West, Ian. 2013. Barton and Highcliffe, Eocene Strata: Geology of the Wessex Coast of southern England. Internet site: www.southampton.ac.uk/~imw/barton.htm. By Ian West, Romsey and Southampton University. Version: 21st September 2013.
Barton and Highcliffe Geological Field Guide

Ian West,

Romsey, Hampshire
and Visiting Scientist at:
Faculty of Natural and Environmental Sciences,
Southampton University,

Webpage hosted by courtesy of iSolutions, Southampton University
Aerial photographs by courtesy of The Channel Coastal Observatory , National Oceanography Centre, Southampton.

This is the general geology webpage on the Barton-on-Sea cliffs, not the coast erosion webpage.


MORE BARTON AND HIGHCLIFFE!
See also associated webpages
Barton-on-Sea and Highcliffe - Geological Field Guide

Coast Erosion and Sea Defences at Barton-on-Sea and Highcliffe

Barton and Highcliffe - Erosion History

Highcliffe, Barton and Hordle - Bibliography

Hengistbury Head (Lower Barton Clay) and Mudeford Spit

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|Home and List of Webpages
|Field Guides Introduction. |Barton and Highcliffe - Coast Erosion - General |Barton and Highcliffe - History of Coast Erosion at Barton |Hordle Cliff and Milford-on-Sea |Hurst Spit |Highcliffe, Barton and Hordle - Bibliography |New Forest Geology | Hengistbury Head |Solent Estuaries |Brownsea Island, in Poole Harbour |Bournemouth Cliffs

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(You can download this educational site to SurfOffline, WebCopier or similar software to keep a safe permanent offline copy, but note that at present there is periodic updating of the live version.)

Septarian nodules from the base of Bed C of the Barton Clay being eroded out at the foot of the cliffs at Naish Farm, near Highcliffe during a storm in October 2006

A rain squall over the western part of the Isle of Wight seen from Barton-on-Sea, Hampshire, November 2009

Finding sharks' teeth washed out of the Barton Clay between Highcliffe and Barton-on-Sea, Hampshire, 24 November 2007

Stratiolamia macrota a common fossil shark's tooth of the Eocene Barton Clay at Barton-on-Sea, Highcliffe and Hengistbury Head, Hampshire and Dorset, southern England

Tooth of the Eagle Ray - Myliobatis, washed out of the Barton Clay and found on the beach between Highcliffe and Barton-on-Sea, Hampshire

An old photograph of the cliffs at Barton-on-Sea, Hampshire, in the 1950s or early 1960s before sea defences were constructed

Clifs at Barton-on-Sea, Hampshire, looking westward, in the 1950s before there were any major sea defences

Barton Clay, Highcliffe, 07.03.01

Barton Clay, Highcliffe, 07.03.01

Barton Sand with Chama Bed

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LOCATION -

Barton-on-Sea, Hampshire

See Barton-on-Sea location on zoomable Bing aerial photographs and maps. See also Google Earth.

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INTRODUCTION:

Safety

Soft mud, Highcliffe, 07.03.01

The main hazard at Highcliffe, Barton and Hordle Cliff is of sinking into soft mud, particularly on the clay terraces above the beach level. In wet conditions it is wise to stay on the beach and collect from the lowest part of the cliffs. On the few Highcliffe and Barton coast sections with steep cliffs there is a small risk of being struck by a falling rock, pebble or lump of mud. Safety helmets might be needed where such risk exists. Landslides are common in the area. Generally these do not move fast and are more of a hazard to property than to people. However, care should be taken. Adders live on these cliffs but bites are very rare. It is hazardous to stand on the cliff-top of gravel close to the edge. At some places there is a hazardous overhang.

Individual geological visitors and field leaders should make their own risk assessment and no liability is accepted.

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INTRODUCTION:

Geology of Barton and Highcliffe - Maps and Locations

See also the Barton and Highcliffe Coast Erosion and Sea Defences webpage.

Location sketch map of the Barton and Highcliffe Coast, Hampshire

Old geological map of Hengistbury Head and Mudeford Spit, near Bournemouth, Dorset, revised to 1891

Barton, Highcliffe and Hordle cliff section

Locations at Barton-on-Sea, Hampshire - Hoskin's Gap, 2007

Locations in the  Barton-on-Sea area, Hampshire, - the Chewton Bunny, Highcliffe Car Park

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STRATIGRAPHY:

Introduction

A chart showing lithostratigraphic schemes for the Palaeogene strata of the Bournemouth and Poole area, including Brownsea Island and Barton-on-Sea

The sequence of Eocene strata at Hengistbury Head, Dorset, with comparison and correlation to the Boscombe Sands and Barton Clay section at Friars Cliff and Highcliffe

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INTRODUCTION-STRATA:

Barton and Highcliffe Strata - General Introduction

Sea erosion of the foot of cliff of Barton Clay at Naish Farm, Highcliffe, Hampshire, 30 September 2006

The Barton Clay, the Barton Sand and the overlying Headon Hill Formation (of the Solent Group) form part of the well-known Hampshire Basin, and are exposed at Barton and Highcliffe in Christchurch Bay, and also at Alum Bay and Whitecliff Bay, in the Isle of Wight. The strata are of the Bartonian and Priabonian Stages of the Upper Eocene Series. In terms of age in years these strata were deposited between about 42.1 amd 35.4 million years (Harland et al., 1982). They correspond roughly in age with the famous Eocene gypsum deposits of Paris (from whence comes the name - Plaster of Paris).

The type-section of the Barton Clay and Barton Sand at Barton Cliffs on the mainland consists of sandy clays in the lower part , dark sandy clays and stiff drab clays in the middle part, and clayey sands and light-coloured sands in the upper part (29.26m). The total was given as 61.56m by Burton (1929) but Barton (1973) has more recently considered the Barton Clay to be thicker (46.4m) and given a total figure for the Barton Beds of 75.4m (note that Bristow, Freshney and Penn (1991) gave the range of the Barton Clay thickness in the Bournemouth area as 20 - 60m, less than this figure but probably based on Burton).

Most of the strata are very fossiliferous. The Barton Clay has yielded more than 500 species of fossil mollusc shells. These are quite robust and can easily be cleaned by simply washing them with a soft brush. They look much like modern subtropical shells but have lost their colour. The shell, though, is still of the original aragonite and only the organic matter has been lost. They range from minute corals (Turbinolia) and the little, prickly gastropod Typhis pungens to the robust and fairly common gastropod - Clavilithes macrospira to the rare fan-shell Hippochrenes amplus . The turreted gastropods Turritella imbricateria and Turritella sulcifera are very common, and sharks teeth and ray-fish teeth (see above) can be found from time to time. Both the sea-defences and the retreat of the coast away from the most fossiliferous strata has much reduced the fossil-collecting potential. Nevertheless good specimens can still be found in the Naish Farm area between Barton and Highcliffe, and the cliffs at the back of the beach here are well-worth a visit.

Not much of the Barton Clay can be seen from Barton eastward to the end of the Marine Drive East. The cliffs have large blocks of limestone at the base, some timber piles, much gravel spread above and some iron sheet-piling here and there. The engineering works also require roads or tracks for vehicles and machines. This central section is instructive with regard to the development of landslides, the use of and failure of sea-defences. It is also a good area to see the Pleistocene gravel at the top of the cliff and the yellow, oxidised Barton Sands or Becton Sand Formation. Apart from geologists it is of interest to geography students, environmental science students and civil engineering students. A visit is recommended.

East of Barton natural cliffs and good exposures start again near Becton Bunny. Longshore drift is from west to east because of the prevailing southwesterly winds. Much protective beach debris cannot get eastward past the Barton sea-defences, which are designed to hold it, so here there is terminal scour and enhanced coast erosion. This enables the Barton Sands or Becton Sand Formation to be seen in quite good exposures. There are some shells, of which the most robust is the white and conspicuous bivalve Chama squamosa of the Chama Bed. Above this horizon the bivalves and gastropods are thin-shelled, being of sheltered lagoonal or estuarine origin. The shells are not as strong or as abundant as in the Barton Clay.

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STRATIGRAPHY

Succession of Strata

Pleistocene  
Brickearth
Plateau Gravel
0 - 2.1m
1.5 - 7.6m.
Eocene
 
 
 
Solent Group, Headon Hill Fm. (lower part only)
Becton & Chama Sand Fms. (Barton Sand)
Barton Clay Formation
Bracklesham Group, Boscombe Sands ("Mudeford Sands" or "Highcliffe Sands" at Friars Cliff)
 
29m.
46.4m.
>12m.

Thicknesses are from Barton (1973). The Plateau Gravel of Pleistocene age lies unconformably on the Barton Clay and Barton Sand (Chama Sand and Becton Sand). The Brickearth at the top of the gravel is a periglacial silt deposit, light brown in colour.

Barton-on-Sea, Hampshire

Above is the key diagram of the Eocene sequence here (click or double-click to enlarge!). To study the Highcliffe, Barton and Hordle Cliff sections successfully the field geologist should as far as possible commit this sequence to memory, keeping a paper copy at hand to remind him or her of the details. This is because parts of the section are obscured by sea defences and much is slumped in the cliffs or is overgrown with vegetation.

