West, Ian and Chen, Yining. 2017. Beaulieu River Estuary, Hampshire: Geological Field Description. Internet site: wessexcoastgeology.soton.ac.uk/Beaulieu-River-Estuary.htm. By Ian West and Yining Chen. Part of Geology of the Wessex Coast. New Version: University, 15th October, 2017. (Associated with the Lepe Beach website). By Dr. Ian West, Romsey, and Professor Yining Chen, now in China.


Beaulieu Estuary - Geological Field Description, part of Geology of the Wessex Coast .

A view of an incised and flooded meander of the Beaulieu River estuary, Hampshire, from Bucklers Hard, 2008

Index and List of Webpages

|Solent - Lepe Beach and Stone Point Website

|Solent Geology - Introduction |Solent Geology Bibliography - General, Undivided |Solent Geology Bibliography - Topics, Alphabetically. |Lymington and Keyhaven coast and saltmarshes. |Calshot Spit and Stanswood Bay. |Solent - Chilling Cliff, Brownwich Cliff and Hill Head | Hurst Spit |Geology of Fawley Power Station |Geology of the New Forest

Selected external links:
Beaulieu: National Motor Museum, Palace House & Beaulieu Abbey | Exbury Gardens and Steam Railway | The New Forest National Park

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.

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INTRODUCTION

General

See also the related webpage regarding Lepe Beach:

LEPE BEACH AND STONE POINT

For more detail on the Solent area, the reader may wish to consult the important publication of the Channel Coastal Observatory, NOC, Southampton:

Cope , S.N., Bradbury, A.P. and Gorcyzynska, M. 2008. Solent Dynamic Coast Project: Main Report. January 2008. Channel Coastal Observatory, National Oceanography Centre, Southampton. Available online as a large pdf file. The main descriptive text and diagrams run to about 185 pages, and this is most useful to people seeking information on the Solent. There are many more pages of questionnaire sheets, intended for purposes of management.

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INTRODUCTION:

Access

A view across the Beaulieu River and the Needs Ore Point area towards Hurst Spit, as seen from near Inchmery House, Lepe Beach, Hampshire, 1st May 2017

.

The Beaulieu River estuary is a very attractive and beautiful place. It is notable for Beaulieu Abbey and Motor Museum, for Bucklers Hard and for the splendid Exbury Gardens. For the famous Exbury gardens and Exbury estate see:
Exbury Gardens and Steam Railway website. This provides valuable information on the history of the area.

For historic reasons, most of the region around the Beaulieu River is private; even the river bed is privately owned. There is, however, access to the general public at certain points. You can walk around a little of the estuary at Beaulieu Village. Bucklers Hard is a good place to visit. Here there is a tourist facility, with an entry fee, and there is a museum and there are boat trips on the river. It provides a good view of the estuary. There is a footpath from Beaulieu village to Bucklers Hard.

Elsewhere, there are few right-of-way footpaths in the area and most side roads and farm roads have notices warning of prohibited access. Thus most of the estuary is inaccessible without special permission. Bona fide researchers can apply to the authorities for a permit to visit certain areas. In spite of the general lack of land access, almost all the saltmarshes can be seen from a boat and they can be studied from various aerial photographs including those of Google Earth. There are a number of publications and Ph.D. theses which deal with the estuary.

The Beaulieu River estuary is not particularly good from a geological point of view because exposures are rare or absent now (once there were several clay pits). The estuary, however, is of much interest, though, regarding sedimentation and salt marshes. Compared with other Solent estuaries, it is relatively natural (although there has been much reclamation in the southwestern part). It tends to be used for research in cases where Southampton Water is quite unsuitable because of industrial pollution.

There are some other geological and environmental localities in the area which are good for field trips. These are places where there are interesting coast lines with public access. Some are listed below:

Lepe Beach. (at the mouth of the Beaulieu River estuary)
Calshot Spit. (not far to the east)
Keyhaven-Pennington Saltmarshes. (with an excellent coastal path)
Hurst Spit (now largely artificial, but of great interest)

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Safety and Risk Assessment

This website is not recommending that fieldwork take place in the Beaulieu River estuary. If it is undertaken by researchers they have to have special permission and they should be aware of the hazards.

The saltmarshes and mudflats consist of particularly soft and sticky mud. With certain exceptions as at "Hards" (e.g. Bucklers Hard), where gravel or bedrock is at the shore, the marshes are very difficult to traverse. There is often a bank or a relatively dry shore at the landward margin of the marsh. Plants such as Spartina and Atriplex (Halimione) give a firmness to the marsh, but there are numerous creeks and saltpans of treacherly soft mud. Researchers should work in pairs for safety and carry mobile phones. They should have permission and give notification as to where and when they are studying a location. Bird life should not be disturbed, especially in the nesting season.

The casual visitor at the public access locations should not go on to the marshes or mudflats, but is probably unlikely to wish to do so.

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INTRODUCTION:

Geomorphological History of the Beaulieu Estuary
- 17th Century

Coast of the Solent and Isle of Wight in 1693, southern England, based, with simplications and some interpretation, on Collins' chart

An early survey of the Beaulieu River estuary, Hampshire, based on the Commissioner's Report of 1698, and with annotations

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INTRODUCTION:

Geomorphological History of the Beaulieu Estuary
- 18th Century

A 1740 map of Beaulieu River estuary, Hampshire, and adjacent New Forest and Solent areas

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INTRODUCTION:

Geomorphological History of the Beaulieu Estuary
- 19th Century

Part of a map by Percival Lewis showing the Beaulieu River Estuary or Exe Estuary, Hampshire, in 1811

A modified part of an old map, 1811, showing Lepe and Exbury, West Solent, Hampshire

Part of an old topographic map of 1864 showing Lepe Beach, Hampshire, modified and partly redrawn from an imperfect original

Part of a 1810 Ordnance Survey map showing the Beaulieu River Estuary, Hampshire

Late Victorian geological map of the Lepe area, Hampshire

An 1885 topographic base map, with the geology superimposed, of the area around Lepe, including Lower Exbury and the mouth of the Beaulieu River, West Solent, Hampshire

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INTRODUCTION:

Geomorphological History of the Beaulieu Estuary
- 20th and 21st Century

An old, topographic map of parts of the New Forest and the Solent Estuaries, southern England, probably from about the 1920s

Location map for the New Forest and Southampton Water

Southeastern New Forest, 1924 map

A classified, false-colour, satellite image of the southern part (Beaulieu area) of the New Forest National Park, Hampshire, with only some partial interpretation

Chart showing Lepe Beach and the Beaulieu River, Hampshire

Old chart of the Beaulieu River estuary, Hampshire, and the surrounding area, with marine survey to 1955

Part of a 1909 topographic map of the Beaulieu River, showing the area around Gins and Lower Exbury

.

The 1934 topographic map of Lepe Beach and Calshot Spit, Hampshire, with roads updated to 1947

.

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INTRODUCTION:

Geological Maps

Old geological map, I.O.W.

Late Victorian geological map of the Lepe area, Hampshire

The geology of the Beaulieu River estuary, Hampshire, as surveyed in 1893, and with some updating

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INTRODUCTION:

Water and Sediment Chemistry

Some basic information on water salinity and chemistry and sediment chemistry, Beaulieu River estuary, Hampshire

The basic salinity and chemical features of the Beaulieu River estuary can be summarised, based largely on the work of Dr. Simon Houghton (1986) and papers to which he has made reference. The diagram above summarises most of the major aspects of the estuary.

The Beaulieu River rises in the New Forest. It is just a narrow stream but it has a 9 km long estuary. This is 3 km wide at the mouth but narrowing to less than 80m. in the upper estuary. The channel of the estuary is relatively shallow ranging from 1 to 8 m. in depth. The waters are generally unpoluted. Much of the estuary is homogeneous and vertically mixed, but there is considerable stratification at the head of the estuary Houghton (1986). At high water, salinity generally varies from 34.5 ppt. at the mouth to 18.5 ppt. at Beaulieu Village.

The incoming stream water from the New Forest is relatively acid with pH of 6.5. Selected streams running into the Beaulieu River gave means of 5.9, 7.2 and 6.2 for values on specific geological units. Incoming water from some ericaceous bogs in the New Forest can have values from 3.5 to 6.7 so it is not suprising that the Beaulieu River water is dominantly acid. The effect of the low pH of incoming water is a tendency to dissolve the small amount of carbonate, present at coccoliths and shell debris in the mudflat and saltmarsh sediments of the Beaulieu River estuary. This dissolution is marked above Bucklers Hard and thus no carbonate has been recorded upstream of that locality. Downstream, at Gilbury Hard, a small amount of carbonate appears. See Houghton (1986) for more details.

Organic matter is locally very high in the river above Beaulieu Millpond, but this is not surprising because of accumulation of leaves etc. Within the upper part of the estuary it is about 3.5% of bulk sediment. Further down in the stretch from Gilbury Hard (Exbury) to Lower Exbury it is about 9%, quite a high figure.

