Loess in Britain XII: The Weald

Burrin, P.J.  1981.  Loess in the Weald.  Proceedings of the Geologists Association  92,  87-92

Wooldridge, S.W.  1932.  Soil and civilization in South East England.  South Eastern Naturalist and Antiquary 37,  56-58

Wooldridge, S.W., Linton, D.L.  1933.  The loam terrains of South East England and their relation to its early history.  Antiquity 7, 297-310.

 "The overall impression gained from these studies is that loess or loessal-derived sediments may be widely distributed in the Weald.  However, a recent discussion on the contribution of loess to soils in lowland Britain (Catt 1978) reports that reconnaissance of large areas of the Weald, especially the Weald Clay outcrop, revealed insignificant amounts of loessal material. Clearly there is controversy as to whether or not loess, or loessal-derived deposits, exist in this area, and in this context the results of a continuing research programme in the Weald are of relevance."  (Burrin 1981)

 

Loess in Britain XI A.S.Kennard (1870-1948)

Preece, R.C.  1990.  Alfred Santer Kennard (1870-1948) : his contribution to malacology, Quaternary research and the Geologists Association.  Proceedings of the Geologists Association 101, 239-258.

A.S.Kennard b. London 5 July 1870, died at 161 Mackenzie Road, Beckenham on 11 June 1948. President of the Geologists Association 1944-1945.

Kennard, A.S.  1895.  Pleistocene Mollusca of Crayford.  Science Gossip ns 2, 39-40.

"There are shells comprising a typical loess fauna from 'Reculver, Kent' in his collection in the BMNH (Natural History Museum) and these have come from the primary loess that blankets the Tertiaries at this site" (Preece 1990)

Loess in Britain X Brick buildings

Wight, J.A.  1972.  Brick Building in England: From the Middle Ages to 1550.  John Baker, 4, 5 & 6 Soho Square, London,  439p.

Smalley, I.J.  1987.  The nature of 'brickearth' and the location of early brick buildings in Britain. British Brick Society Information no.41, 4-11.

Smalley, I.J.  1985/6.  Loess bricks in Britain.  Bulletin of the Experimental Firing Group 4, 55-66 (reprinted in Loess Letter 70, 4-15, 2013; see www.loessletter.msu.edu).

If the loess/brickearth is concentrated in the south-east of England then the brick buildings should also be there. In particular the early brick buildings- built from bricks made from easily accessible local brickearth. Jane Wight has a great map in her book.

An interesting feature of this map is the way that the Weald region is outlined by a lack of buildings. The Weald was a region lacking in loess- there had been loess deposited in the Weald by the same events which spread loess material over the North and South Downs, but the Wealden material was carried away by local rivers.. 

Many of the early brick buildings in London were built from the Thames valley brickearths. The most spectacular brick building in Britain is probably Hampton Court Palace- arguably the most impressive loess deposit in the country

 

Loess in Britain IX Reculver

It has been suggested (O'Hara-Dhand 2015; pers.comm.)  that there could be an interesting loess deposit at Reculver, on the North Kent coast (the coast of Herne Bay and Whitstable).  Reculver is near to Ospringe; the loess is the North Kent loess, sitting on top of the chalk of the North Downs.
There are rumours that palaeosols have been detected in the Reculver loess; it would certainly be useful if some palaeosols can be found. The thickish loess in south Essex does contain palaeosols- and we need more palaeosols in southern England. The loess on the chalk of the North and South Downs is remarkably widespread- more investigation needed here.

Preece, R.C.  1990.  The molluscan fauna of Late Devensian loess from Reculver, Kent.  Journal of Conchology 33, 295

Loess in Britain VIII The Ospringe Project

The Ospringe project was a NERC-funded study of the nature of the soil structure collapse phenomenon in loess ground [the process sometimes known as hydroconsolidation or hydrocollapse]. It started at the Windy Day meeting at Nottingham Trent University on the 2nd April 1997.  The initial structure of the project was sketched out on the same day, on the train from Nottingham to Leicester. It eventually involved several universities (Loughborough, Leicester, Nottingham Trent) and the British Geological Survey at Keyworth.  It eventually ended in 2015 with the publication of the 'mineralogy & fabric' paper.

Milodowski, A.E.,  Northmore, K.J.,  Kemp, S.J.,  Entwisle, D.C.,  Gunn, D.A.,  Jackson, P.D.,  Boardman, D. I.,  Zoumpakis, A.,  Rogers, C.D.F.,  Dixon, N.,  Jefferson, I.,  Smalley, I.J., Clarke, M.   2015.  The mineralogy and fabric of 'Brickearth'  in Kent, UK and their relationship to engineering behaviour.  Bulletin of Engineering Geology and the Environment  74,  1187-1211

In this detailed paper you can find a very satisfactory explanation of the mechanism of hydroconsolidation- which in effect shows how the metastable loess deposit formed by aeolian  deposition takes on the property of collapsibility which allows hydroconsolidation to happen, and may lead to subsidence in some situations. Note the separation of metastability and collapsibility, and the assigning of separate causes. The development of collapsibility might be thought of as an aspect of loessification- this was discussed by Smalley & Markovic(2014)- a spin-off from Milodowski et al (2015) which actually appeared before the key paper was published.

