddiford Gap, with iron seeps from the Headon Hill Formation


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Hordle Cliff, sensu stricto, and Hordle Village

The main stretch of Hordle Cliff, sensu stricto extends for about one and half kilometres to the east of Taddiford Gap. The cliff takes its name from the former village of Hordle or Hordwell, which with its church, was in the situated on the cliff top. It is shown on Norden's map of 1595 and Cary's map of 1787. The village was destroyed by coast erosion in the early part of the 19th century. This was an actively eroding area and good for fossil collecting at the time of Marchioness of Hastings and the early geological work on the Headon Beds. This part is now inactive and largely vegetated. Erosion, however, is just commencing again (in 2007) at the western, Taddiford end.

An 1787 map of Christchurch Bay, Hampshire, showing the old village of Hordle, destroyed by the sea in 1820s

Here is a reference to the cliffs in 1757 and discusses Hordel-Cliff. However the details discussed mostly concern what is now known as the Barton Cliffs, which are further west, but at that time may not have had a separate name.

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.

Anonymous letter to Mr. S. Urban in the Gentlemans Magazine, vol. 27, 1757, pp. 64-65. It describes "Hordel-Cliff in the parish of Hampshire, .. situated on the sea coast between Lymington and Christchurch" but it is an account of the cliffs at Barton-on-Sea, a place which either did not exist then or was too small to be noted. The Barton cliffs at this time were just an uninhabited extension to the west of Hordle Cliff. This was of relative importance because of the existence of the original Hordle Village where there were houses and a church. Later, after coast erosion and destruction of the village, a new Hordle Village, the present one, was built well inland. The coastal church was demolished and a new church built at the new village.

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Eastern End of Hordle Cliff

Walking back, after fieldwork, near the eastern end of Hordle Cliff looking towards Milford-on-Sea and the Milford-Hordle car park

The eastern end of Hordle Cliff, with the lower end of the cliff, as seen from the cliff-top, looking east

Rabbits are common late in the day or at dusk at the bushy, overgrown, eastern end of Hordle Cliff

Cuspate and linear, beach shingle, features as seen from the cliff-top near the eastern end of Hordle Cliff


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Rook Cliff (east of Hordle Cliff)

Rook Cliff, Milford-on-Sea, view towards the ESE

Rook Cliff, Milford-on-Sea, gravel, brickearth and Headon clay in the cliff

Rook Cliff has some limited exposures of the Headon Hill Formation at the back of a gravel promenade and sea-defences. The upper part of this relatively low cliff is of Pleistocene gravel with brickearth. The descent of gravel terraces in steps can be seen. At the base of the exposed section is a blue-grey clay with abundant Viviparus pond-snail shells, occasional broken fragments of the freshwater clam 'Unio' and numerous, small, black seeds of the water-plant - Stratiotes. The vertical exposure is small and not as good as at the main Hordle Cliff section. Beneath this cliff-exposure is a gravel promenade with a concrete sea-wall. Blocks of Carboniferous Limestone have been placed here for protection and there are also groynes that may represent older sea-defences. The groynes are worn and damaged to some extent.

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For the coast just east of Hordle Cliff (embayment with shingle beach and beach huts) go to:

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END OF FIELD GUIDE - Or on to Adjacent Coasts? Milford-on-Sea, Erosion and Sea Defences

Go westward along the cliffs to the Barton and Highcliffe section?


Go eastward to the Hurst Spit?

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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.

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Please go to Highcliffe, Barton and Hordle Cliff - Bibliography and References .

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|Home and List of Webpages |Field Guides Introduction |Barton and Highcliffe |Barton and Highcliffe Coast Erosion and Sea Defences |Highcliffe, Barton and Hordle - Bibliography |New Forest Geology |Solent Estuaries | Hurst Spit | Milford-on-Sea

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


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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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Copyright © 2020 Ian 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.

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Dr Ian West, author of these webpages

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.