There is only limited information on trace elements. Zinc and manganese are fairly high at the incoming freshwater river and decrease down the estuary. Holliday and Liss (1976) showed a simple, inverse, linear relationship of both of these to salinity. This suggests that dilution is the main process and there is no evidence of major precipitation. Zn varies from about 45g/l to about 5g/l. This is not an usual figure for the type of mature sediment that is present. Mn ranges from about 115g/l down to 15g/l. This is also quite normal, considering the New Forest source area.

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INTRODUCTION:

The Upper Beaulieu River - a New Forest Stream

The Beaulieu River at Ipley, a narrow New Forest stream that flows into the much wider estuary of the Beaulieu River, at Beaulieu, Hampshire, seen in normal conditions

The Beaulieu River at Ipley in flood on 10 November 2008, transporting leaves from the New Forest to the Beaulieu River Estuary, Hampshire, England

Evolution of the Beaulieu River System of the southeastern New Forest in the Pleistocene according to Tremlett (1962) - modified diagrams

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LOCATION:

Beaulieu Village and Mill Pond

An old topographic map, 6 inch scale, of Beaulieu Village, Hampshire, and adjoining areas, surveyed in 1867-1868 and revised in 1907

The Mill Pond at Beaulieu Village, used in the past for tidal energy, photo 12th June 2008

Sluice gates open during river flood conditions and low tide at the southern end of the Mill Pond, Beaulieu, Hampshire, 10th November 2008

A view under the bridge from downstream of the sluice gates, which were  open during river flood conditions and low tide,  Beaulieu, Hampshire, 10th November 2008

The head of the Beaulieu River estuary near the sluice at Beaulieu Village, with Fucus on the mudflats and Ian West on the bank, low tide, 12th June 2008

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[BUCKLERS HARD]

LOCATION:

Bucklers Hard (historic shipyard village)

Part of a 1907 six inch map showing Bucklers Hard, Gilbury Hard and the Beaulieu River estuary, Hampshire

Bucklers Hard is a former ship-building yard, that manufactured ships for Lord Nelson's Navy. Because it provided hard ground, the downstream bank of the best Devensian incised meander was chosen for this industry (although the people at the time did not know the geomorphological history of the estuary). During the late Pleistocene the sea-level descended to minus 140 metres, and the English Channel was dry apart from the river channels. The Beaulieu River was a tributary of the Solent River, itself a tributary of the Rhone and Seine (flowing westward down the English Channel Valley).

The depth of the buried valley is not known exactly. About 10 metres to the base of the buried valley gravel seems likely, although it could be a little deeper (mostly less than 15 metres). The Solent River here was at about minus 20 metres in the central channel of the eastern part of the West Solent (i.e. offshore from the Beaulieu estuary mouth). It is quite likely that there was a relatively steep gradient in the southern part of the valley (perhaps down to minus 15 metres in the Gins area), by comparison with the deep mouth channels at Portsmouth, Chichester Harbour etc. However, at present there is no proven evidence for buried channel depths in the Beaulieu River estuary. Gilbury Hard represents another steep meander bank on the other side (notice the proximity of gravel pits to the channel). There is, of course, a large point bar under the saltmarsh opposite Bucklers Hard; Keeping Marsh is above another large one.

Bucklers Hard on the Beaulieu River Estuary, Hampshire, 2008

Above is shown a view down the degraded Devensian river bank at Bucklers Hard, with the lower part of the valley submerged by the sea. At one time this bank might have been cliffed, but the harsh periglacial conditions have led to a smoothing of contours. Examine the photograph in comparison with the map above, so that the relationship to the the 50 feet (15 metre) contour is seen. This is probably the place where the contour most closely approaches the channel.

Beaulieu River Estuary, Hampshire, seen from Bucklers Hard, looking eastward towards Gilbury Hard, February 2008

Ochre spring on the Atriplex middle saltmarsh at Bucklers Hard, Beaulieu River Estuary, Hampshire, 2008

The chalybeate spring or ochre spring at Iron's Well, Fritham, New Forest, Hampshire, 5th August 2007

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[EXBURY, GILBURY HARD] LOCATIONS:

Exbury Marsh near Exbury Jetty (South of Gilbury Hard)

An aerial photograph showing the degradation features of the saltmarshes on the east bank of the Beaulieu River estuary south of Exbury Jetty

The east bank of the Beaulieu River estuary at Exbury Jetty and southward (near Gilbury Hard) viewed from a boat at high tide, 22nd July 2008

A short creek in the saltmarshes of the Beaulieu River Estuary, at Exbury, Hampshire, December 2006

The bank of a creek in a Sea Purslane (Atriplex portulacoides), middle saltmarsh, at Exbury on the Beaulieu River Estuary, Hampshire, 2006

A creek in a Sea Purslane, middle saltmarsh, at Exbury, on the Beaulieu River Estuary, Hampshire, 13th December 2006

Ochre springs, from oxidation of pyrite, seeping into a salt pan on the high saltmarsh at Exbury, Beaulieu River Estuary, Hampshire, 13th December 2006

The origin of the ochre springs (iron springs) in salt pans and creeks in the Exbury area is a matter of interest. They occur elsewhere in the region where pyritic sediments are oxidised. The most well-known is Irons Well near Fritham, but there glauconite and siderite in the Bracklesham strata could be involved. Mr. Nicholas de Rothschild drew attention to the fact that pans of iron were used in the historic salt industry in the Exbury area (personal communication 2009). These could have provided additional iron, although the processes of weathering and diagenesis that might have occurred to pans of iron are not known. If the iron pans were submerged after use and buried to a shallow depth in sediment, they might have been pyritised. Oxidation of the pyrite could then provide iron for iron springs or ochre springs. The matter has not been investigated in detail and, in any case, some pyrite of natural origin would have been present in any case. The iron pans, though, might well have increased the quantity in places.

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LOCATIONS:

Exbury Marsh Sediments

Introduction

Creeks in a saltmarsh at Exbury Marsh, near Gilbury Hard, and part of the western saltmarshes of Beaulieu Estuary have been studied by Yining Chen. The bank of a creek was examined and samples were taken. Shallow cores were obtained within the Sea Purslane (middle marsh) and Sea Rush (upper marsh) parts of the saltmarshes near the creek that was investigated. Smear slides 1 to 10 were made from samples taken from the Sea Purslane marsh core at 10cm intervals from 0, marsh surface, and labelled 1 to number 10 taken at 90 cm depth. Samples 11 to 17 were taken from the Sea Rush marsh surface to a depth of 60cm.

Four smear slides were made of algal material from the bank of the creek. One impregnated thin-section through alluvial mud with plant roots was made.

Smear Slides of Saltmarsh Sediments

Sample No.

Depth

Particle Size,
without organic matter - phi

Particle Size,
with organic matter - phi

Sea Purslane Marsh Core

 

 

 

1

0cm

 

 

2

10cm

6.58

5.84

3

20cm

7.10

6.24

4

30cm

6.14

5.93

5

40cm

6.81

5.70

6

50cm

6.88

5.76

7

60cm

6.58

5.43

8

70cm

6.86

5.98

9

80cm

7.81

6.15

10

90cm

6.85

6.17

 

 

 

 

Sea Rush Marsh Core

 

 

 

11

0cm

 

 

12

10cm

6.48

5.92

13

20cm

7.46

6.30

14

30cm

7.29

6.30

15

40cm

7.15

6.13

16

50cm

7.01

5.98

17

60cm

6.51

5.85

Petrography of the Smear Slides - General

The samples consist predominantly of organic-rich, diatomaceous, pyritic, silty clay with some mica and chlorite (clinochlore). All proved to be generally similar except for lack of pyrite in samples 1 and 2 and a high quartz silt content in sample 7. All samples are unusual for the Solent estuaries in containing no calcite or aragonite, except for occasional foraminifera. There are no coccoliths and no bivalve shell debris. All samples contain clay and some subangular, quartz silt.

Petrography of the Smear Slides - Components

Clay
An major component of the smear slides is clay. The thin-section also shows that this is much more abundant than quartz silt. This has also been confirmed by XRD.

Glauconite (Glaucony or Glauconie)
Glauconite (sensu lato) or glaucony is present in small quantities in various slides. The fragments are small and within the silt size range. Green, unoxidised material was often seen.

Rutile
Amongst the finer components rutile is present both as needles and as geniculate twins.

Diatoms
Diatoms are extremely abundant throughout the sediment profile. Some samples, such as No. 16 are so rich in diatoms as to be almost diatomites. Diatoms present seem to be of genera like those present at Fawley Power Station (Goss in
Hodson and West, 1972) and seem to include Actinoptychus and Diplonei. No detailed study has been made. An interesting point is that in some samples air or gas is still contained within the chambers of diatoms superficially resembling Paralia. The abundance of diatoms suggests that diatom mucus should be present in the sediments.

Sponge Spicules
Siliceous sponge spicules are fairly common in the sediments, but not abundant.