As is always the case when dealing with cliff sections look first for conspicuous markers and work from those. The basal pebble bed which lies above a sandstone cliff - Friars Cliff is obvious. The basal clay of the Barton Clay can be seen, with the approximate position of the Nummulites prestwichianus bed (although in poor condition now). A1 and A2 are not properly exposed now because of sea defences at Highcliffe. A3 might be seen at the western base of the Naish Farm section, depending on coast erosion and extent of slumping of the cliffs. Bed C, the Voluta suspensa is very obvious and occupies much of the lower cliff between Naish Farm and the first Barton sea defences. It cannot be missed because of the septarian nodules above and below, and also the pale, bored bed in the centre. D, E and F are now seen in limited slumped exposures in the cliff, often of difficult access (because of risk of sinking in). Exposures of G, the Stone Band (or Shell Bed) are not as common as in the past but might be seen here and there in the Barton landslides. The Chama Bed can often be seen at the foot of the cliff at the eastern end of the Barton Sea Defences, near Becton Bunny. Beyond the the Barton Sands or Becton Sand succession is quite clear and easily studied near Becton Bunny. The Lignite Beds, L, are two conspicuous black bands seen in Beacon Cliff. The Headon Hill Formation is fairly well exposed in Beacon Cliff and Hordle Cliff and for further information on this see the Hordle Cliff webpage.

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STRATA

Clay Mineralogy

Introduction

Clay mineral distributions in the Hampshire Basin, based on the work of Gilkes (1968), with some further palaeoenvironmental interpretation

Diagram summarising the clay mineralogy of the Barton Clay, Barton Sand and Headon Hill Formation from Highcliffe to Milford-on-Sea, Hampshire, redrawn with modifications after Professor Bale (1984)

Summary of Clay Mineral Abundances

The following notes are based on the excellent, detailed work of "Tunde" Bale (1984) which summarises the clay mineralogy of the Barton Formation. Much more detail is given and the interested reader should consult the original thesis (available for reference in the National Oceanography Library, the National Oceanography Centre, Southampton).

The clay mineralogy of the Upper Eocene succession of the Hampshire Basin essentially comprises illite which is greater or equal to smectite. In turn smectite is greater or equal to kaolinite (the coarser and non-expandible clay mineral). This is more abundant than the mixed-layer, illite-smectite. Chlorite is common but in quantitative terms is minor compared with the other clay minerals. This assemblage is similar to that observed by Gilkes (1966), who did the pioneering work on the Hampshire Basin clay mineralogy. A major advance of the Bale work is the recognition of the mixed-layered phases, which he identified and estimated semi-quantitatively.

Dioctahedral smectite and illite dominate. Together, these two phases generally account for about 70% of the clay fractions. Illite occurs in higher amounts than smectite in the non-marine 'Lower Headon Beds', whilst approximately equal amounts of illite and smectite occur in the marine Barton Clay and Barton Sand Formations. Some horizons however. possess considerable higher smectite contents. These notably include the marine sequence at Whitecliff Bay and the lower parts of the Barton Sand at Barton. Kaolinite and illite-smectite occur in lesser amounts of around 8-20%. Chlorite occurs only as a minor constituent in a limited number of the marine sediments, and the lignitic clays. In addition, some smectites with chlorite interlayers occur in some of the lignitic clays and limestones, with abundant carbonaceous matter. Deviations from the above occur in the succession at Alum Bay. At this locality the smectite, illite-smectite and chlorite are absent or occur in very low amounts in the clay fractions of the pebble bed and the Barton Sand. The depletions are of high significance in the palaeosol at the top of the Barton Sand and the succeeding lower parts of the Headon Hill Formation at Hatherwood Point, near Alum Bay, Isle of Wight. The depletion of these phases is accompanied by a substantial increase in the amounts of kaolinite and/or illite. This peculiar clay mineralogy at Alum Bay is thought to be due to localised differential derivation of detritus and/or the imprint of surficial (acid soil pedogenesis) processes. These are discussed elsewhere

Discussion of the Clay Mineralogy

The discussion of the clay mineralogy of the Upper Eocene sediments is centred on three factors that generally dictate the assemblage and relative abundance of clay minerals in sedimentary rocks. These are the nature of the source; contemporaneous neoformations and/or alterations; and sedimentological factors such as 'differential settling'. Diagenetic transformations are not considered important because of the shallow burial (~ 200m depth) history of the Upper Eocene succession under study. The clay assemblage of the sediments and those of other Palaeogene sediments in southern England were then employed for deducing the palaeo-environmental conditions and presenting a new view of the derivation of the clay assemblage.

Derivation of the Clay Assemblage

i) Constancy of Source

The general constancy of the illite-smectite-kaolinite-illite/ smectite assemblage in the Upper Eocene sediments suggests constancy of sources of detritus. A similar deduction of constancy of source was made by Blondeau and Pomerol (1968) from a study of heavy mineral assemblages in the sediments. With illite and smectite dominating in the clay fractions, the clays belong to the 'eastern province' assemblage of Gi1kes (1966, 1967). This, Gi1kes believed, was derived mainly from rocks exposed to the north and east of the Hampshire Basin. This hypothesis is broadly acceptable. However, recent advances in the geology of southern England necessitate re-assessing and updating views on the clay derivation.

(to be continued)

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STRATA:

Lower Barton Clay - Introduction

At Friars Cliff, to the west of the main Barton Clay section and between Highcliffe and Mudeford there is a good exposure of the base of the Barton Clay with the Boscombe Sands beneath. The sands here have, in the past, been regarded as younger than the strata at Hengistbury Head and have received various names, including the Highcliffe Sands. They are now regarded as the equivalent of the Boscombe Sands at Hengistbury Head and have the same conspicuous pebble bed above and not far above that the prestwichianus Bed (with Nummulites prestwichianus). See Bristow, Freshney and Penn (1991), the Bournemouth Memoir, for further details.

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STRATA:

Lower Barton Clay - Description

See also the Barton and Highcliffe Coast Erosion and Sea Defences webpage.

A sign of coastal retreat - loss of beach material at Naish Farm, Highcliffe, Hampshire, revealing an erosional platform of Lower Barton, A2 grey-green clay, with fallen septarian nodules lying loose above

Lower Barton Clay exposed at low spring tide at Naish Farm, Highcliffe

Septaria washed out the Barton Clay at the scoured locality just east of Chewton Bunny, Barton-on-Sea, Hampshire

Rather less than half of the Barton Clay belongs to the "Lower Barton Beds". Various authors, following Prestwich (1849), have taken the base of a pebble bed to be the base of the Barton Clay. It seems sensible to take what is probably a transgressive pebble bed as the base and that method is used here. Note, however, that Keeping (1887) and Curry et al. (1978) used the bottom of the Nummulites prestwichianus Bed, a little higher, as the base. This nummulite bed consists of green, glauconitic sandy clay. Most of the Lower Barton Beds which follow are rather sandy and they include the so-called Highcliff Sands of Gardner, Keeping and Monckton (1888) (not to be confused with the conspicuous sands of Bracklesham age at Friars Cliff). White (1917) summarised these beds. He stated that they take in a set of loamy sands with Voluta athleta (Sol.) and Cassis ambigua (Sol.) (now known as Volutocorbis ambigua (Solander)), and ends with rusty sand containing abundant Pholadomya margaritacea J. Sowerby. Unfortunately, with degradation of the cliff and with the construction of sea-defences little can be seen of these fossil beds now. The Lower Barton succession was said to be the richest in species of molluscs, with a large proportion resembling living forms from Australia and Japan, and seeming to indicate a considerable depth of water (White, 1917). Small corals (Turbinoliae), echinoderms (Ohphiura wetherelli Forbes, etc), claws of crabs, teeth of fish (Arius, Myliobatis, etc.), turtle bones, a few worn freshwater shells, and drift wood, are among other fossil remains present in these beds. For a full list see Burton (1933).

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STRATIGRAPHY:

Middle Barton Beds - Barton Clay

See also the Naish Farm Section, as described in the Barton and Highcliffe Coast Erosion and Sea Defences webpage.

The Voluta suspensa Bed or Bed C of the Middle Barton, in a cliff section in the Naish Farm area, east of Highcliffe

Horizontal landslide movement at the D shear surface, seen in the D scarp, between Naish Farm and Sea Road Access, Barton-on-Sea, Hampshire, 2006

The bioturbated or burrowed band in the centre of Bed C of the Barton Clay, at the eastern end of the Naish Farm area, Hampshire

The Middle Barton Beds includes the part of the Barton Clay still visible in the cliffs in spite of sea-defences. It is seen from Chewton Bunny at Highcliffe eastward to Barton-on-Sea, with the best section at Naish Farm just east of Highcliffe. The Barton Clay of the Middle Barton Beds is more truely argillaceous than the Lower Barton. The large, spectacular fossil shells of the Barton Beds have mostly come from these clays, although it is less easy now to find such specimens than in the past. Sharks teeth are present here (as in the Lower Barton). This sequence has septarian nodules of argillaceous limestone, usually with some sand and some glauconite. The lowest two layers are of rounded nodules, but only the one at the top of Bed C, the Voluta suspensa Bed, is well exposed at present. Two upper bands of nodules were originally visible, but now the upper part of the cliff is either badly slumped or covered with sea-defences, so that only one is easily found. Near the upper nodule horizons are exceptionally-rich fossil beds (Bed E - the Earthy Bed). The top of the Barton Clay is marked by the Stone Band or Shell Band, probably a storm accumulation of shells or some type of shell beach. This is brown and sideritic. It is not always firmly lithified, but often is, producing reddish, hardened slabs, which can be found on the beaches. These reddish slabs are full of Turritella and various bivalves. The Barton Clay of the Middle Barton has yielded remains of a rare cetacean - Basilosaurus , formerly referred to as Zeuglodon wanklyni Seeley, some bones of which together with a fine collection of Barton molluscs are in the building of the Bournemouth Natural Science Society (White, 1917).

