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).
.
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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