Plant Debris
Plant debris, brownish in colour, and often as fibres is present throughout the samples. Narrow vermicular roots are present in some samples. Occasional plant spores were observed. Almost all the samples, except No. 13, contain much organic material. Houghton (1987) gave data on bulk sediments from the intertidal flat adjacent to the Exbury Marsh site. He found that the weight % organic matter was 9.2 just here. Similarly at locality 2, further down the estuary it was found to be 9.6 wt%. These are high figures and refer not to saltmarsh sediments, full of roots, but to tidal flat material. It is likely that the saltmarshes with saltmarsh vegetation have even higher contents of organic matter.

Pyrite
Pyrite is abundant in most samples. It mainly occurs as framboids, but some is present in some samples as minute cubic crystals. It is notable that pyrite is not present in the top two samples of the Sea Purslane core, that is within the the top 10cm. X-ray diffraction has not recorded pyrite in this top part. Field observations suggest oxidation of pyrite and production of goethite in the uppermost part.

Carbonate
Except for the occasional presence of foraminifera, this was not observed in the smear slides. However, foraminifera are relatively large and might not have been included in the fine material examined in the smear slides. A thin-section of salt-marsh alluvium with roots showed many foraminifera to be present, and thus the smear slides may be unrepresentative.

A thin-section of the upper silty sediments of the Sea Purslane saltmarsh, Exbury Marsh, Beaulieu River Estuary, Hampshire, showing Sea Purslane roots and a foraminifer

Data on the carbonate content of the intertidal mud-flats has been given by Houghton (1986). He found the following wt% carbonate in the bulk sediments:

Sample
No.

1
2
3
4
5
6
7

Map Ref.
.

SZ 442986
SZ 417988
SU 417003
SU 392023
SU 388024
SU 384024
SU 383029

Location
.

Lepe
Lower Exbury
Exbury Marsh - jetty
nr Carpenters Cottage
Quay, Beaulieu
Mill Pond, west side
Beaulieu River

Distance from
Mouth, km.

0
2.5
4
8.7
9.2
9.7
10.1

Wt.% Carb.
Bulk Sed.

7.9
3.8
2.6
less than 0.5
ditto
ditto
ditto

Wt.% Carb.
Fine Silt

0.5
0.4
0
0
0
0
0

Thus the carbonate is mainly coarser than fine silt, and it is does not extend up-estuary much further then Exbury Marsh. At that locality, which is the main site considered in this thesis, no significant carbonate was recognised in the fine silt sediments. This accords with Houghton's observations on lack of coccoliths at this point and on the present observations on the thin sections.

Clay Minerals (XRD)
Bulk sample X-ray diffraction data has shown the presence of muscovite (mica) and clinochlore (a variety of chlorite) in addition to some quartz. Clay mineral analysis showed that the clay minerals illite, smectite, and kaolinite are all present in the mud of the Exbury saltmarsh.

The percentages for the clay minerals of the less than 2 micron fraction have been estimated from XRD data as follows:

Illite - 46.3 percent
Smectite - 23.8 percent
Kaolinite - 18.5 percent
Chlorite - 11.4 percent

Discussion - Source of Components

Carbonate
The relative lack of carbonate is unlikely to be the result of non-deposition of the carbonate particles that are usually in suspension in the more open parts of the Solent estuaries (as for example at Fawley in Southampton Water (Hodson & West, 1972). Carbonate can be derived from bivalve shell fragments, coccoliths, foraminfera and reworked carbonate from Eocene strata.

Houghton discussed the pH of incoming Beaulieu River water. He found that the mean pH of river water entering the head of the Beaulieu Estuary is 6.5, whereas seawater at a salinity of 29ppt is 7.9. Seawater near the mouth of the Lymington Estuary has a pH of 8, at which carbonate is stable. He gave a convincing argument that the acid water of the Beaulieu River inflow are responsible for the dissolution of carbonate and its absence in the middle to higher parts of the Beaulieu Estuary. With regard to the present investigation, it can be considered that carbonate, perhaps only supplied in small quantity, has been lost from Exbury Marsh.

Glauconite s.l. (Glaucony or Glauconie)
This mineral is available in the local Tertiary sediments. It could be of river derivation from erosion of the Barton Group in the New Forest, but it is likely that it would be oxidised in this weathering environment. Because of its fresh condition it seems more likely that it has been derived from the cliffs of Christchurch Bay. If this is the case, then much of the quartz silt is probably also derived from the cliffs.

Rutile
Minute grains of this are widespread in the local clastics and has no special significance.

Pyrite
Reducing conditions with an abundance of organic matter account for the common occurrrence of pyrite in the samples. The top 10cm, however, seems to be oxidised. The oxic/anoxic boundary is placed at about 15cm. in the Sea Purslane saltmarsh between 2 and 3.

Clay Minerals
The assemblage of the main clay minerals, illite, smectite and kaolinite, is similar to that in the Holocene estuarine clays at Fawley, Southampton Water (Hodson and West, 1972). It is also broadly similar to the assemblages of clay minerals in the Eocene strata at Fawley (Gilkes in: Curry, Hodson and West, 1968). It also resembles the clay mineral composition of most of the Barton Group, including both the Barton Clay and Barton Sand, and of the "Lower Headon Beds" (Lyndhurst Member or lowest part of the Headon Hill Formation). All of these have major amounts of illite and smectite and a lesser proportion of kaolinite (Bale, 1984, fig. 23a). Thus the assemblage found in the argillaceous sediments of Exbury Marsh is very similar to that of the local Middle to Upper Eocene and its origin from the local Tertiary seems certain. The chlorite (probably clinochlore) is also common in local Tertiary sediments.

Thus the clays are almost certainly of dominantly Eocene origin. However, they could have been derived from the river system of the Beaulieu River within the New Forest National Park, where these sediments crop out, or from the cliffs of Christchurch Bay and Alum Bay, Isle of Wight where these strata are eroded by the sea (or from both). However the relatively common occurrence of unoxidised glauconite in the sediments of Exbury Marsh suggests an origin from the cliffs rather than from the leached and weathered soils of the New Forest.

Particle Size
Most of the the mineral components of the saltmarsh sediments are very small. Some of the clay crystals will only be fractions of microns in length. The particle sizes of the sediments when measured, however, are in the 7 phi range, i.e. fine silt. The quartz is mostly present as silt and thus in energy terms is comparable. It only represents a small fraction of the sediment. Thus the clay is flocculated or pelleted into silt-size particles.

Conclusions

The sediments are relatively uniform with no significant vertical change. The sediments of the Sea Purslane saltmarsh and the Sea Rush saltmarsh are similar. The deposits are of pelleted or flocculated clays with minor quartz silt, overall of fine silt particle size. Organic content is high, particularly in the form of roots. Diatoms are abundant, foraminifera are present, but in general, the carbonate content is very low, and undetectable in smear slides of the fine material. The clays have been derived and transported from the local Tertiary coastal cliffs of Christchurch Bay. They include illite, smectite and kaolinite and, thus, are expandible clays, greasy and sticky in overall character.

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[BEAULIEU RIVER - WEST BANK]

LOCATION:

West Bank, opposite Exbury

Dieback of Spartina saltmarsh near the main channel, west bank of the Beaulieu River estuary, Hampshire, opposite Exbury, 22nd July 2008

The west bank of the Beaulieu River estuary in the area opposite to Exbury does not seem to have degraded as much as on the more wave-affected east bank (although no systematic or quantitative study has been made). The Spartina of the saltmarsh seems to be flourishing except for a fringe area of a few metres at the main channel margin. Here there is clearly much dieback and not just erosion. The erosion that has occurred has not produced a sharp cliff but is rather irregular and limited in scale.

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LOCATION:

Lower Exbury,

(private, no access; part of the de Rothschild's estate)

Deteriorating saltmarshes at Lower Exbury, east bank, southern part of the Beaulieu River estuary, Hampshire, 21st July 2008

Details of deteriorating saltmarshes at Lower Exbury, east bank, southern part of the Beaulieu River estuary, Hampshire, 21st July 2008

The Lower Exbury saltmarshes were seen only from a boat in the main channel and on aerial photographs, and were not examined on foot. There has been significant retreat landwards of the main channel margin of the saltmarshes. Creeks within them have been expanding and the Spartina saltmarsh progressively decreasing in recent years. A low cliff marks the limit of the degrading saltmarsh as seen from a boat.

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[GINS NEAR WEST BANK, MOUTH OF BEAULIEU RIVER]

LOCATION:

Gins (Gins Farm and Royal Southampton Yacht Club)

(private - nature reserve - no access without permission)

Erosion and dieback of a saltmarsh relic at Gins, Beaulieu River estuary, Hampshire, June 2008

Some limited dieback and erosion of Atriplex portulacoides (Sea Purslane) on saltmarsh at Gins Jetty, Beaulieu River estuary, Hampshire, June 2008

A mid to high saltmarsh of Sea Purslane, Atriplex portulacoides   at Gins Jetty, Beaulieu River estuary, Hampshire, June 2008

Gins or Gins Farm is a former promontory of Pleistocene gravel and Eocene Headon Hill Formation extending ENE from St. Leonard's Grange and St. Leonard's Barn. See the geological map given above. Low land both south and north of it have been reclaimed from saltmarsh and mudflat. These low areas were once part of the estuary. Probably in the 13th century, when the barn was constructed as a type of warehouse for Beaulieu Abbey, the promontory and "hard" at Gins was almost the seaward headland of the Beaulieu River estuary. There was a low promontory of Pleistocene gravel at Warren Farm, but Needs Ore Point, further east, is a much younger feature.