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LOCATION

Naish Farm, Highcliffe - Barton Clay Exposure

Barton Clay, Highcliffe, 07.03.01

This photograph shows the base of the cliffs with fossiliferous Barton Clay, east of Highcliffe and below Naish Farm at about map reference SZ224931. The view is westward across the mouth of Chewton Bunny to a grassy hill at Highcliffe in the mist. On the top of the cliff here is a large car park which is reached by driving south at a sign "to the sea" from the centre of the main shopping street of Highcliffe. There are toilets at the car park.

A large groyne with blocks of Portland Stone (from the Isle of Purbeck) projects from the coast at Chewton Bunny. Longshore drift is from west to east because of the prevailing south-westerly winds. On much of the south coast of England groynes are able to bank up sand on the west side and cut off the supply of beach material to the east. This common phenomenon is known as "terminal scour" and where it happens local enhanced erosion and even the formation of embayments may take place. Here there is a retreating clay cliff and a sandy beach. Although much of the Barton and Highcliffe coast has lost its natural appearance and been turned into a defended embankment, this stretch remains relatively natural and is conserved as such largely for geological purposes. At one time the whole coastline here was like this and justifiably famous for fossil collecting. Good fossils can still be found in the clay and are occasionally washed out on the shore.

The lower cliff is eroded by the sea at high tide and particularly during storms. Part of it, like the projecting bulge here, consists of landslipped debris and part is of clay in situ. The best fossils tend to be found in the clay in place, although shells and occasionally vertebrate remains can also be found in the moved clay debris.

Barton Clay, Highcliffe, 07.03.01

Here is a representative part of the cliff in the Naish Farm stretch (on 07.03.01). Most of the cliff consists of the dark grey Barton Clay, but at the top are a few metres of Plateau Gravel of Pleistocene age. This is the remains of a periglacial river terrace, that we will consider further later. The light brown gravel is to some extent slumping over the clay. You can see two terraces of Barton Clay with liquid mud flowing over the brink from the upper one. The mud is supplied with water that runs out from the porous and permeable gravel at the top. The combination of steepening of the cliff by the sea and the supply of water from above results in many small landslides. Incidently, the clay is "steaming" because the morning sun is just beginning to warm the wet, dark, heat-absorbing surface.

Coastal retreat of the Barton Clay cliffs has averaged about a metre per annum, but may be locally higher in the Naish Farm area, because of the effects of sea defences to the west. The low cliff formed by erosion of the lowest terrace is, just here, mostly of landslipped debris and is not good for fossil collecting. On the beach there are numerous septarian nodules washed out of the clay, as shown above. The sea floor offshore consists of numerous, residual septarian nodules of this type.

A little further east there is an undisturbed cliff and by comparision with the cliff diagram provided in this website the position can be fixed. Bed C is easily recognised because it between two septarian bands and with a thin, burrowed, light-grey marl in its central part.

Gun emplacement and Barton Clay, Highcliffe, 07.03.01

The view is to the east, towards Barton on Sea, although it was not clearly visible because of mist when the photograph was taken. A terrace that was higher has descended to the beach now. Much of the clay here is in place, but there is some slumping, and some small channels of water and mud that descend to the beach. Notice the septarian nodules two-thirds way up the cliff in the left part of the photograph. These mark the top of bed C. This is a good place for collecting fossils, mostly because the clay is in situ . The tilted gun emplacement largely now buried under the beach sand. I knew this years ago when it was against the cliff, and still just about possible to get into. The gun emplacement was a cliff-top defence against invasion by Germany constructed in about 1940 in the Second World War. Accurate determination of the distance of this from the present cliff top would gove a measure of the extent of coastal retreat just here. See one at Abbotsbury on the Chesil Beach, and notice how the erosion there has been much less. The beach was photographed at low tide and consists largely of sand but much gravel. The sand has probably mostly come partly from sand within the Pleistocene gravel but also from much sand dispersed within the Barton Clay. Dark green glauconite grains in the beach sand demonstrate the Tertiary origin of much of it. The gravel is brown and subangular and has come from the Plateau Gravel. Only the clay is not accounted for. This is washed out to sea and in stormy conditions the muddy nature of the seawater is clearly seen.

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STRATIGRAPHY continued:

Becton Sand Formation or Barton Sands

Barton Sand, east of Barton

The Barton Sands or Becton Sand comprises about 27 to 30m of light-coloured, fine-grained sands, with some loamy and clayey beds, particularly at the base and near the top. These sands can be seen clearly in the photographs taken at the eastern end of the Barton sea defences. Because beach sediment can no longer easily reach here from the west (longshore drift is from west to east), being arrested by the sea-defences, erosion is intense. This is a site of "Last Groyne Syndrome", with cliffs to some extent purposely sacrificed by holding back shingle to protect the cliff-top properties of Barton-on-Sea. The increased erosion here yields excellent exposures of the Barton Sand or Becton Sand. The junction with the Barton Clay, marked by the Turritella-rich and iron-rich Shell Bed or Stone Band, is not exposed at present here, however, and it is the upper part of the Chama Bed which is first seen, unprotected, on the shore.

The section continues eastward to the small oblique valley of Becton Bunny. The Headon Hill Formation of clays with some minor siderite and limestone and many "freshwater" fossils follows and is well exposed at Beacon Cliff, Taddiford (Long Mead End) and beyond in Hordle Cliff and towards Hurst Spit.

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STRATIGRAPHY continued:

The Chama Bed - Bed H

Barton Sand with Chama Bed

The blue-grey, argillaceous sand of the Chama Bed in a mid-cliff landslide, at Sea Road Access, Barton-on-Sea, Hampshire, 22nd November 2009

Chama Bed

Chama Bed, close

Chama squamosa

The Chama Bed, immediately above the Barton Clay, is a shelly, bluish-grey, sandy clay passing up into clayey sand. Chama incidently is pronounced "Kay-ma" because of the Greek origin of the name according to the late Professor Dennis Curry. The characteristic bivalve Chama squamosa Solander is abundant (squamous, incidently, means scaley, which well describes the appearance of this bivalve). It is sometimes found with paired valves, but, in general, as shown in the photographs, it is present in a death assemblage, a thanatocoenose. Probably there has been little distant transport of these shells, but movement by storms of the argillaceous shoal-sand in which they lived. Chama is a genus ranging from probably Upper Cretaceous to Recent. It is an epifaunal suspension feeder and usually attached. The modern Chama, larger and more spiny than these specimens, is known as a "Jewell Box" and occurs on reefs in Indo-Pacific tropical waters. I do not know whether the Barton Chama was attached, and if so, what to. The palaeolatitude was not tropical; it was about 37 degrees north, about the same as southern Spain, but a little wetter with no significant evaporites (not north of Paris). The temperature was higher than normal in the Eocene, though, so the presence of these tropical shells is not surprising. I wonder if they had some reddish or violet colour to them, like the modern ones.

A interesting aspect of the shells is the extent to which many have been bored by marine organisms. The shells are certainly thick enough to contain many borings, but it is not clear just why the borings are such features here because they are not particularly abundant elsewhere in the Barton strata.

The Chama Bed is now extensively covered by sea-defences of limestone blocks and gravel, further west but it is a notorious bed for quicksands, water running through the Barton Sands and emerging in this poorly lithified basal unit. Most of the quicksands in the cliff are now covered, but it is still a problem to horse riders in the New Forest, forming small but treacherous, yellow boggy springs on Yew Tree Heath and elsewhere in the eastern Forest. Oxidation of pyrite within it produces chalybeate (iron) springs both in the cliffs and in the New Forest. Notice the "rusting" along a crack in one photograph and the iron-cementation of some flint shingle from the beach on the face of the exposure in another. At Calshot, in the power station outfall tunnel, it is an oyster bed rather than a typical Chama Bed. The blue-green colour of the Chama bed is mostly the result of a content of much glauconite amongst the sand, but there is some variation in appearance according to the extent of oxidation and the proportion of clay present.