Smalley, I.J., Markovic, S.B.  2014.  Loessification and hydroconsolidation:  there is a connection.  Catena 117,  94-99. 

Zourmpakis, A., Boardman, D.I.,  Rogers, C.D.F., Jefferson, I.,  Gunn, D.A.,  Jackson, P.D.,  Northmore, K.J.,  Entwisle, D.C.,  Nelder, L.M., Dixon, N.  2006.  Case study of a loess collapse field trial in Kent, SE England.  Quarterly Journal of Engineering Geology and Hydrogeology 39, 131-150

"..  a field trial of hydrocollapse in loessic  brickearth deposits.  The site chosen was a working quarry used as a source of brickearth for the local brickworks at Ospringe, just east of the town of Faversham.

 

 

 

 

Loess in Britain VII Crayford

Kennard, A.S.  1944.  The Crayford brickearths.  Proceedings of the Geologists Association 55,  121-167.

Smalley, I.J.  1984.  The Crayford brickearths and other loess materials in the Thames valley. Loess Letter no.12,  34-39  (see www.loessletter.msu.edu)

Bull, A.J.  1942.  Pleistocene chronology.  Proceedings of the Geologists Association  53,  1-45.

"During the early and middle parts of this last glaciation, brickearths were spread over the country to the south of the ice-sheets. These brickearths have received much attention at Crayford, where they overlie the Taplow gravels. At Crayford the lower brickearth is about 20 feet thick and contains Elephas primigenius, Rhinoceros antiquitates, and Ovibos moschaties indicative of a cold steppe climate."

Kirkaldy, J.F., Bull, A.J.  1940.  The geomorphology of the rivers of the southern Weald.  Proceedings of the Geologists Association  115-150.

"A further complication, whose widespread occurrence does not appear to have been previously recognized, is that the whole country is mantled with a sheet of fine-grained unstratified brown loam of a loess-like character, which is commonly one to three feet in thickness and occurs al all levels over the area to the north of the Downs."

The Crayford Brickearths Project (of Durham University); report by Beccy Scott in Quaternary Newsletter no.117 February 2009-  this report is easily accessible because it was reprinted in Loess Letter 62 October 2009 pp.34-38; see www.loessletter.msu.edu for online version. There is still action on the Crayford project and Dr.Scott anticipates more progress.

Digression: Corbicula & MIS5
In the Kennard (1944) paper on the Crayford Brickearths  there is a very useful map showing the disposition of the brickearth and the location of of the old brick pits. There is also a section of the deposits based on earlier work by R.H.Chandler (1914); this shows the brickearth divided into an upper deposit and a lower deposit- separated by a 'Cyrena' bed. The bed is roughly at 40-50 feet (~12m) above OD. On the map Cyrena becomes Corbicula- exposed on both sides of the Bexleyheath Line railway. Corbicula- a famous marine bivalve; Pleistocene Corbicula beds act as litho- and climostratigraphic units of fluvial late Lower and Middle Pleistocene warm stage deposits.

Meijer,T., Preece, R.C.  2000.  A review of the occurrence of Corbicula in the Pleistocene of North-West Europe.  Geologie en Mijnbouw 79, 241-255.

Gaudenyi, T., Nenadic, D., Stejic,P., Jovanovic, M., Bogicevic, K.  2015.  The stratigraphy of the Serbian Pleistocene Corbicula beds.  Quaternary International 357,  4-21.

The waters rose after the deposition of the lower brickearth; the Corbicula flourished and left their traces. The climate was warm and sea-levels were high. It suggests that the Corbicula beds may have been deposited during MIS5- the Last Interglacial, so they date roughly to 100,000 BP; the lower loess is older than this, and the upper is younger. The dates obtained for the British loess tend to be younger (see LiB dating section).

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Loess in Britain VI Pegwell Bay

The Geology of Pegwell Bay.  Peter Golding: Kent Geologists Group; www.kgg.org.uk/pegnotes.pdf.

Pitcher, W.S., Shearman, D.J., Pugh, D.C.  1954.  The loess of Pegwell Bay, Kent, and its associated frost soils. Geological Magazine 91, 308-314.

Weir, A.H., Catt, J.A., Madgett, P.A.  1971.  Postglacial soil formation in the loess of Pegwell Bay, Kent (England).  Geoderma 5, 131-149.

The simple map shows the setting of the Pegwell Bay loess. Pegwell Bay is where the River Stour flows out into the Channel. The river flows through the North Downs from Ashford to Canterbury; the headwaters drain a region in the Weald; the north-eastern part of the Weald, east of the Medway drainage.  In the classic 'rivers and loess' situation the Pegwell Bay loess is the product of the River Stour, and is composed of loess material initially deposited in the Weald of Kent.

