Weald Clay
Weald Clay | |
---|---|
Ma | |
Type | Geological formation |
Unit of | Wealden Group |
Sub-units | Horsham Stone Member |
Underlies | Atherfield Clay Formation |
Overlies | Tunbridge Wells Sand Formation |
Thickness | up to 460 m |
Lithology | |
Primary | Shale, Mudstone |
Other | Siltstone, Sandstone, Limestone, Ironstone |
Location | |
Region | England |
Country | UK |
Type section | |
Named for | Weald |
Extent of the Weald Clay within the Weald Basin, shown with horizontal lines |
Weald Clay or the Weald Clay Formation is a
The formation was deposited in lagoonal, lacustrine and alluvial conditions that varied from freshwater to brackish.[2] The clay alternates with other subordinate lithologies, notably hard red-weathering beds of ironstone, limestone (Sussex Marble) and sandstones, notably including the calcareous sandstone unit referred to as the Horsham Stone. It has a gradual, conformable contact with the underlying Tunbridge Wells Sand Formation, and has a sharp, unconformable contact with the overlying Atherfield Clay Formation, a shallow marine unit deposited after marine transgression during the Aptian.
Physical properties
The weathered and unweathered forms of the Weald Clay have 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
Vertebrates
Vertebrates reported from the Weald Clay | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
B. walkeri |
Smokejack Clay Pit | Upper Weald Clay |
Multiple partial skulls, one of which had an associated postcranial skeleton.[3] |
A spinosaurid | ||
H. rudgwickensis |
Rudgwick Brickworks | Upper Weald Clay |
"Vertebrae, partial fore and hindlimbs, osteoderms."[4] |
A dubious |
||
Iguanodon | I. bernissartensis | Smokejack Clay Pit | Upper Weald Clay | Iguanodontian, also known from the Wessex Formation. | ||
Mantellisaurus | M. atherfieldensis | Smokejack Clay Pit | Upper Weald Clay | Iguanodontian, also known from the Wessex Formation | ||
V. canaliculatus[7] |
Heathfield | Lower Weald Clay |
A dryosaurid, also known from the Wessex Formation |
|||
Leptocleidus | L. superstes[8] | NHM R4828 (holotype) | Pliosauroid | |||
Wyleyia[9] | W. valdensis[9] |
|
||||
Dorsetisaurus | Indeterminate | Keymer Tile Works | ||||
Sauropoda | Indeterminate | Smokejacks, Bexhill | ||||
Anura | Indeterminate | Keymer Tile Works | Lower | Maxillary fragment[10] | ||
Urodela | Indeterminate | Keymer Tile Works | Lower | Atlas vertebra | Has been suggested to have a close relationship with Balveherpeton from Germany.[11] |
Invertebrates
Numerous insect species are known from several localities in the Weald Clay, including Rudgwick Brickworks,[12] Auclaye Brickworks,[13] Smokejacks[14] and Clockhouse Brickworks[15][16][17]
Invertebrates reported from the Weald Clay | ||||||
---|---|---|---|---|---|---|
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
Principiala[18] | P. rudgwickensis | Rudgwick Brickworks | Upper Weald Clay | Single partial fore-wing | An Ithonidae lacewing, the second in Principiala | |
Englathauma | E. crabbi | Rudgwick Brickworks | BMB 021962/3 almost complete forewing | A englathaumatid scorpionfly
|
||
E. mellishae | Smokejacks | Wing and wing fragments | ||||
Cretophasmomima[19] | C. traceyae | Smokejacks | Forewing | A stick insect | ||
Valdicossus | V. mikewebsteri[20] | Smokejacks | Upper | Hindwing | A member of Palaeontinidae | |
V. chesteri[21] | Cooden Beach | Lower | Hindwing | |||
Ilerdocossus | I. prowsei [20] | Clockhouse Brickworks | Lower | A member of Palaeontinidae | ||
Proraphidia | P. hopkinsi[22] | A member of Mesoraphidiidae | ||||
Turanophlebia | T. anglicana[23] | Dragonfly, member of Tarsophlebiidae | ||||
Brochocoleus | B. keenani[24] B. tobini | Smokejacks | Upper | Member of Ommatidae | ||
Diluticupes | D. crowsonae | |||||
Zygadenia | Z. tuberculata,[25] Z. angliae[26] | |||||
Cionocoleus | C. elizabethae, C. watsoni [27] C. minimus | |||||
Omma | O. elongatum | Keymer Tile Works | Lower |
See also
- Wealden District
- London Clay
- Oxford Clay
- List of dinosaur-bearing rock formations
Footnotes
- ^ "Wealden Clay Formation". The BGS Lexicon of Named Rock Units. British Geological Survey. Retrieved 14 December 2014.