Burton (1929; 1933) has discussed the general characteristics and fauna of the Chama Bed. At Barton it is 5.5m (18 feet) thick. The lower part, 3m (10 feet), consists of bluish-grey sandy clay with numerous fossils. The upper part, 2.4m (8 feet), consists of greenish grey or bluish grey, clayey sand with fewer fossils, chiefly bivalves. It is this upper part which is shown here in the photographs, and has relatively few shells apart from Chama. If you look carefully, though, you will notice part of a Turritella. Of all the subdivisions of the Barton Beds, it is the lower part of the Chama Bed which has most foraminifera. Bryozoa are more numerous in this bed than in the Barton Clay beneath. An interesting feature of the Chama Bed, not normally seen now, is the presence of spheroidal concretions from 0.3m to almost a metre in diameter.

Burton (1933) pointed out that molluscs do not occur as thin seams of shells, as in the lower beds, but are distributed throughout the vertical extent of the bed. They can be lost through decalcification. This is seen in the top of the present exposure of the bed, where there are only moulds, and there has been decalcification where the bed is high in the cliff, west of Barton Court. The lower part is characterised by Chama squamosa and Lyria decora and the upper part by 'Meretrix' incurvata and Volutolithes pertusus. The fauna embodies a number of species not occurring in the lower subdivisions at Barton. Common Lower Barton species, absent in the Middle Barton, but reappearing in the Chama Bed are: Calliostoma nodulosum and Tornatellaea simulata . For more information on the fauna see Burton's (1933) faunal list for Bed H in his section VII. The bed is also exposed at Alum Bay and Whitecliff Bay; it is of broadly similar thickness and is very fossiliferous at both localities (White, 1921)

The Chama Bed can be regarded as a marker of a significant local change in enviroment about 40 million years ago. According to Murray and Wright (1974) the Barton Clay beneath is of shelf regime until the Chama Bed indicates marked shoaling. There was a silting-up of the sea, heralding the lagoonal and freshwater conditions of the Headon Hill Formation which were to follow in a while.

Above the Chama Bed come the Becton Bunny Beds; these are light-coloured unfossiliferous sands overlain by "earthy" sands. There follows dark sandy clay with the brackish water bivalve - Oliva branderi J. Sowerby. Next there is sandy loam with brackish water shells such as Cyrena, Dreissensia, Erodona etc. (White, 1917). Finally the white and yellow sands of the Long Mead End Beds contain Lucina gibbosula Lam., Batillaria pleurotomoides Lam. etc and are terminated by a thin band of greenish clay at the junction with the Headon Hill Formation ("Headon Beds" in the old literature). The Barton Sands shows evidence of shoaling water conditions and a progressive change towards the lagoonal and lacustrine environments of the Headon Hill Formation.

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STRATIGRAPHY continued:

Becton Sand Formation - Bed I

A view from the cliff edge of the last groyne syndrome at the eastern end of the Barton-on-Sea sea defences, with Becton Bunny and Hordle Cliff beyond, Hampshire, 4th March 2013

Bed I, a soft sandstone bed of the Becton Sand Formation, east of Barton-on-Sea and near Becton Bunny, Hampshire, 4th March 2013

Next follows 7.9m (26 feet) of grey, yellow and white sand. It consists of greyish, micaceous sands in which the grains are held together by fine argillaceous natter. Below Barton Court parts of it are vivid yellow in colour, but it seems paler at a low level near the beach. It has been described as unfossiliferous, but moulds of shells occur in the upper part (Burton,1929;1933). A photograph above shows the unit after the unusually heavy rain of the winter 2012 to 2013. Grey clay derived from water above the Becton Bunny Bed (J) has run down the cliff. The Becton Bunny Bed itself is not conspicuous because of fallen sand from the Long Mead End Bed (K).

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. STRATIGRAPHY continued

Becton Bunny Bed or the Olivella branderi Bed - Bed J

[The bed with the dwarf Olive Shells]

Becton Sands etc west of Becton Bunny, Sept 2002, cliff-top view

Fallen blocks of clay with shells from the Becton Bunny Bed, Becton Sand Formation, near Becton Bunny, east of Barton-on-Sea, Hampshire, 4th October 2013

Becton Sands with Becton Bunny Bed, west of Becton Bunny, Barton

There is good access to the Becton Sands, with fallen material from the Becton Bunny Bed. It descends to the beach a short distance further east.

The Becton Bunny Bed above the white sand of Bed I, at the mouth of Becton Bunny, east of Barton-on-Sea, Hampshire, March 2013

This is at the mouth of Becton Bunny. It probably was once called Beacon Bunny (or Bourne) and took its name from the adjacent Beacon Cliff, to the east, where there was a fire-beacon. The valley is narrow and oblique to the coast, so that with coast erosion the mouth would appear to moved westward. The Becton Bunny Bed is accessible here and clear of debris but, however, near the valley it may be weathered and not necessarily contain well-preserved shells. It may be worth checking the cliffs on the far side (eastern) of the valley. Fossils are common in the clay and if not found in situ they will easily be found in fallen blocks.

The gastropod, Olivella branderi, in Bed J, the Becton Bunny Bed, east of Barton-on-Sea, Hampshire, 2013

This grey argillaceous unit is well-seen in the photographs. It is 7.9m (26 feet) thick. Drab grey sandy clay forms the lowest 1.8m (6 feet), followed by 6m (20 feet) of greenish grey sandy clay, with much ferruginous matter near the surface. This causes it to weather to a pinkish drab colour. At about 3m (10 feet) from the base there are small spheroidal ferruginous concretions, averaging only about 10 cm (4 inches) in diameter (Burton,1929; 1933). Marine to brackish fossils are numerous but fragile and difficult to collect. The distinctive gastropod Olivella branderi is abundant, but also occurs in the bed above. Olivella branderi (J. Sowerby) has a superficially close resemblance to the Purple Dwarf Olive, Olivella biplicata Sowerby of the western coast of North America. It about the same size, and, as you can see in the photograph, there are traces preserved of similar colour marking. Olive shells occur in various parts of the world today but are mostly Indo-Pacific, tropical forms. Most of them are larger than this "olive" (although the Twisted Plait Olive, Olivancillaria contortuplicata Reeve of the Carribean to Patagonia is also a small form. For more information on olive shells see Dance (1992).

A related species of Olivella is found living today in sandy shallow subtidal and low intertidal sediments of the eastern Pacific coast of the USA. It usually lives partially buried and feeds on detrital material. Often, large numbers of shells are washed onto sandy beaches of the west coast of the Pacific northwestern United States. The olive shells in the Becton Bunny Bed seem to be more or less in place and not accumulated as shell banks, (see reference: Marine Biology - soft shore.).

Nautilus has been found but Turritella does not occur so high in the Barton sequence.

A brief summary of the main fauna is as follows:
Olivella branderi (Marine gastropod) - very abundant.
Nucula (marine bivalve)
Pitar (marine bivalve, a Venus clam, Veneridae)
Potamides (estuarine turreted gastopod)
Corbicula (estuarine bivalve)
Bayania (estuarine gastropod)
Nautilus (marine cephalopod)
Callianassa, a mud-shrimp, occurs in soft concretions.

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Becton Sand - Oxidation of Pyrite

Jarosite - the Yellow Sulphate

Jarosite on the surface of fallen debris, Becton Sand, near Becton Bunny, east of Barton-on-Sea, Hampshire, 4th October 2013

Jarosite is a conspicuous yellow mineral, occurring as encrustations in places where oxidation of pyrite has taken place. It is an hydrated iron sulphate with potassium, sodium or ammonium. It is not true alum because it does not contain aluminium in any significant quantity. However, where it is present there is abundant pyrite and the theoretical potential for manufacturing alum. Associated with it may be the green ferrous sulphate - melanterite, known as copperas, but that is less common. These Becton Sand cliffs may show melanterite in addition to the conpicuous jarosite. Brownsea Island is the most notable historic site for copperas production, but Alum Chine, Bournemouth is another well-known location. Alum Bay, Isle of Wight also takes its name from pyrite and copperas production.

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LOCATIONS - EASTERN COAST - HIGHCLIFFE TO MUDEFORD



LOCATIONS:

Highcliffe to Mudeford

View eastward from Friars Cliff, Highcliffe towards the Holm Oak covered cliffs of Lower Barton Clay and on to the landslipping cliffs of Middle Barton Clay at Naish Farm and beyond to Barton-on-Sea

Exposures of the Lower Barton Clay are poor near Highcliffe Castle because of build-up of the beach and rampant growth of the Holm Oak or Evergreen Oak, Quercus ilex, over the cliffs

Highcliffe Castle on the cliff top above the Lower Barton Clay section and just to east of Friars Cliff, Highcliffe, Dorset

The cliffs near Highcliffe Castle were once subject to rapid erosion of the type that now takes place at the Naish Farm Section (in the Barton and Highcliffe Coast Erosion and Sea Defences webpage).

. Numerous small fossil and fish otoliths have been found in these cliffs in the beds A1 and A2 of the Lower Barton Clay. Now the beach has built up, just westward of the rock armour groynes of the Highcliffe sea defences. The sea rarely has much access to the cliffs now and the exposures are very poor. However, if you walk a few hundred metres further west to Friars Cliff then there is a good section of the Boscombe Sands overlain by the Lower Barton Clay. This is shown in the photographs which follow.