Burrin, P.J.  1981.  Loess in the Weald. Proceedings of the Geologists Association 92, 87-92. see also R.W.Gallois PGA 93, 316

Fookes, P.G., Best, R.  1968.  Geotechnical properties and geological aspects of the Pegwell Bay loess, East Kent. PGA 147, 41-44

Fookes, P.G., Best, R.  1969.  Consolidation characteristics of some late Pleistocene periglacial metastable soils of East Kent.  Quarterly Journal of Engineering Geology 2, 103-128.

Pegwell Bay by William Dyce.

Loess in Britain V Dene Holes & Stonehenge

So- what is a dene-hole?  The term is thought to be a corruption of Dane-hole; it was thought that they were dug by ancient Danes in ancient times.  Look in google and you find a cluster of localities: Bexley, Gravesend, Grays, Essex, Dartford, Thurrock, Strood, Swanley... All places on the chalk in the north-west of Kent or in southern Essex. Not deep, a few metres, they go through the covering material and into the chalk. They are thought to have been chalk mines; the chalk was used by ancient farmers for field dressings. The covering is loess; some of the material that fell on the chalk in S.E.England and is still found on the North and South Downs.

The dene holes give a good indication of the depth of the loess, particularly in N.W.Kent. The location of the dene-holes at Dartford and Bexley places them quite near the Crayford brickearths- one of the very substantial deposits of brickearth on the southern bank of the Thames. Crayford provided a lot of bricks in the Victorian times; Kentish bricks were used to build Buckingham Palace. There is no scientific study of loess facts revealed by dene-holes; they are part of an un-appreciated landscape of modest loess which spreads across all of southern Britain.
It has been claimed that there is a loessic relevance to the location and construction of Stonehenge- the greatest, oldest, and most impressive of British monuments. Science tends to look at the petrography and mineralogy of the rocks, or reconstructions of ancient astronomy, or actual archaeological discoveries...    The thin layer of loess which separates the ground surface from the chalk beneath was important. The cohesive nature of loess allows a deep, stable, steep sided pit to be constructed- into which, after considerable effort, a large stone construction unit can be placed. The ability to build the location pit is important; and has not been hitherto appreciated. A Stonehenge pit is a lot like a dene hole- but bigger, and of greater significance.

 

Loess in Britain IV South Coast

Martin, E.A.  1929.  The Pleistocene Cliff-Formation of Brighton.  South Eastern Naturalist and Antiquarian  34,  60-72.

".. there is a considerable deposit of brickearth along the Hove levels, resting, where the two are found together, on the sands which are seen at the East end of Shoreham Harbour. If this brickearth be a loess, it is more than likely that it came about as a deposit from the ice which flowed across the West Sussex plaimns down from the hills."

"One frequently sees discussion going on as to the formation of the loess, but there is nothing very mysterious about its origin. Richthofen has shown..  What is really the problem is the source of the material..  Penck and others have shown that it has a distinct relation to the glaciated parts of Europe."

Palmer, L.S., Cooke, J.H.  1923.  The Pleistocene deposits of the Portsmouth district- and their relation to man.  Proceedings of the Geologists Association  34,  252-282.

Favis-Mortlock, D., Boardman, J., Bell, M.  1997.   Modelling long-term anthropogenic erosion of a loess cover: South Downs UK.  Holocene 7, 79-89.

Reynolds, P.J., Fisher, G.C.  1985.  Loessic soils near Hook, South-East Hampshire. Proceedings of the Hampshire Field Club & Archaeological Society 41,  51-62.

"Many soil profiles in south Hampsghire are wholly or partially developed in the silty superficial sediment known as 'brickearth'. The Hampshire brickearth reaches considerable thickness at Barton-on-Sea and in the Itchen valley around Eastleigh, but generally it is less than 1.5m thick and overlies Pleistocene gravels..

Brickearth is known to be widespread in the Portsmouth district (Palmer & Cooke 1923) and the first modern mapping of soils developed in brickearth was by Kay (1939) in the area around the Hamble river."

Loess in Britain III Chalk Heath Soils

Perrin, R.M.S.  1956.  Nature of Chalk Heath soils.   Nature 178, 31-33

Perrin, R.M.S., Davies, H., Fysh, M.D.  1974.  Distribution of late Pleistocene aeolian deposits in eastern and southern England.  Nature 248,  320-324.

The Perrin (1956) paper in Nature was a significant contribution to the study of loessic materials and deposits in Britain.  He showed that some soils to the west of London were formed by deposition of silty material on top of chalk substrates.

"The object of the work reported in my previous communication was simply to determine whether the soils on some well-developed chalk heaths could have been formed purely by solution of chalk."
                                                                                                                           RMSP  1957