- .
- ^ "Table 4.1," in Weishampel, et al. (2004). Page 72.
- ^ "Table 17.1," in Weishampel, et al. (2004). Page 367.
- ^ Raven, T. J., P. M. Barrett, S. B. Pond, and S. C. R. Maidment. 2020. Osteology and taxonomy of British Wealden Supergroup (Berriasian–Aptian) ankylosaurs (Ornithischia, Ankylosauria). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2020.1826956
- ^ 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.
- ^ 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
- ^ "Reassessment of the Lower Cretaceous (Barremian) pliosauroid Leptocleidus superstes Andrews, 1922 and other plesiosaur remains from the nonmarine Wealden succession of southern England | Oxford Academic". academic.oup.com. Retrieved 16 November 2017.
- ^ a b c "10.18 West Sussex, England; 1. Hastings Beds" in Weishampel, et al. (2004). Page 559.
- )
- S2CID 225440583.
- ^ "Rudgwick Brickworks, Upper Weald Clay (Cretaceous of the United Kingdom)". fossilworks.org. Retrieved 17 December 2021.
- ^ "Auclaye Brickworks (BMB collection) (Cretaceous of the United Kingdom)". paleobiodb.org. Retrieved 26 January 2020.
- ^ "Smokejacks Brickworks (Cretaceous of the United Kingdom)". paleobiodb.org. Retrieved 26 January 2020.
- ^ "Clockhouse Brickworks (MNEMG collection) (Cretaceous of the United Kingdom)". fossilworks.org. Retrieved 17 December 2021.
- ^ "Clockhouse Brickworks (BMNH collection) (Cretaceous of the United Kingdom)". fossilworks.org. Retrieved 17 December 2021.
- ^ "Clockhouse Brickworks (BMB collection): Late/Upper Hauterivian, United Kingdom". paleobiodb.org. Retrieved 26 January 2020.
- .
- S2CID 214327966.
- ^ S2CID 134479224.
- ISSN 1175-5334.
- ^ J. E. Jepson and E. A. Jarzembowski. 2008. Two new species of snakefly (Insecta: Raphidioptera) from the Lower Cretaceous of England and Spain with a review of other fossil raphidiopterans from the Jurassic/Cretaceous transition. Alavesia 2:193-201
- ^ G. Fleck, G. Bechly, X. Martínez-Delclòs, E. A. Jarzembowski, and A. Nel. 2004. A revision of the Upper Jurassic-Lower Cretaceous dragonfly family Tarsophlebiidae, with a discussion on the phylogenetic positions of the Tarsophlebiidae and Sieblosiidae (Insecta, Odonatoptera, Panodonata. Geodiversitas 26(1):33-59
- ISSN 0195-6671.
- ISSN 0195-6671.
- ^ A. G. Ponomarenko. 2006. On the Types of Mesozoic Archostematan Beetles (Insecta, Coleoptera, Archostemata) in the Natural History Museum, London. Paleontological Journal 40(1):90-9
- ^ E. A. Jarzembowski, E. V. Yan, B. Wang and H. Zhang. 2013. Ommatin beetles (Insecta: Coleoptera) from the Lower Cretaceous of northeast China and southern England. Terrestrial Arthropod Reviews 6:135-161
References
- Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.