This section of coast between the main car park at Highcliffe and the end of the cliffs westward near Mudeford exposes the Upper Eocene, Lower Barton Beds underlain by the top of the Middle Eocene, Bracklesham strata. It is not as well exposed as previously. An interesting cliff of sand is visible in the western part but much of the eastern part of this stretch is now obscured by sea-defences and vegetation.

Comments on the previous state of the cliffs here were made by Wrigley (p. 173) in Burton (1931) and by the late fossil collector and violinist, Mr St. John Burton himself.
"Mr Wrigley remarked that the changes in the Run and in the egress of the rivers had been either the effect or the cause of alterations in the local direction of tidal force, so that active coast erosion had been transferred eastward to Milford and Hordle, leaving the cliff at Highcliff in a stable condition with accumulations of blown sand - to the chagrin of the present generation of fossil collectors who rarely were able to examine the riches of the Lower Barton Beds."
"The author [Burton] expressed his thanks to previous speakers. In the course of his own observations extending over a period of many years along this part of the Hampshire coast, he been impressed by the results of erosion eastward of Chewton Bunny at Highcliff and also below Barton Court. At the latter locality, the cliff had been cut back 25 yards [23m] in that number of years, which incidendently meant the loss of the most fossiliferous beds at this point. Temporarily increased activity of marine erosion here did not, however, necessarily correspond with the more important changes in the position of the Run. Under some conditions, the river-current flowed in a kind of fleet, extending for about a mile beyond Cliff End, and at half tide the surf broke on a submerged sandbank, formed between the 'fleet' and the open sea."

Dewatering structures in the Boscombe Sands of Friars Cliff, Highcliffe, Dorset

Dewatering ball and pillar structures in the Boscombe Sands, Friars Cliff, Highcliffe, Dorset, 2007

Dewatering ball and pillar structures in the Boscombe Sands, Friars Cliff, Highcliffe, Dorset as seen in 2005.

An interesting aspect of the sands as shown in the photographs is the presence of dewatering structures.

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BARTON FOSSILS



FOSSILS:

Barton Clay and Becton Sand Fossils

Shark's tooth, from beach, Highcliffe, 07.03.01

Shark's tooth, Highcliffe, 07.03.01

Fossil shell, Highcliffe, 07.03.01

Fossil shell, Athleta, Barton Clay, Highcliffe, 07.03.01

Barton Fossil

Barton and Bracklesham Fossils

Some selected fossil bivalves from the Barton Clay Formation, two species of which occur at Hengistbury Head, in addition to occurrence at Barton and Highcliffe

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Barton Fossils of the Dent Collection

Bournemouth Natural Science Society of 39 Christchurch Road, Bournemouth, Dorset, BH1 3NS (telephone 01202-394534) has a large collection of fossils from the nearby coast of Barton and Highcliffe. The following notes are from Sir Daniel Morris in 1914:

"An important event in the history of the society has been the acquisition of the Dent Collection of Barton fossils. This collection was brought together many years ago by the late Mr. Dent of Barton Court, and his father who were owners of the cliffs. Good facilities were then afforded for collecting Barton fossils; but owing to the fall and washing away of these cliffs these facilities have long ceased to exist. Living close by, Mr. Dent and his father were successful in bringing together a collection which has long been regarded as of special value. It was described by Mr. Henry Keeping, curator of the museum at Cambridge, as 'one of the best in the world - probably only equalled by the Edwards Collection in the British Museum and the one in the Sedgwick Museum at Cambridge.' Before the collection was purchased it was carefully examined in behalf of the society by an expert from the British Museum, who reported: 'All the fossils are in a fine state of preservation, and such a series will probably never be obtained again'. There are 800 specimens of vertebrate animals and 3,375 fossil shells. Some of the latter are of exceptional interest. There are several specimens of the rarer species showing variations; also the gradual changes in development from the young to the adult stage. Of some species there are more than 100 specimens.
Perhaps the most interesting fossils in the Dent Collection, amongst the vertebrates, are the bones of an extinct whale-like animal - the Basilosaurus formerly referred to as Zeuglodon (but this is a junior synonym). Such remains are said to be uncommon in museum collections in this country. The British Museum possesses [in 1914] no portions of this animal from the Barton beds."

The present writer, can certainly confirm the quality of this collection. I have seen it recently, but remember the initial impression back in my school-days given by the fine Clavilithes longaevus and the fan-shell Hippochrenes amplus, amongst many others.

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BARTON FOSSILS

Burton's Listing - Introduction.

See the classic papers by St.John Burton (1925; 1929; 1931 and 1933). Mr. St.John (pronounced "Syngen") Burton, lived in a bungalow on the cliff top at Barton-on-Sea and collected regularly in a very systematic way from the various divisions of the Barton Clay Formation and Becton Sand Formation (then the "Barton Sand"). [I only met him once and that was in the 1950s at Bournemouth Natural Science Society]. He had divided the sequence of the Barton Clay into a series of lettered beds, A to F, and the Barton Sand into horizons G (the Shell Bed or Stone Band) up to L. There have been some later terminological changes with regard to the Becton Sand, but his units are easily understood. The divisions of the Barton Clay are not overall so easily recognised now (except for certain parts, such as Horizon C and D) because of the combination of sea defences, rock armour, artificially-deposited gravel and, as always, frequent landslides. The "Horizons" of Burton and other aspects of the Barton cliffs are discussed elsewhere in this webpage and in associated webpages on coast erosion and landslides at Barton and Highcliffe:
Barton and Highcliffe - Coast Erosion and Landslides.
Barton Erosion History

Burton, E. St.J. 1933. Faunal horizons of the Barton Beds of Hampshire. Proceedings of the Geologist's Association, vol. 44, Part 2, pp 131-167. This classic paper on the fossils of Barton-on-Sea with a large and important faunal list. Since the paper was published in 1933, some of the faunal names have changed, but the old names are usually easily recognised. A version of the list is reproduced below.

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.


LIST OF BARTON FOSSILS - by E. St. John Burton, 1933

This is a simplified version of the 1933 list of fossils known from the Barton Clay Formation and the Becton Sand Formation ("Barton Sand"). It is complete copy of Burton's list as a sequence of names. At the time when it was made the Barton Clay cliffs were very much better exposed and more favourable for collecting. Now parts are much obscured by sea-defences and some of these fossils will be difficult or impossible to find. The species names are given in their original form and the genera have not been updated. The original charts given in Burton's paper should be consulted, though, if bed by bed information is needed. This is not given here. He listed the frequency of occurrence of each of these species within the Barton units A1, A2, B, C, etc up to Bed K in the Becton Sands. He stated whether the species was "Very Common, Common, Frequent, Not Common, Rare, Very Rare or not found. It would be too time-consuming the retype this data in the version of the list below. The reason that the species list has reproduced here in text format is that it is now searchable by computer. Regard this list as only an introduction and if feasible do follow up new fossil data from current literature.

[NB. These fossils are from the Barton Clay and Barton Sand of the Barton-on-Sea and Highcliffe cliffs, and not from equivalent strata (i.e. Lower Barton) at Hengistbury Head. For Hengistbury fossils see my webpage:
Hengistbury Head Geology.]




PLANTAE (List of St. John Burton, 1933)

[This list is very limited regarding plants. See the later work of Chandler (1960) for more information on this subject.]

Endocarp (allied to Mastixia (rare in A3 only)
Pityostrobus dixoni (Bowerbank)
Sequoia sp. [tree, new at that date to the Bartonian of England]
Wood fragments and rhizomes.

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FORAMINIFERA (List of St. John Burton, 1933)

Anomalina ammonoides (Reuss)
Anomalina grosserugosa (Gumbel)
Cornuspira carinata (da Costa)
Cornuspira involvens Reuss
Cristellaria cultrata Montfort
Cristellaria inornata d'Orbigny
Cristellaria rotulata Lamarck
Miliolina ferussaci (d'Orbigny)
Miliolina seminulum (Linne)
Nebecularia sp.
Nodosaria badenensis d'Orbigny
Nummulites elegans J. de C. Sowerby
Polymorphina acuminata (d'Orbigny)
Pullenia sphaeroides (d'Orbigny)
Ramulina sp.
Truncatulina lobatula (Walker and Jacob)
Truncatulina refulgens Monfort

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HYDROZOA (List of St. John Burton, 1933)

Axopora michelini Duncan
Holaraea parisiensis (Michelin)

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ANTHOZOA (List of St. John Burton, 1933)

Graphularia wetherelli Milne-Edwards
Madrepora solanderi Defrance
Oculina cf. conferta Edwards and Haime
Paracyathus crassus Edwards and Haime
Turbinolia affinis Duncan
Turbinolia bowerbanki Edwards and Haime
Turbinolia firma Edwards and Haime
Turbinolia forbesi Duncan
Turbinolia frediciana Edwards and Haime
Turbinolia humilis Edwards and Haime
Turbinolia sp. nov.

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ECHINODERMATA (List of St. John Burton, 1933)

Cidaris websteriana Forbes
"Echinus" dixoni Forbes
Echinopedina edwardsi (Forbes)
Hemiaster branderi Forbes
Maretia grigonensis (Desmaret) (= Spatangus omalii Forbes
Ohioglypha sp.