At Gins there is a yachting jetty which provides a good view of an eroding saltmarsh. Perhaps because the fetch is greater here than further north (and thus there is more wave action), the saltmarsh has retreated more near the jetty than just up-estuary. The matter has not been studied in detail and there could be other reasons.

Beyond Gins to the north there is an old embankment and the topography and place names (Salternshill) suggest that this was an area of old salt workings. It is interesting that behind the embankment in dry summers there is some precipitation of a little halite, and, more unusually, some minor gypsum. This is the result of brine seeping through the bank and evaporating.

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LOCATION:

Black Water, between Gins and Needs Ore Point - Die-Back

Spartina saltmarsh die-back and creek enlargement at Black Water, between Gins and Needs Ore Point, Beaulieu River Estuary, Hampshire

A reclaimed area of mudflats and possibly saltmarshes, north of Black Water,Beaulieu River Estuary, Hampshire, showing a pattern of former creeks - aerial photograph, courtesy of the Channel Coastal Observatory, 2007

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LOCATION:

Needs Ore Point and Warren Farm Area, southern end of Beaulieu River Estuary

(Nature Reserve, access only by permit)

Needs Ore Point (Needs Oar Point) - General Topography

A distant view from Inchmery of Needs Ore Point, at the mouth of the Beaulieu River estuary, 27th July 2008

Needs Ore Point, Beaulieu River Estuary, Hampshire, shown in an aerial photograph of June 2007, and with die-back of Spartina saltmarsh in progress

The track to Needs Ore Point is on an old shingle spit, Beaulieu River Estuary, Hampshire, February 2009

Aerial view of the mouth of the Beaulieu River estuary and Needs Ore Point, showing areas of saltmarsh erosion at Inchmery

An old aerial photograph, modified, of the Needs Ore Point area, at the southern end of the Beaulieu River estuary, Hampshire

Needs Ore Point area is a private locality, used as a Nature Reserve (mainly for birds), with some yachting facilities and a few older houses. Access is only by permit, and it is closed off by gates. A few bird watchers use the locality. Natural England control the Nature Reserve. The place has a less peaceful history.

In the Second World War, Needs Ore Pointt was the site of a small airfield, an "Advanced Landing Ground", with more than a hundred Hawker Typhoons. a rather rough airfield, with a RAF campsite of tents adjacent. The airfield was adjacent to Warren Farm. According to Leete (2004). some of the Summerfield Tracking, airfield surface metal, and also various cables, are still there. I do not know the exact location but the geological map (Lymington Sheet) shows a stretch of Pleistocene gravel (a low horizontal terrace) both southeast and southwest of the farm and probably the airfield was probably on this firm and stable ground. The airfield runway with the mesh sheeting laid on the ground may not have been ideal for take off.

Unfortunately, there was a sad incident at Needs Ore Point. Typhoon, single-engined Typhoon aircraft flew from there. This type of aircraft had a large propellor which, when tail up was only 9 inch clearance from the runway. Two aircraft were scrambled for a sortie but the propellor of one caught on the rather irregular ground; the plane somersaulted, then cartwheeled and continued down the runway as small pieces and fire. A second aircraft hit the debris and exploded. That was one incident of Needs Ore Point. Another one involved reconstructing there the fragmentary remains of seven Germans found in a plane crash near Inchmery, Lepe. For more detailed information on the activities there see: Leete (2004).

With regard to saltmarshes, Needs Ore Point and the adjacent ground is a very interesting area. South of the Plateau Gravel outcrop there are a series of shingle spit developments and these to be continuing to increase. Access to the outer parts of the saltmarshes is actually by an old shingle spit, as discussed below. The north shore coast of the West Solent is being eroded during violent storms (as in 2014). Waves can also come up the channel from the east (Lepe Beach) although generally these are less effective, and so shoreline sediment transport is west to east and terminating in the Needs Ore Point area. The coast here changes and erosion can also occur from time to time.

Needs Ore Point - Geomorphological History

The development of Warren Farm Spit at the mouth of the Beaulieu River from 1868 to 1992, modified after Tubbs (1999) and Hooke and Riley (1991)

The history of Needs Ore Point is summarised in the diagram above, based on Hooke and Riley (1991) and Tubbs (1992). This clearly explains the sequence of events.

Needs Ore Point is at the Solent end of the Beaulieu River Estuary, as shown in the aerial photographs above. It is now in an area of extensive Spartina saltmarshes, but originally the surroundings were mostly water and mudflat. The Spartina saltmarshes, though are at present, however, in a state of serious die-back and erosion in some areas.

There is a raised track on gravel extending northeast from Needs Ore Cottages to a raised yachting Club House. Until about 1907 (Hooke and Riley, 1991) the gravel track was a narrow shingle spit, like Calshot Spit but much smaller. The cottages were adjacent to the original beach. The material of the spit consists of well-sorted subangular flint gravel. This has been derived from the low cliffs of the Thorns Beach and Park Shore area and moved by longshore drift driven by the prevailing southwesterly winds. The Solent shore to the southeast of the spit would originally have been mudflats, probably with some shingle.

At the slipway, adjacent to the Club House, there is a small recurved and former end to the spit. This is not the easternmost part of the Needs Ore Spit and, perhaps a little later, the spit extended from this area to the true end of Needs Ore Point a little further east. Note that this is former situation and now the remains of the spit are almost surround by saltmarsh are only visible as slightly higher and gravelly ground. Without the former gravel spit, though, there would be no hard for landing boats and no road and no Club House.

Accretion Phase

Build-up of shingle in the Warren Farm - Needs Ore Point area seems to have commenced in the 19th century. However from about 1900 onward there was development of Spartina saltmarshes from Lymington to the Sowley area. These undoubtedly gave much protection to the northern coast of the Solent between the Lymington and Beaulieu estuaries. The old cliff line in front of Pylewell House and east to Elmer's Court, Lymington is degraded and has been saved from direct attack by the sea because of the Lymington saltmarshes.

From the mid-20th century onwards the marshes have started to die-back and become eroded. This loss has greatly increased in recent years and they are now disappearing at a considerable rate. A good viewing point to see the destruction is Tanners Lane, where there is access to the shore at what is now the western end of the Lymington Saltmarshes. Soon the limit of the Lymington marshes will move to the west of Tanners Lane, opening-up a rejuvenation of the cliff line towards Lymington.

An aerial photograph, modified, of the Gravelly Marsh area and Warren Beach area, near Needs Ore Point, at the southern end of the Beaulieu River estuary, Hampshire, 2004

In about the mid 20th century there seems to have been increased erosion of the low gravel cliffs of the West Solent. This may have been connected to early phases of the Spartina saltmarsh loss, even though it was not so acute at that date. The erosion has taken place particularly in the Pitts Deep, Sowley and Thorns Beach area, west of the Beaulieu Estuary, although it is not known to what extent there were original beach shingle banks here. Now there are large number of modern groynes, here, (of the type with triangle landward structures) and much of the stretch is stabilised, at least for the present. With further rises in sea-level and "coastal squeezing" (the low-water mark moving landward to give a smaller intertidal zone) there is risk of renewed erosion. The erosion in the Pitts Deep, Sowley and Thorns Beach has supplied additional shingle. Much the early shingle (flint gravel) from that area has been deposited at Gravelly Marsh, to the west, which of course takes it name from this shingle (see aerial photograph above). There are several spit recurves at Gravelly Marsh and between some of them are small lakes.

The accretionary area of Warren Farm Spit and the older Needs Ore Spit, near Needs Ore Point, Beaulieu River Estuary, Hampshire, based on an aerial photograph of 2 June 2007 of the Channel Coastal Observatory

In the 20th century (shown between 1907 and 1985 on the diagram), an outer, parallel, shingle spit, Warren Farm Spit, developed. Undoubtedly this was the result of increased supply of shingle from the Thorns Beach area.

Between the two spits there was the accumulation of saltmarsh. This particular Spartina saltmarsh area is now the Bird Sanctuary. If you examine the aerial photograph of this, taken in 2007 and courtesy of the Channel Coastal Observatory , you can see that the Bird Sanctuary is an unusual saltmarsh in that the creeks flow northward away from the Solent coast, rather than towards it. This is because the saltmarsh is later in its development than the shingle beach to the south and the creeks could have had no exit in that direction. The creeks are not truncated and there is no indication of major transgression of the beach northward. The Spartina are at present in relatively good condition. The creeks have not significantly enlarged and there is little sign of die-back of the Spartina. This is one of the youngest Spartina saltmarshes in the Solent region, and may be one of the youngest in Britain. However, close examination of the aerial photograph shows some small locations of trouble, where there are brown patches of creek enlargement. It is not known why this has occurred, but it is probably a first sign of deterioration. In due course, with rising sea-level and perhaps other factors, the Bird Sanctuary will lose the Spartina and become mud-flats. This is the normal process for the Solent area at the present time, and it seems unlikely the Bird Sanctuary will be an exception.

