Weald Clay

Weald Clay
Stratigraphic range: Hauterivian-Barremian, 136–125 Ma
Type Geological formation
Unit of Wealden Group
Underlies Atherfield Clay Formation
Overlies Tunbridge Wells Sand Formation
Thickness up to 460 m
Location
Region England
Country  UK

Weald Clay or the Weald Clay Formation is a Lower Cretaceous sedimentary rock underlying areas of South East England. It is part of the Wealden Group of rocks.[1] The clay is named after the Weald, an area of Sussex and Kent. It varies from orange and grey in colour and is used in brickmaking.

The un-weathered form is blue/grey, and the yellow/orange is the weathered form; they have quite different physical properties. Blue looks superficially like a soft slate, is quite dry and hard and will support the weight of buildings quite easily. Because it is quite impermeable, and so dry, it does not get broken by tree roots. It is typically found at 750mm down below a layer of yellow clay. Yellow, found on the surface, absorbs water quite readily so becomes very soft in the winter.

The two different types make quite different bricks.

Paleofauna

Dinosaurs reported from the Weald Clay
Genus Species Location Stratigraphic position Material Notes Images

Baryonyx

B. walkeri

Multiple partial skulls, one of which had an associated postcranial skeleton.[2]

Horshamosaurus

H. rudgwickensis

"Vertebrae, partial fore and hindlimbs, osteoderms."[3]

An ankylosaur belonging to Polacanthinae. Originally named as a species of Polacanthus.[4]

Principiala[5]

P. rudgwickensis

Rudgwick Brickworks

Upper Weald Clay

Single partial fore-wing

An Ithonidae lacewing, the second in Principiala

Valdosaurus

V. canaliculatus[6]

An iguanodontian

See also

Footnotes

  1. "Wealden Clay Formation". The BGS Lexicon of Named Rock Units. British Geological Survey. Retrieved 14 December 2014.
  2. "Table 4.1," in Weishampel, et al. (2004). Page 72.
  3. "Table 17.1," in Weishampel, et al. (2004). Page 367.
  4. Blows, W.T., 2015, British Polacanthid Dinosaurs – Observations on the History and Palaeontology of the UK Polacanthid Armoured Dinosaurs and their Relatives, Siri Scientific Press, 220 pp.
  5. Jepson, JE; Makarkin, VN; Jarzembowski, E (2009). "New lacewings (Insecta: Neuroptera) from the Lower Cretaceous Wealden supergroup of Southern England". Cretaceous Research 30: 1325–1338. doi:10.1016/j.cretres.2009.07.012.
  6. Galton, P.M., 2009, "Notes on Neocomian (Late Cretaceous) ornithopod dinosaurs from England - Hypsilophodon, Valdosaurus, "Camptosaurus", "Iguanodon" - and referred specimens from Romania and elsewhere", Revue de Paléobiologie 28(1): 211-273

References


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