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BRYOZOA (POLYZOA) (List of St. John Burton, 1933)

?Aimulosia spp.
Biselenaria offa Gregory
Conopeum buski (Gregory)
Conopeum crassomurale (Gregory)
Conopeum sp.
Heterocella sp.
?Hippoporina sp.
Hornera sp.
Lichenopora gregoryi Canu
Lunulites transiens Gregory
Membranipora sp. nov.
Micropora cribiformis Gregory
Mucronella augustooecium Gregory
Nellia sp.
Onychocella sp. nov.
Peristomella sp. nov.
Puellina sp.
Pyripora sp.
Srupocellaria sp.
Sphaeropora [Heteropora] glandiformis (Gregory)
Sphaeropora [Heteropora] glandiformis (Gregory) variety
Teichopora (Bracebridgia) clavata Gregory
Tryposta sp.
Umbonella bartonensis Gregory

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BRACHIOPODA (List of St. John Burton, 1933)

Terebratula sp. nov

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ANNELIDA (List of St. John Burton, 1933)

Ditrupa plana J. Sowerby
Serpula crassa J. de C. Sowerby
Serpula cf. exigua J. de C. Sowerby
Serpula extensa Solander
Serpula cf. flagelliformis J. de C. Sowerby
Serpula heptagona J. de C. Sowerby

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CRUSTACEA (List of St. John Burton, 1933)

(Ostracoda)

Bairdia contracta Jones
Cythere consobrina Jones
Cythere costellata (Romer)
Cythere plicatula Munster
Cythere scrobiculoplicatula Jones
Cythere striatopunctata Jones
Cythere wetherelli Jones
Cythereis horrescens Jones
Cytherella muensteri (Romer)
Cytheridea debilis Jones
Cytheridea muelleri (Munster)
Cytheridea perforata (Romer)
Krithe bartonensis (Jones)

(Cirripedia)

Balanus unguiformis J. de C. Sowerby var erisma Darwin

(Malacostraca)

Callapa sp.

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MOLLUSCA - BIVALVIA)(List of St. John Burton, 1933)

Amussium corneum (J. Sowerby)
Anadara globulosa (Deshayes)
Anomia tenuistriata Deshayes
Anomia sp
Arca biangula Lamarck
Barbatia appendicalata (J. Sowerby)
Bicorbula gallica (Lamarck)
Bicorbula sp. nov
Callista aff. laevigata (Lamarck)
Callista suberycinoides (Deshayes)
Callista transversa (J. de C. Sowerby)
Callocardia aff nitidula (Lamarck)
Chama squamosa Solander
Chama turgidula Lamarck
Chama sp.
Chlamys carinata (J. de C. Sowerby)
Chlamys recondita (Solander)
Chlamys tumescens (Edwards MS)
Clavagella coronatum Deshayes
Corbula cf costata (J. de C. Sowerby)
Corbula cuspidata J. Sowerby
Corbula ficus (Solander)
Corbula globosa J. Sowerby
Corbula cf. lamarcki Deshayes
Corbula pisum J. Sowerby
Corbula rugosa Lamarck
Crassatellites bronni (Merian MS)
Crassatellites grignonensis (Deshayes)
Crassatellites var anglica S.V. Wood
Crassatellites pumilio S.V. Wood
Crassatellites subquadratus (S.V. Wood)
Crassatellites sulcatus (Solander)
Crassatellites sulcatus var ensiformis (Edwards MS) S.V. Wood
Crassatellites tenuisulcatus (Edwards MS)
Cultellus affinis (J. de C. Sowerby; S.V. Wood)
Cyrena gibbulosa Morris
Cyrena deperdita Deshayes
Divaricella colvellensis (Edwards MS)
Divaricella rigaultiana (Deshayes)
Fossularca lissa (Bayan) (= F. laevigata Caillat non Spengler)
Gari compressa (J. de C. Sowerby)
Gari rudis (Lamarck)
Gastrochaena ampullaria (Lamarck)
Glycimeris deleta (Solander)
Glycimeris proxima (S.V. Wood)
"Leda" minima (J. Sowerby)
Lentidium nitidum (J. Sowerby)
Lima cf. sorar S.V. Wood
Limopsis scalaris J. de C. Sowerby
Lithodomus sp.
Loxocardium obliquum (Lamarck)
Lucina cf concentrica Lamarck
Lucina (Cavilucina) elegans Defrance
Lucina (Gibbolucina) gibbosula Lamarck
Lucina spinulosa Edwards
Lutetia parisiensis (Deshayes)
Mactra compressa Deshayes
Martesia spp.
"Meretrix" gravida (Edwards MS)
Meretrix incurva (Edwards)
Meretrix trigonula (Deshayes)
Modiola cf. dimidiata S.V. Wood
Modiolaria seminuda (Deshayes)
Mytilus affinis J. de C. Sowerby
Mytilus strigillatus S.V. Wood
Nemocardium parile (Deshayes)
Nucula ampla S.V. Wood
Nucula bisulcata J. de C. Sowerby
Nucula praelonga (Edwards MS)(S.V. Wood)
Nucula similis J. Sowerby
Nucula tumescens (Edwards MS) S.V. Wood
Ostrea dorsata Deshayes
Ostrea plicata (Solander)
Ostrea gigantea J. Sowerby
Ostrea cf. tenera J. Sowerby
Panopea corrugata J. Sowerby
Pholadomya margaritacea J. Sowerby
Pitaria sp.
Pteria [Avicula] media J. de C. Sowerby
"Solen" sp.
Sportella sp.
Sunetta branderi (Edwards MS)
[bottom of page 154]
"Tellina" ambigua J. de C. Sowerby
Tellina filosa J. de C. Sowerby
Tellina hantoniensis Edwards
Tellina (Eoelliptica) tellinella Lamarck
Tellina sp.
Terodo sp.
Tivelina elegans (Lamarck)
Tivelina solandri (J. Sowerby)
Trachycardium porulosum (Solander)
Trinacria deltoidea (Lamarck)
Venericardia corpuluscum S.V. Wood
Venericardia cf. crebisulcata (Edwards M.S.) (S.V. Wood)
Venericardia davidsoni (Deshayes)
Venericardia oblonga J. Sowerby
Venericardia simplex (S.V. Wood)
Venericardia sulcata (Solander)
Venericardia trapezoidalis (S.V. Wood)
Veniella pectinifera (J. de C. Sowerby)
Woodia crenulata (Deshayes)

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SCAPHOPODA(List of St. John Burton, 1933)

Dentalium (Laevidentalium) acicular Deshayes
Dentalium striatum Sowerby

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GASTROPODA (List of St. John Burton, 1933)