Saltmarsh also developed to the east so as to form Gull Island, from what had previously been mudflats. By 1992 the Warren Farm Spit had been artificially joined across to Gull Island. This closed a channel which had been used by yachts.

Needs Ore Point - Saltmarsh Decline

Needs Ore Point, Beaulieu River Estuary, Hampshire, showing die-back of Spartina and erosion of saltmarshes by block-collapse, 20th February 2009

Erosion of saltmarsh by die-back of Spartina and then the development of small gullies and the collapse of blocks, Needs Ore Point, Beaulieu River Estuary, Hampshire

Degraded relics of Spartina saltmarsh near the Club House at Needs Ore Point, Beaulieu River Estuary, Hampshire, February 2009

Now in 2009 we observe the deterioration and decline of the Spartina saltmarshes. Some details are shown in the photographs above. There is die-back of Spartina particular near the front of the marshes. The die-back area is often very green because of the growth of the filamentous alga Enteromorpha. After the die-back has occurred there is often cracking of the mud with desiccation cracks, at least in summer. The roots of Spartina, which have had an important action in binding the sediments, are decomposing (although not totally lost). Erosion from the front takes place as a result of waves in the estuary. A typical convex profile tends to occur in this frontal region. Many small gullies develop, and these are probably initiated on the desiccation cracks (although this has not been proved). The desiccation cracks are almost certainly a cause of weakness which allows blocks of saltmarsh clay, partly bound by roots, to break away and fall in front of the degrading saltmarsh area.

Beaulieu River Estuary, Hampshire

Some die-back of Sea Purslane (Atriplex portulacoides) occurs here, as it does at Gins, Inchmery and elsewhere in the estuary. Where it has died back the bank seems to subside gently with a convex profile. The surface formerly occupied by Sea Purslane usually receives a green coating of Enteromorpha algae.

Needs Ore Point - Hydrobia Shells

Accumulation of small Hydrobia shells at the small recurved shingle spit, Needs Ore Point, Beaulieu River Estuary, Hampshire, 20th February 2009

The small gastropod Hydrobia is widespread in mudflat and saltmarsh environments. It lives on green algae. Here is an accumulation of the small shells on the small recurved spit near the Club House, Needs Ore Point, Beaulieu River Estuary.

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LOCATION:

Gull Island (at mouth of the Beaulieu River)

Composite, small-scale aerial photograph of the coastline at Lepe and the mouth of the Beaulieu River, West Solent, Hampshire, photos by CCO, with labels added

Gull Island at the mouth of the Beaulieu River Estuary, Hampshire, aerial photograph 2007, courtesy of the Channel Coastal Observatory

Gull Island is a relatively new feature, not shown on the old maps (above). It is oval island with saltmarshes and it is nature reserve for birds. In recent years a shingle beach connection with the mainland to the west was engineered, closing the Swatchway or Bull Run, a channel formerly used by small boats for entering or leaving the Beaulieu River. Since then shingle has moved on eastward to the former island. There has also been appreciable coastal squeeze here as sea-level has progressively risen. The low water mark has approached in geographically the high water mark, i.e. the intertidal mudflats have greatly reduce in width. The new shingle beach is not only building up but it is rolling over landwards, as is common for shingle beaches. It is killing the Spartina and rendering the remains of the saltmarsh easily eroded on the south side of the shingle beach. However, the matter is more complicated than this. There is some frontal erosion on the north, Beaulieu River, side of the saltmarsh. Large lumps are being eroded off. Faster than the erosion here is some some die-back which has produced a dead border or fringe on the north side. Another feature is considerable death of Spartina and much widening of creeks in the eastern part. This is the final stage of decline of Spartina saltmarshes and is also seen (and is more accessible) in the Inchmery area on the mainland opposite.

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LOCATION:

Needs Ore Point [Needs Oar Point] and Gull Island - Hooke and Riley Discussion

Hooke and Riley (1991) discussed (on pp. 214, 215) the area of Needs Ore Point area with references.

"The area near Needs Ore Point and the mouth of the Beaulieu River has been the subject of a number of research publications [some brief]: Human (1961); Coughlan (1982); Dobson (1964); Steers (1964) [an aerial photograph of the mouth of Beaulieu River]. It has been much investigated because it is owned by the Beaulieu estates and the changes have caused particular problems. Apparently the N-S channel was cut in 1726. The bars grew either because of Spartina colonisation and/or because of groyning, according to Human (1961), but the Beaulieu estate consider that much of the extension of the shingle bars took place in the winter storms of 1953/54 which coincided with the development of off-shore dredging [off-shore dredging where? - Shingle Bank?]. The bars became important wildlife reserves for birds. More recently the saltmarsh has eroded and with the widening of the N-S channel, Gull Island in particular has been subject to erosion (Coughlan, 1982). In 1985 the Beaulieu estates presented a Bill to Parliament to have the gap between Warren Farm Spit and Gull Island closed and a shingle barrier has now been constructed. Dobson (1964) who monitored the changes in these spits in the period 1953-1963, reveals that the rate and manner of growth has been very irregular and he suggests that the role played by Spartina is extremely important [but Spartina is in decline now, 2017]. He identifies three components of the spits: (1) an old shingle spit, lower than the main one and now deprived of shingle, (2) the main spit with a complex of laterals; (3) a narrow spit running out to the distal end along the seaward edge of the marsh colonised by Spartina townsendii. Steers (1964) suggests a similar mode of formation.

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LOCATION:

St. Margaret's Creek and adjacent area (near Lower Exbury)

Changes in saltmarsh creeks as shown by comparison of a 1950s aerial photograph and a 2004 aerial photograph, courtesy of the Channel Coastal Observatory, of the St. Margaret's Creek and adjacent area, at the southern end of the Beaulieu River estuary, Hampshire

The cliff edge of the saltmarshes between St. Margaret's Creek (Lower Exbury) and the Inchmery area, Beaulieu River Estuary, Hampshire, as seen from Needs Ore Point, enlarged photo February 2009

St. Margaret's Creek is at the southern end of the Beaulieu River Estuary. It is in a fairly exposed area just west of Inchmery where saltmarsh erosion os most severe. The actual creek and associated embankment are relics of historic efforts to reclaim part of the old estuarine mudflats or saltmarshes. Comparative areal photographs show the extent of saltmarsh deterioration here. A photograph of the cliffed edge of the saltmarsh between St. Margaret's Creek and Inchmery shows an unusual lamination in the eroded saltmarsh sediments.

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LOCATION:

Inchmery Shore (near Lepe)

See also, for continuation to Lepe Beach eastward:
Solent - Lepe Beach and Stone Point Website

Deterioration of Spartina and Atriplex saltmarhes by creek enlargement and die-back between Inchmery and Lower Exbury, near the mouth of the Beaulieu River Estuary, Hampshire, CCO image, 1st August, 2004

Final maze-type  decline and erosion of saltmarsh, between Inchmery and Lower Exbury, Beaulieu River Estuary, Hampshire, 2007

Changes in the eroding saltmarshes at the shore, half a kilometre west of Inchmery House, Beaulieu River estuary, Hampshire, near Lepe Beach, from 1993 to 2008

Notice in the above photographs, and in the aerial photograph next above, the presence of maze-like decline of saltmarshes, with near-circular 'dead ends'.

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The area of former saltmarshes at the shore, half a kilometre west of Inchmery House, near Lepe Beach, Beaulieu River estuary, Hampshire, seen on the 22nd June 2017, after die-back, degradation and erosion

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A whale back erosional feature at Inchmery shore, near Lepe, Beaulieu River estuary, Hampshire, from 1993 to 2008

Near Inchmery there was previously an extensive area of saltmarsh that could be seen from the road or adjacent footpath. This has now reduced in size as a result of erosion, which has been proceeding for two or three decades. The reason for the erosion is not clear. It is probably, at least in part, due to rising sea level. It is not known, however, whether changes in the spit in the Needs Ore area has affected this region. The spit has extended eastward and this should give more protection to the saltmarshes. However, the details of tidal processes here are not known, and in any case the area is subject to the action of waves coming from the southeast (Spithead) area.

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A transition point from Beaulieu River shore facies to Lepe Beach shore facies, at a small headland west of Inchmery House, Lepe Beach Hampshire

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LOCATIONS AND HISTORY:

St. Leonards Grange, Tithe Barn, A Very Large Mediaeval Barn

St.Leonards Grange, Tithe Barn, near Gins and the original entrance to the Beaulieu River, Hampshire, 28th August, 2017

Remains of St. Leonard's Grange, Tithe Barn, once the largest Mediaeval, Tithe Barn in England, near the Beaulieu River, Hampshire

A general overview of the remains of St. Leonard's Grange, Tithe Barn, near the Beaulieu River, Hampshire

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NETTLESTONE SANDSTONE

Nettlestone Sandstone? (The Ripple-Laminated Rock in the Walls)

The Nettlestone Sandstone Member of the Headon Hill Formation, Solent Group, on the beach at Nettlestone Point, northeastern Isle of Wight

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[this section is being reorganised.]