Acera striatella (Lamarck)
Acteon cf. gardneri Cossman
Acteon sp.
Acteon sp.
Acteonida elongata (J. de C. Sowerby)
Adeorbis politus (Edwards M.S.) Morlet
Adeorbis sp.
Adeorbis sp.
Admete (Bonellitia) evulsa (Solander)
Admete (Bonellitia) evulsa var. producta (Edwards M.S.)
Admete (Bonellitia) nitens (Beyrich)
Admete (Comptostoma) quadrata (J. Sowerby)
Ampullela mutabilis (Solander)
Ampullela cf. parisiensis (d'Orbigny)
Ancilla aveniformis J. Sowerby
Ancilla buccinoides Lamarck
Ancilla (Tortoliva) canalifera Lamarck
Ancilla dubia (Deshayes)
Ancilla obesa Edwards M.S.
Aporrhais c.f. sowerbyi (Mantell)
Asthenotoma biconus (Edwards)
Asthenotoma conoides (Solander)
Asthenotoma dissimilis (Edwards)
Asthenotoma helicoides (Edwards)
Asthenotoma microcheila (Edwards)
Asthenotoma pupa (Edwards)
Asthenotoma zonulata (Edwards)
Bartonia caniculata (J. de C. Sowerby)
Bathytoma aff. granata (J. de C. Sowerby)
Bathytoma hemileia (Edwards)
Bathytoma turbida (Solander)
Batillaria cf. calcitrapoides (Lamarck)
Batillaria pleurotomoides (Lamarck)
Bayania hordacea (Lamarck)
Bela juncea (Solander)
Bittium semigranulosum (Lamarck)
Bittium terebrale (Lamarck)
Bornsonia lineata Edwards
Bornsonia semicostata Edwards
Bullinella acuminata (J. Sowerby)
Bullinella angystoma (Deshayes)
Bullinella constricta (J. de C. Sowerby)
Bullinella elliptica (J. de C. Sowerby_
Bullinella sp.
Calliostoma nodulosum (Solander)
Calyptraea aperta (Solander)
Cappulus penatus (Lamarck)
Capulus squamaeformis (Lamarck)
"Cassidaria" nodosa (Solander)
Cerithioderma costellatum (Edwards M.S.)
"Cerithium" sp.
Clavatula desmia (Edwards)
Clavilithes cylindricus Wrigley
Clavilithes elongatus (Edwards M.S.) Wrigley
Clavilithes longaevus Solander
Clavilithes macrospira Cossman
Clavilithes scalaris (Lamarck(
Clavilithes sp. indet.
Cominella deserta (Solander)
Cominella sp.
Conomitra parva (J. de C. Sowerby)
Conomitra parva var pumila (J. de C. Sowerby)
Conomitra porrecta (Edwards)
Conorbis alatus (Edwards)
Conorbis dormitor (Solander)
Conus (Hemiconus) lineatus Solander
Conus (Hemiconus) scrabriculatus Solander
Cornulina minax (Solander)
Cryptoconus priscus (Solander)
Cryptospira pusilla (Edwards)
Crypstospira simplex (Edwards)
Cypraea (Bernaya) bartonensis Edwards
Dientomochilus bartonensis (J. Sowerby)
Drillia bracheia (Edwards)
Drillia coarctata (Edwards)
Drillia constricta (Edwards)
Drillia gomphoidea (Edwards)
Drillia granulata (Lamarck)
Drillia innexa (Solander)
Drillia scrabiuscula (Edwards)
Drillia verticillum (Edwards)
Drillia sp. indet.
Eopleurotoma cedilla (Edwards)
Europleurotoma lima (Edwards)
Europleurotoma monerma (Exwards)
Europleurotoma puella (Edwards)
Europleurotoma rotella (Edwards)
"Epitonium" acutum (J. Sowerby)
Epitonium interruptum (J. de C. Sowerby)
Epitonium reticulum (Solander)
Epitonium cf, sculptatum (Deshayes)
Epitonium undosum (J. de Sowerby)
Epitonium sp.
Eulima deshayesi (Cossman)
Eulima macrostoma (Charlesworth M.S.)
Eulima polygyra (Charlesworth M.S.)
Eulima sorocula Edwards M.S.
Eulima sp.
Euthriofusus carinella (J. Sowerby)
Euthriofusus lima (J. de C. Sowerby)
Euthriofusus regularis (J. Sowerby)
Euthriofusus sp. nov.
Faunus rigidus (Solander)
Ficus greenwoodi (J. de C. Sowerby)
Ficus nexilis (Solander)
Ficus sindonata Wrigley
Fusinus acuminatus (J. de C. Sowerby)
Fusinus asper (J. de C. Sowerby)
Fusinus porrectus (Solander)
Globularia grossa (Deshayes)
Globularia patella (Lamarck)
Globularia sigaretina (Lamarck)
Globularia sphaerica (Deshayes)
Hemipleurotoma aspera (Edwards)
Hemipleurotoma callifera (Edwards)
Hemipleurotoma denticula (Basterot)
Hemipleurotoma denticula var. conulus Edwards
Hemipleurotoma denticula var. mutica Edwards
Hemipleurotoma gentilis (Edwards)
Hemipleurotoma reticulosa (Edwards)
Hemipleurotoma varians (Edwards)
Hippochrenes amplus (Solander)
Homalaxis sp.
Lacuna sp.
Lyria costata (Solander)
Lyria decorata (Beyrich) (= Voluta maga Edwards)
Marginella bifodo-plicata (Charlesworth)
Marginella gracilis Edwards
Mathildia bourdoti de Boury
Melanopsis cf. fusiformis J. Sowerby
Melanopsis cf. subfusiformis Morris
"Mitra" marginata Lamarck
Mitra (Mitreola) scabra (J. de C. Sowerby)
"Mitra" volutiformis Edwards
Murex albionis Wrigley
Murex bispinosus J. de C. Sowerby
Murex defossus (Pilkington)
Murex defossus var. lineata (Edwards M.S.)
Murex frondosus Lamarck
Murex tricarinatus Lamarck (= Murex asper Solander)
Murex tripteroides Lamarck
"Nassa" obtusa Edwards M.S.
Nassa caillati Deshayes
Nassa epiglottina Lamarck
Nassa sp.
Nassa (Ampullonatica) ambulacrum (J. Sowerby)
Nassa (Polinices) hantoniensis (Pilkington)
Nassa (Euspira) labellata Lamarck
Obeliscus canaliculatus Edwards M.S.
Obeliscus excavatus Edwards M.S.
Obeliscus c.f. polygyrus Edwards M.S.
Odostomia aligata Lamarck
Odostomia hordeola Lamarck
Odostomia sp.
Olivella branderi (J. Sowerby)
Olivella salisburiana (J. Sowerby)
Orthochetus sp. nov. aff. charlesworthi
Paludestrina sp.
Pirena vulcanica (Schlotheim)
Pollia (Tritonidea)lavata (Solander)
Potamides cf. variabilis (Deshayes)
Potamides vagus (Solander)
Pseudoneptunea sindonata (Edwards M.S.)
Ptychatractus interruptus (Pilkington)
Pyrazus angulatus (Solander)
?Rhaphitoma acuticosta (Nyst)
Rhaphitoma plicata (Lamarck)
Rimella rimosa (Solander)
Ringicula parva (Charlesworth MS.) R.B. Newton
Rissoa (Alvania) bartonensis (Charlesworth MS.)
Rissoa (Alvania) globulus Edwards MS.
Rissoa nana (Lamarck)
Rissoa sp.
Rissoina raincourti Cossman
Rostellaria excelsa Giebel
Roxania aff. coronata (Lamarck)
Sassia arguta (Solander)
Sassia flandrica (de Koninck)
Sassia websteri Wrigley
Scaphander sp.
Semicassis ambigua (Solander)
Seraphs fusiformis (Lamarck)
Seraphs sopitus (Solander)
Serpulorbis cancellatus Deshayes
Sinum clathratum (Gmelin)
Solariaxis caniculatus (Lamarck)
Solarium plicatum (Lamarck)
Strebloceras cornuoides Carpenter
Strepsidua turgida (Solander)
Stylifer cf. inserta Edwards MS.
Suessionia [Phos] coartata (Edwards)
Surcula crassicostata (Edwards)
Surcula extorta (Solander)
Surcula aff. inarata (J. de C. Sowerby)
Surcula laevigata (Edwards)
Surcula laneolata (Edwards)
Surcula macilenta (Solander)
Surcula microdonta (Edwards)
Surcula rostrata (Solander) var. antiqua Edwards
Surculites errans (Solander)
Sveltella microstoma (Charlesworth MS.) R.B. Newton
Sycostoma bulbeforme (Lamarck)
Sycostoma bulbus (Solander)
Sycostoma pyrus (Solander) [very common in D and G]
Teinostoma dubium (Lamarck)
Terebra cf. plicatula
Theodoxis sp.
Theodoxis sp.
Theodoxis sp.
Tornatellaea simulata (Solander)
Trivia platystoma Edwards
Turbo sulcata (Pilkington)
Turbonilla costata (J. Sowerby)
Turbonilla costellata Edwards MS.
Turbonilla pulchra Deshayes
Turbonilla cf. scalaroides Deshayes
Turritella edita (Solander)
Turritella imbricateria Lamarck [very common in E]
Turritella sp.
Turritella sp.
Turritella sp.
Typhis parisiensis d'Orbigny (= T. fistulosis J. Sowerby non Brocchi
Typhis pungens Solander
Uxia elongata (Nyst)
Uxia nassaeformis (S.V. Wood MS.) Wrigley
Volutilithes pertusus Swainson [= Voluta humerosa Edwards]
Volutocorbis scabriculus (Solander)
Volutospina ambigua (Solander) [very common in A3 and E]
Volutospina ambigua var.flexicostata (Edwards MS.)
Volutospina athleta (Solander) [Athleta (Volutospina) athleta (Solander) - common in B]
Volutospina athleta var. brevi-spina (Edwards MS.)
Volutospina athleta brevi-spina fortis Edwards
Volutospina depauperata (J. de C. Sowerby)
Volutospina lucta rix (Solander) [very common in E][this is the large Athleta (Volutospina) luctator (Solander), a well-known Barton fossil]
Volutospina lucta rix var. bi-spina
Volutospina nodosa (J. de C. Sowerby)
Volutospina scalaris (J. de C. Sowerby)
Volutospina solandri (Edwards)
Volutospina suspensa (Solander)
Volutospina sp.
Volvaria acutiuscula J. Sowerby
Volvulella lanceolata (J. de C. Sowerby)
Xenophora agglutinans (Lamarck) [small conical shell, very common in E]
Xenophora discoidea (J. Sowerby)
[end of list of gastropods]

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CEPHALOPODA (List of St. John Burton, 1933)

Belosepia sepiodea (Blainville) [distribution not known]
Nautilus sp. indet [occurs in places, not common to rare]
[end of list of cephalopods]

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VERTEBRATA - PISCES [fish] (List of St. John Burton, 1933)

Aetobatis sp.
Apriodon woodwardi
Arius egertoni (Dixon)
Carcharodon auriculatus Blainville [shark, very rare]
Cybium bartonense A. S. Woodward [rare]
Cylindracanthus rectus Egerton
Edaphodon? leptognathus Agassiz
Eugaleus minor Agassiz
? Galeocerdo sp.
Lamna obliqua (Agassiz) [syn Otodus obliquus - shark's tooth]
Lamna vincenti (Winkler)
Lepidosteus sp.
Mioliobatis dixoni Agassiz [frequent - Myliobatis - ray fish teeth]
Mioliobatis tolicapicus Agassiz [Myliobatis]
Mioliobatis sp. indet.
Notidanus primigenius Agassiz
Odontaspis acutissima (Agassiz)
Odontaspis cuspidata (Agassiz)
Odontaspis macrota (Agassiz) [Frequent - a usual Barton shark's tooth]
Odontaspis trigonalis (Jackel)

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(PISCES - FISH CONTINUED - OTOLITHS - Otolithus)
[The reporting by St. John Burton of 37 species of otoliths (ear-stones of fishes) is based on a large series of specimens collected by Rev. W.H. Webster, B.A. of Barton-on-Sea. See the extensive later work on Barton otoliths by Fred Stinton:
Stinton, F. 1974 to 1980. Fish Otoliths from the English Eocene, Palaeontographical Society.]