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[stratigraphy and sedimentology] ---------------

In the walls of the St. Leonard's Grange, Tithe Barn, there are some unusual rocks that have been extensively used in construction of the wall. There are numerous examples of an grey, unfossiliferous, ripple-laminated, calcareous sandstone. This is probably the Nettlestone Sandstone ("Nettlestone Grit")of the Headon Hill Formation of Nettlestone Point on the Isle of Wight, although this has not been confirmed, as far as I know, by a detailed petrographic study.

The small borings into the rock, usually seen on one surface, are the results of its occurrence on a shore as a rock ledge. It seems to have been almost entirely collected from a beach.

A single block was found that shows that it has been affected by an earthquake during deposition. (This is not rare in the region, because the Eocene strata of Bournemouth and Hengistbury Head have been affected by the Middle Eocene impact of the Algerian Plate on the European Plate and thus show the effects of Eocene earthquakes.)

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Ripple-laminated, calcareous sandstone in the walls of St. Leonard's Grange, Tithe Barn, near the Beaulieu River, Hampshire

Climbing-ripple, cross-laminated,  calcareous sandstone in the walls of St. Leonard's Grange, Tithe Barn, near the Beaulieu River, Hampshire

Symmetrical wave ripples with upbuilding of bi-directional cross-lamination, in the walls of St. Leonard's Grange, Tithe Barn, near Beaulieu, Hampshire

A close view, with mm. and cm. scale, of the cross-laminated sandstone that has been extensively used in the walls of the St. Leonard's Grange, Tithe Barn, near Beaulieu, Hampshire

A stone surface bored by tube-worms in the wall of St. Leonards's Grange, Tithe Barn, near Beaulieu, Hampshire, 26th August 2017

A bored block with an attached, modern,  oyster in the wall of St. Leonard's Grange, Tithe Barn, near Beaulieu, Hampshire 26th August 2017

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OTHER ROCK TYPES

Bembridge Limestone etc.

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A block of Bembridge, lacustrine limestone in the walls of St. Leonard's Grange, Tithe Barn, near Beaulieu, Hampshire, with internal moulds of Viviparus

An irregular block of Bembridge Limestone, with mouldic secondary porosity, in a wall of St. Leonard's Grange, Tithe Barn, near Beaulieu, Hampshire

The blocks shown above have mouldic secondary porosity, caused by the dissolution of the aragonitic shells of freshwater gastropods. This type of lithology is common in the Bembridge Limestone strata of the, nearby, Isle of Wight.

A small slab of  limestone with modern marine borings, seen in a wall of St. Leonard's Barn, near Beaulieu, Hampshire

There are interesting ruined walls that were part of St. Leonard's Barn, a very large mediaevial barn on the west side of the Beaulieu River estuary. It is very conspicuous from the road if you drive on down the lane from Bucklers Hard towards the south. It is located near to Gins, a "Hard" or location where hard ground (gravel) reaches the shore of the muddy Beaulieu River estuary. This is an obvious landing place, now in use by the Royal Southampton Yatch Club. The ruin is protected by Natural England, and there is no access to the interior.

The barn is quite interesting geologically because it contain a number of unusual limestone types. There is slabby, ripple-lamined, limestone with interesting sedimentary structures. Some of the ripples are climbing ripples, and the original rock was heterolithic to some extent, with some development of clay flasers. Some of the limestone contains low-salinity gastropods, such as Viviparus. There are also some minute gastropods in at least one block. Other limestones seem to lagoonal, bivalve biosparrudites. Some of these may be of Purbeck origin, but the Praaexogyra distorta, so common in the Middle Purbecks was not seen. However, no detailed study was made and these comments are only the result of a superficial glance at what can be seen from the road.

It is interesting that there are also small slabs of limestone which have been bored by marine organisms and are obviously material collected from a beach. The cementing matrix or mortar is very much like cobb. It contains rather angular and rather brown flint pebbles. They are more likely to be of beach origin than New Forest gravel pebbles because they do not seem much podzolised. They are not heavily battered from an open beach, though. Once again, only a superficial glance was made. Probably the stones of the barn warrant more thorough study of provenance, although, of course, this may have already been undertaken.

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LOCATION:

Lepe Beach, West Solent

Go to webpage on: Solent - Lepe Beach and Stone Point ?

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FUTURE OF THE BEAULIEU RIVER ESTUARY?

(with rising sea-level)

Relative sea level is now rising in the Beaulieu River estuary and adjacent area at about 2mm per annum. The extent of sea-level rise over the next hundred years, as a result of global warming, is not known exactly but could be 60cm or more. The quantitative effects are not known but the general trend is obvious. The processes involved are taking place to some extent now and are almost certainly going to increase.

Some processes listed below are quite likely to happen, but there is no certainty and it is not clear as to exactly when and how. The Holocene transgression is almost certain to continue, unless collosal and extremely expensive measures are taken to try to combat it. The English Channel was dry only 10,000 years ago; the New Forest is still dry at present but it consists of marine sediments full of shells from a former sea and will return to marine conditions in the long term. Sea level is rising; the coast should retreat.

Possible future events in the area of the Beaulieu River estuary resulting from rising sea-level:

1. Generally the gradient between the present high and low water is gentle, but the slope of the bank or cliff above high water is usually fairly steep. Thus as the high water level rises the position of the high water mark is only displaced a little when seen geographically, i.e. from above. The low water level moves landward to a much greater extent on the gentle slope. Thus the low tide mark or drying line has been moving progressively closer to the cliff or bank of the estuary. The intertidal zone is narrowing. This will continue until there is very little intertidal zone in the area.

2. The saltmarshes are now both eroding and showing dieback as a result of rising sea level, and probably other factors. Those on the east bank, which is subject to more wave erosion, will disappear in the Beaulieu River estuary in a few decades. Those on the west bank will last longer (as in Southampton Water) but will eventually decline.

3. Saltmarshes have been lost and are also being lost on the north shores of the West Solent between the Beaulieu River and the Lymington River, as sea level rises. They have not always been present here and the sea has recently started to reactivate the old, back-marsh, cliff line. There has long been erosion in the Park Shore - Thorn Beach area but this is likely to extend to the Tanners Lane area (where there has been much recent loss of saltmarsh) and later further west towards Lymington. If Hurst Spit is breached for any significant period of time, or if the 1-in-250 year hurricane (the 1824 or 1703 type event) reappears, then erosion of the shore between the Lymington River and the Beaulieu River could be major (like that at Chilling, near Fareham).

4. Substantial erosion of gravel between the Lymington and Beaulieu Rivers could release a large quantity of potential beach material. This will travel towards the Needs Ore Point area and may lead to extension of the spit, and possibly even a blocking and silting-up of the Beaulieu River estuary (as has already happened in the case of small estuaries west of Lepe Beach)

5. Some low ground, particularly that which has in the past been reclaimed from the sea, may be flooded. Much of the Black Water area at the southwestern end of the estuary is low and was formerly marsh, mudflats or sea. Some managed retreat might perhaps be discussed in the future, particularly when the presently existing saltmarshes and mudflats become mostly submerged, thereby reducing the area of habitats suitable for some bird life.

There is nothing remarkable about the possible processes listed above. The main question is will they happen so slowly as to not affect the present generation, or will drastic changes start to become visible in the next ten years or so. Watch the Inchmery and Lymington saltmarshes for a first indication.

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OVERVIEW:

Future Changes in the Mainland Coast of the West Solent

The mainland coast of the West Solent is changing from a varied coastline, originally with several small harbours and inlets in addition to harbours still surviving. It once had extensive mud flats but in the 20th century extensive Spartina saltmarshes developed. These are now eroding and declining fast. Mud flats have greatly reduced in width with coastal squeeze from rising sea-level (i.e. steepening shores - low water mark approaching high water mark in location terms). Cliff erosion on the north shore of the West Solent is limited now but is increasing and will increase greatly. In particular, the saltmarshes east of Lymington will disappear and fresh cliffs of Pleistocene gravel will develop. Such cliffs will then provide masses of shingle which will move with longshore drift northeast into large spits. One of these will close or partially close the Beaulieu River mouth. The north shore of the West Solent will become a coast of shingle beaches, somewhat like those of the Hayling Island, Bracklesham Bay coasts in the more open, Spithead region. This trend towards cliffs, shingle beaches and spits will happen in any case with rising sea-level. The change in this direction would be more drastic if Hurst Spit were to be destroyed by rising sea levels and hurricanes in the future.

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SUPPLEMENT - MORE ON - NEEDS ORE POINT AND GULL ISLAND AREA (additions of 2017)

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Some Old Maps of Lepe Beach and the Beaulieu River Mouth Area [with some duplication, that may be removed in a subsequent re-organisation phase]

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Coast of the Solent and Isle of Wight in 1693, southern England, based with simplications on and some interpretation on Collins' chart

The very old map shows extensive mudflats in the West Solent, generally corresponding to the mudflats shown on later maps. These became saltmarshes after about 1900 when Lord Montagu introduced Spartina to the Beaulieu River estuary. As noted elsewhere, these saltmarshes are now in decline because of death of Spartina and modern erosion. The old map tends to show the West Solent as a rather restricted estuary protected from major wave action (from the southwest) by the Shingles Bank and Hurst Spit. The latter has not changed much in size but it is sometimes overwashed now. The Shingles Bank has been subject to dredging for shingle and has presumably declined in size; the writer does not know the extent of this. In overall view the formerly rather protected estuary with mudflats is turning into a narrow stretch of sea with cliffs, at least between Lymington and Calshot Spit. The Calshot part has already been converted to a coats cliffs quite long ago. However, the stretch from Lepe Beach (now with erosion near Inchmery House) towards Lymington is in progress of changing to a seaway with cliffs on both north and south coasts. Rising sea-level, loss of Spartina and probably major damage to the Shingles Bank and Hurst Spit are factors. Sooner of later the coast will be almost completely cliffed from Lymington to Lepe Beach, with, of course, some loss of land due to erosion. Maps and photographs show how this beginning to take place. The cliff and shingle beach development and the longshore drift eastwards means that further major development of a spit or spits at the mouth of the Beaulieu River is almost inevitable (but will it almost block the Beaulieu River in due course? Look at the trend and see photographs showing erosion from Lepe Beach to Tanners Lane and Pitts Deep area, near Lymington.).

[duplicate map deleted. 10LP-Lepe-Exbury-500.jpg. Lepe, Exbury and the Mouth of the Beaulieu River in 1811. see the same image high in this webpage]

Late Victorian geological map of the Lepe area, Hampshire

An 1885 topographic base map, with the geology superimposed, of the area around Lepe, including Lower Exbury and the mouth of the Beaulieu River, West Solent, Hampshire

Southeastern New Forest, 1924 map

Chart showing Lepe Beach and the Beaulieu River, Hampshire

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Shingle transport and spit development near Lepe Beach and the mouth of Beaulieu River, Hampshire, southern England, a modern map

Recent changes in the spit at the mouth of the Beaulieu River, near Inchmery and Lepe Beach, Hampshire, 1st May 2017

Distant views of the end of the long shingle spit, Gull Island etc, at the mouth of the Beaulieu River and near to the old Needs Ore Point, Lepe Beach, Hampshire, 1st May 2017

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Supposed route of Roman Road to Stone Point, near Lepe, Hampshire

Map of the Lepe Beach, area, Hampshire, showing old wrecks

Reids, 1905, hypothetical maps of the Ictis Causeway and the Solent River, Solent Estuaries, southern England

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APPENDIX - NEEDS ORE POINT IN THE SECOND WORLD WAR

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See: Leete, J. 2004. The New Forest at War. Sutton Publishing. 144pp.

This paperback book has a short section regarding a temporary airfield at Needs Ore Point in 1944. See "Typhoon Tales", p.51 et seq. Some brief notes from this follow. Interested persons should see the whole chapter (and other parts of this interesting book).

Steel mesh plates and sheeting were laid on the ground in field at Needs Ore Point. The farmhouse there was used for operations. The area was surrounded by anti-aircraft batteries. Four squadrons were under canvas at this location. Typhoon aircraft were used and these carried 500 pound bombs and had long-range fuel tanks.

The temporary airfield was apparently quite rough. The Typhoon planes had very large propellers with only 9 inch clearance from the ground. In April 1944, one of these tried to take off with the nose pushed too far forward. The propellor caught on the ground and plane exploded. A second Typhoon crashed into this. The wreckage of both was cleared and two replacement Typhoons took off to complete the mission. There is also a note about a German aircraft that was found wrecked, across the Beaulieu River from the airfield at the edge of the Exbury Estate and close to the Solent (i.e. not far from Lepe Beach). Items were transported to the Needs Ore Airfield. Details are not appropriate here.

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Bibliography of the Geology of the Solent - General Section - Undivided


Bibliography of Geology of the Solent - Topics Alphabetically

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ACKNOWLEDGEMENTS

We particularly thank Mr. Nicholas de Rothschild for kind permission to study the saltmarshes of the Exbury area. We much appreciate his advice and comments on ochre spring associated with salt pans at Exbury and for other information. Several other people have given us assistance relevant to this brief account of the Beaulieu River estuary. It was very helpful of Bob Lord and his colleague Mark, the staff of the Natural England centre at St. Leonards, to guide us with regard to changes in the southern part of the estuary and to discuss nature reserve areas of the margins of the Beaulieu River, and to give us permission to visit certain areas. We very much appreciate discussion in the field with Toru Tsuzaki. Dr. Malcolm Hudson's Ph.D. thesis on the estuary provides invaluable background information, and so too does that of Dr. Simon Houghton.

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BIBLIOGRAPHY AND REFERENCES

Please go to the:

Solent Geology Bibliography,

and

New Forest Geology Bibliography

Some additional references or papers of particular relevance will be given below:


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Exbury Gardens. Go to:
Exbury Gardens and Steam Railway website.
"Lionel de Rothschild moved to Exbury in 1912, purchasing Inchmery House with plans to create his gardens in the land surrounding this house. Unfortunately this didn't prove to be possible and so in 1919 he purchased the Exbury Estate, neighbouring his Inchmery home, and set about creating the world famous Gardens.
Exbury village and Estate owe their appearance to the Mitford's and Rothschild's, who created the mix of architectural designs seen today. The Rothschilds of all the owners have probably had the greatest impact on the appearance of this quintessential Hampshire village and Estate...." [continues]
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Green , C.P. and Keen, D.H. 1987. Stratigraphy and palaeoenvironments of the Stone Point deposits: the 1975 investigation. Pp. 17-20 in: Barber, K.E. 1987, Wessex and the Isle of Wight, Field Guide. Quaternary Research Association. Prepared to accompany the Annual Field Meeting held at Southampton and Cowes, 21-25 April, 1987. 180 pp. No abstract available, so extract of introduction given below: The Pleistocene deposits at Stone (SZ 457984) were first described by Reid (1893) and subsequently by Palmer & Cooke (1923), West & Sparks (1960) and Brown et al (1975). Figures 1 and 2 indicate the arrangenent of the deposits investigated by Brown et al (1975). On the foreshore, organic clays including several beds of Phragmites peat occupy depressions in the surface of an underlying Lcwer Gravel. In the cliff, the relationship of these deposits to an overlying Upper Gravel can be traced. .. The full extent of the organic deposits and the Upper Gravel is unknown, but they are not present at Lepe Coastguard House, 0.61 km west of Stone, or at Cadland, 2.01 km north-east of Stone. At both these places a low terrace gravel of the River Solent rests directly at Tertiary bedrock, and has a base at approximately the same level as the base of the Upper Gravel at Stone. The Lower Gravel at Stone, and the organic deposits appear therefore to occupy a depression cut in the Tertiaries to below present sea level. .. Stratigraphy .. This is the lowest member of the Pleistocene succession at Stone. In composition (Table 1) it resembles terrace gravels of the former River Solent. A maximum thickness of 2.6 m of gravel was seen in excavations beneath the modern beach without reaching a base. In sane places the upper part of the Lower Gravel, a bleached horizon and iron pan resembling parts of a podzolic soil were seen... [continues with: Fig. 1 - an important plan from the 1975 paper of Brown et al showing the details of the beach with pit numbers and locations of bulk samples; Fig. 2 Sections through the Pleistocene deposits, also from Brown et al. The original short paper is very useful and it should be consulted.]
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Hinton , D.A. and Insole, A.N. 1988. Hampshire and the Isle of Wight: Ordnance Survey Historical Guides. George Phillip, Ordnance Survey. 159pp. ISBN 0-540-01137-1. Hardcover. [This guide is useful for the topographical history of the coast of the Solent and the Isle of Wight and inland areas such as the New Forest. Maps from the first series of the nineteenth century Ordnance Survey, covering the whole of Hampshire and the Isle of Wight are compared with modern Ordnance Survey Landranger series of maps. There is explanatory text and old photographs. The value of this in terms of geology and geomorphology is that it shows the coast has changed with development, silting-up or erosion. The Solent shores (e.g. map 47 - Lymington) are very different with many salterns and salt works. The extent of erosion at Barton and Hordle cliff (map 46 - Milton) can be seen. There are photographs of Ventnor in 1890 and old Blackgang Road, Niton in about 1895.]
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Historic England, 2017. Strategic Stone Study; Hampshire, Including the New Forest National Park, Part of the South Downs National Park, and the cities of Southampton and Portsmouth. Published May 2017. 29pp, including - further reading (a short reference list). Available free online as a pdf file: Hampshire_Building_Stone_Atlas.pdf. Published by Geckoella, the British Geological Survey and the South Downs National Park. Hampshire Strategic Stone Study 1. A short, concise account, but with many good, clear photographs of stones used in buildings (does not show petrographic photographs).
[Includes: Hythe Sandstone (Lower Greensand); Sandgate Formation (Bargate Stone or Bargate Sandstone); Folkstone Formation (Carstone, Iron Sandstone, Forest Stone, Clinker); Selborne Group, Upper Greensand Formation (Malmstone, Malm Rock, Bluestone, Blue Rag, Firestone); Upper Cretaceous, Chalk Group, White Chalk Subgroup, Quarry Flint ('Fresh' Flint); Chalk ('Clunch'), Newhaven Chalk Formation (Hambledon Chalk), Sarsen Stones (Greywethers, Bridestone); Reading Formation Sandstone and Ironstone, Thames Group - Harwich Formation Basement Bed, London Clay Cementstone (septaria), Quaternary Flint, Beach Pebble Flint, Ferricrete (Heath Stone, Iron Pan, Ironstone Conglomerates, Ferrells, Tufa, Travertine, Caen Stone, Bath Stone, Chilmark Stone, Portland Stone, Purbeck Stone, Purbeck Stone-slate, Horsham Stone Slate, Ventnor Stone, Green Ventnor Stone, Mixon Stone (with Fasciolites = Miolina), Nettlestone Sandstone (Solent Group, Netley Abbey, Porchester Castle, Tithe Barn), Quarr Stone, Bembridge Limestone.]
[Re. the Beaulieu River Estuary, this is relevant because of the occurrence of many blocks of Nettlestone Sandstone (briefly described in this publication) in the St. Leonard's Grange, Tithe Barn. The same rock is present in Netley Abbey and in Porchester Castle.]