Otolithus (Apogonidarum) bouryi Priem [presumably an otolith - ear stone of a fish]
Otolithus bouryi duplex Shepherd
Otolithus (Arius) crassus Koken
Otolithus (Arius) sp.B, E.T. Newton
Otolithus (Arius) sp.C, E.T. Newton
Otolithus (Arius) cf. danicus Koken
Otolithus (Arius) parvus Schubert
Otolithus (Berycidarum) bartonensis Schubert
Otolithus (Brotulidarium) rzehaki Schubert
Otolithus (Cepola) praerubescens Schubert
Otolithus (Clupeidarum) cf. testis Koken
Otolithus (Dentax) nobilis Koken
Otolithus (Dentax) aff. subnobilis Schubert
Otolithus (Elops) sp.
Otolithus (Gadus) praeluscus Shepherd
Otolithus (Macrurus) aff. gracilis Schubert
Otolithus (Merluccius)shephardi Schubert
Otolithus (Monocetris) lemoinei Priem
Otolithus (Ophidiidarum) cf. acutangula Koken
Otolithus (Ophidiidarum) dimidiatus Schubert
Otolithus (Ophidiidarum) sp.
Otolithus (Ophidiidarum) subregularis Schubert
Otolithus (Ophidiidarum) waltoni Schubert
Otolithus (Ophidium) pantanelli Basoli
Otolithus [----] sp. nov.
Otolithus Percidarium aff. plebeius Koken
Otolithus (Phycis) bartonensis Schubert
Otolithus (Platessa) sector Koken
Otolithus (Pleuronectidarum) accuminatus Koken
Ottolithus (Psetta) praemaximus Shepherd
Otolithus (Sciaenidarum) insignis Koken
Otolithus (Serranus) bartonensis Priem
Otolithus (Serranus) concavus Priem
Otolithus (Solea) approximatus Koken
Otolithus (Sparidarum) gregarius Koken
Otolithus (Trachinus) mutabilis Koken
Otolithus (insertae sedis) umbonatus Koken [otolith]

[end of otolith section - continues with more sharks and ray fish etc.]

Physodon secundus Winkler [Physodon is a shark belonging to the Carcharidiidae, - Carcharias. The genus is known from the Eocene of the United Kingdom, the United States and Namibia.]
Pristis bisulcatus Agassiz [sawfish]
Scyliorhinus minutissimus (Winkler) [small tooth of shark?]
Squatina cf. crassus Daimeries
Triodon cf. antiquus Leriche
Tubercles of a ray-fish
Vertebrae of fish

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REPTILEA (List of St. John Burton, 1933)

? Argochelys sp.

Crocodilus [Is this the specimen at Bournemouth Nat. Sci. Society? Compare to the well-kown, Hordle Cliff alligator (or "Hampshire Crocodile"), Headon Hill Formation, Diplocynodon hantoniensis . (I have no information as to whether it is the same.)]

Palaeophis [very rare in A3] [a marine snake also known from the Lower Eocene]

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MAMMALIA (List of St. John Burton, 1933)

Zeuglodon wanklyni Seeley
[Basilosaurus? Vertebrae of this marine mammal or whale, still appear from time to time in the cliff of Barton Clay a short distance east of Chewton Bunny, Highcliffe. It was first named on the basis of a skull found in the Barton Clay cliffs in 1876.]

[end of original list]






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PLEISTOCENE STRATA




STRATIGRAPHY

Pleistocene Gravel

Pleistocene gravel on Barton Sand

East of Barton Court, at the top of the cliffs there are good sections of Pleistocene, subangular, flint gravel lying unconformably on Eocene Barton Sand (Becton Sand Formation). At the location shown here, a few hundred metres east of Barton Court, a gravel terrace at about 30m height gives way eastward to a somewhat lower terrace. The periglacial river gravels contain much iron in ferric condition and this gives them their characteristic brown colour. Humic acids from decomposing vegetation in a podzol soil profile transports iron downwards in the relatively humid climate of southern England. The iron can be redeposited lower an iron-pan, and an example is shown here. These iron pans are not continuous for any great distance but in certain cases they are impervious enouth to hold up water. The Barton Sands beneath have been much oxidised and turned a more yellow colour than in the lower cliffs where eroded by the sea. Water goes through both the gravel and the underlying sand here and flows out at the base of the Barton Sands. This has been a major cause of landslipping in the past, and explains why landslides can sometimes be on a larger scale at Barton compared to Highcliffe.

Sedimentary structures in the gravels include shallow channels and some thin beds of sand. Cryoturbation structures from the freezing and thawing of the ground during periglacial conditions occur in places. Palaeolithic implements have been found here.

The brickearth above is a brown silt resembling loess. It has been claimed that in some places in southern England this is indeed of wind-blown origin. It may, however, in this area be largely river silt. Similar brickearth in the Hill Head area of Southampton Water has a clay mineral composition related to that of Chalk, but probably in that case there has been much solifluction from the Chalk of Portsdown Hill. The clay mineralogy of this brickearth in the Barton Cliffs has not been studied, but there is no nearby source of Chalk. Of course, the gravels beneath consist of the insoluble material, the flint, from the Chalk of the northern and western fringes of the Hampshire Basin, together with some Tertiary material. Exactly what was the origin of the brickearth is less obvious. Probably most has come ultimately from Tertiary clastic deposits with clay contributions from the Tertiary and Chalk and probably also with abraded flint debris (this is a suitable subject for a student project).

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STRATIGRAPHY - PLEISTOCENE continued:

Brickearth

Brickearth above Pleistocene fluvial gravel in a slipped block near the cliff top, east of Naish Farm, Barton-on-Sea, Hampshire

At the top of the cliff, over the gravel, is one to two metres of brickearth. This is a brown Pleistocene silt deposit, generally without visible stratification (there is one conspicuous parting in this area where the brickearth is very thick - 2 metres). It has been regarded by many as a loess deposit of wind-blown dust in cold conditions. Others have attributed it to solifluction. Near Salisbury a brickearth deposit has been found to contain the remains of lemmings which have been entombed in their burrows. It is of course possible that solifluction of a loess could occur.

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Returning from the Cliffs

Waterfall beneath the bridge, up Chewton Bunny, Highcliffe, Dorset, after dark, January 2010

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Offshore:

Christchurch Bay

Palaeovalleys of Velegrakis et al. 1999 in Poole and Christchurch Bays

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ADJACENT AREAS

For more on coast erosion and sea defences at Barton and Highcliffe see:

Barton and Highcliffe Coast Erosion Webpage.

Go west to:

Hengistbury Head and Mudeford Spit?

Go east to:

Hordle Cliff and Milford-on-Sea?

or

Hurst Spit?

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ACKNOWLEDGEMENTS

I am very grateful to the late Paul Clasby for some very useful comments and corrections. Caroline Clasby and other students have assisted in the field. I thank Dr Ken Collins and Sarah Snowden for discussing septarian nodules in the field and the offshore distribution of Barton Clay horizons.

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BIBLIOGRAPHY AND REFERENCES

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

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




This is the general geology webpage on the Barton-on-Sea cliffs, not the coast erosion webpage.


MORE BARTON AND HIGHCLIFFE!
See also associated webpages
Barton-on-Sea and Highcliffe - Geological Field Guide

Coast Erosion and Sea Defences at Barton-on-Sea and Highcliffe

Barton and Highcliffe - Erosion History

Highcliffe, Barton and Hordle - Bibliography

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Copyright © 2013. Ian West, Catherine West, Tonya West and Joanna Bentley. All rights reserved. This is a purely academic website and images and text may not be copied for publication or for use on other webpages or for any commercial activity. A reasonable number of images and some text may be used for non-commercial academic purposes, including field trip handouts, lectures, student projects, dissertations etc, providing source is acknowledged.

Disclaimer: Geological fieldwork involves some level of risk, which can be reduced by knowledge, experience and appropriate safety precautions. Persons undertaking field work should assess the risk, as far as possible, in accordance with weather, conditions on the day and the type of persons involved. In providing field guides on the Internet no person is advised here to undertake geological field work in any way that might involve them in unreasonable risk from cliffs, ledges, rocks, sea or other causes. Not all places need be visited and the descriptions and photographs here can be used as an alternative to visiting. Individuals and leaders should take appropriate safety precautions, and in bad conditions be prepared to 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.

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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.


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