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Holland , A.J. and de Rothschild. 1982. Our Exbury: Life in an English Village in the 1920's and early '30's. By A. J. Holland and Edmund de Rothschild. 78 pp. booklet. Published by Paul Cave Publications Ltd., 74 Bedford Place, Southampton. Printed by Brown & Sons (Ringwood) Ltd., Crowe Arch Lane, Ringwood, Hampshire.
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Hooke , J.M. and Riley, R.C. 1992. Historical changes on the Hampshire coast 1870-1965. Proceedings of the Hampshire Field Club and Archaeological Society for 1991, v. 47, pp. 203-224. [Development of Needs Ore Point and Warren Shore Spit at the mouth of the Beaulieu River near Lepe Beach. See also Tubbs (1999) for a diagram based on this work.]
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Jowitt , R.L.P. and Jowitt, D. M. 1978. The Solent and its Surroundings. Terence Dalton Ltd., Lavenham, Suffolk. 142 pp. By R.L.P and Dorothy M. Jowitt. Photographs by Robert E. Jowitt.
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Kirwan , M. and Temmerman, S. 2009. Coastal marsh response to historical and future sea-level acceleration. Quaternary Science Reviews, vol. 28, Issues 17-18, August 2009, 1801-1808. Volume on: Quaternary Ice Sheet - Ocean Interactions and Landscape Response. By Matthew Kirwan and Stijn Temmerman.
Abstract:
We consider the response of marshland to accelerations in the rate of sea-level rise by utilizing two previously described numerical models of marsh elevation. In a model designed for the Scheldt Estuary (Belgium-SW Netherlands), a feedback between inundation depth and suspended sediment concentrations allows marshes to quickly adjust their elevation to a change in sea-level rise rate. In a model designed for the North Inlet Estuary (South Carolina), a feedback between inundation and vegetation growth allows similar adjustment. Although the models differ in their approach, we find that they predict surprisingly similar responses to sea-level change. Marsh elevations adjust to a step change in the rate of sea-level rise in about 100 years. In the case of a continuous acceleration in the rate of sea-level rise, modeled accretion rates lag behind sea-level rise rates by about 20 years, and never obtain equilibrium. Regardless of the style of acceleration, the models predict approximately 6-14 cm of marsh submergence in response to historical sea-level acceleration, and 3-4 cm of marsh submergence in response to a projected scenario of sea-level rise over the next century. While marshes already low in the tidal frame would be susceptible to these depth changes, our modeling results suggest that factors other than historical sea-level acceleration are more important for observations of degradation in most marshes today.


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Leete, J. 2004. The New Forest at War. Sutton Publishing, 144 pp. Paperback book. (Not geological but of local history interest regarding the Beaulieu Estuary, and showing the former importance of Needs Ore Point.)
Example extract: "During the same month as that terrible crash [of Typhoons] on the airfield on the 18th April 1944, just a month or two before D-Day two squadrons took off from the advanced landing ground at Needs Ore Point to patrol south of the Isle of Wight. We had it on good authority that something was afoot. We had been airborne for about fifteen minutes or so and we were circling some 20 miles out to sea. Suddenly in the distance to the east of the island, a formation of German aircraft was sighted as they made an approach for the English coast. Naturally we turned to give chase. The German formation wheeled away and eluded us, turning eastward towards France, and out of range. One lone aircraft, however, seemingly unaware of our existance, was later observed flying straight and level, slogging slowly and earnestly towards the shores of the south coast. Within a short space of time that medium bomber, a Ju188, very unlucky to find a Typhoon squadron airborne, was lying in a horrible wreck in a field on the edge of the Exbury estate, close to the Solent and a stone through from our base at Needs Ore." [unpleasant details follow regarding casualties which are unsuitable for reproduction here]. .. continues.
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Mathers, S.J. 1982. The Sand and Gravel Resources of the Country Around Lymington and Beaulieu, Hampshire: description of parts of 1:25,000 sheet SU 20,30 and 40 and SZ 29, 39 and 49. 58 pages, diagrams, tables etc. 0 11 887417 9. Mineral Assessment Reports No 122. British Geological Survey.
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New Forest District Council 2004. New Forest Coastal Management Plan, February 2004. C7, Zone 7: North West Solent Shore. Available on the internet at:
North West Solent Shore.
In this secluded part of the Solent shore, mudflats, saltmarshes and tidal creeks fringe a well-wooded, agricultural landscape. The zone is of outstanding scenic quality, and of considerable value for nature conservation. The majority of the area is in the ownership of a few large country estates. Other than at Lepe Country Park, public access is limited, and indeed much of its character and attractiveness is due to the resulting sense of isolation. .. [continues]
It includes this note of particular interest re erosion:
"C 7.6 - Parts of this low-lying shoreline are vulnerable to flooding, particularly the eastern side of the Lymington River estuary. Erosion of low cliffs and the marshes is evident, and landowners along the shore have undertaken a number of small coast protection schemes some with the advice and assistance of the District Council. A shingle bank has been constructed across Bull Run, an artificially created channel, to join Gull Island to Warren Farm Spit, in order to stem the rapid erosion of the bird sanctuary. More substantial works have been necessary at Lepe, where erosion threatens properties and the road near the shore; a major concrete structure protects the road. In front of Lepe House, timber coast protection works were built in 1991 by the landowner with a grant from the County Council, in return for a public right of way being established along the top of the new timber revetment. To the east, beyond Stone Point, the timber revetments are frequently undermined during storms, resulting in erosion of the soft, sandy cliffs. Similarly, the shingle beach north of Stansore Point is relatively unstable despite the timber groynes and revetments that have been constructed. The beach was breached extensively in 1991, resulting in damage to the cross Solent Isle of Wight gas mains. Parts of the heavily wooded foreshore, which forms part of Cadland Estate, have been lost over the last 50 years."
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Office of Climate Change, Department of the UK Government.
Online at:
Office of Climate Change.
The Office of Climate Change (OCC) was set up in September 2006 and works across Government to support analytical work on climate change and the development of climate change policy and strategy. Many government departments are involved in tackling climate change, or in helping the UK and other countries adapt to its possible future impacts. The OCC is a shared resource for all departments.
The OCC's role is to:
Run policy focused projects on difficult cross-cutting issues
Programme manage (at a high level) the UK's climate change commitments
Consolidate analysis and co-ordinate between departments
Act as an advocate for climate change issues within government
Since the creation of the Department for Energy and Climate Change (DECC) in October 2008 the role of the OCC has evolved. The OCC has become part of DECC, and will lead the development of the department's overall strategy. However, because of the complexity of the climate change and energy challenge it will continue to retain a distinctive role and cross-cutting way of working, with other departments having a role in the Office's funding and governance. [continues]

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See also the continuation of this webpage at Lepe:

Lepe Beach and Stone Point

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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 descriptions 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. Places need not 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 Yining Chen, Saltmarsh specialist and hydrodynamicist, who completed a Ph.D thesis on the Beaulieu River Estuary, Hampshire in 2009

Webpage - written and produced by:


Ian West, M.Sc. Ph.D. F.G.S.

Ian West has been awarded the R.H. Worth Prize for 2008 of the Geological Society of London for the application to amateur geology of the website, the Geology of the Wessex Coast, of which this webpage is a part. .

and by

Dr. Yining Chen, a saltmarsh specialist and hydrodynamicist formerly at the National Oceanography Centre, Southampton University, and now at the university at Xiamen, China.