Kimmeridge Clay (Redirected from Kimmeridge Clay Formation)
Kimmeridge Clay | |
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Stratigraphic range: | |
Type | Geological formation |
Unit of | Ancholme Group (onshore), Humber Group (offshore) |
Sub-units | Birch Sandstone Member Burns Sandstone Member Claymore Sandstone Member Dirk Sandstone Member Magnus Sandstone Member Ptarmigan Sandstone Member Ribble Sandstone Member |
Underlies | Portland Sand Formation, Speeton Clay Formation, Spilsby Sandstone |
Overlies | Ampthill Clay, Corallian Group |
Lithology | |
Primary | Mudstone |
Other | Siltstone, Sandstone, Conglomerate |
Location | |
Region | England (surface) North Sea (subsurface) |
Country | United Kingdom |
Type section | |
Named for | Kimmeridge Bay |
Location | Type area - coastal outcrops from Black Head, Weymouth to Chapman's Pool |
The Kimmeridge Clay is a sedimentary deposit of fossiliferous marine clay which is of Late Jurassic to lowermost Cretaceous age and occurs in southern and eastern England and in the North Sea. This rock formation is the major source rock for North Sea oil. The fossil fauna of the Kimmeridge Clay includes turtles, crocodiles, sauropods, plesiosaurs, pliosaurs and ichthyosaurs, as well as a number of invertebrate species.
Description
This section needs expansion. You can help by adding to it. (May 2016) |
Kimmeridge Clay is named after the village of Kimmeridge on the Dorset coast of England, where it is well exposed and forms part of the Jurassic Coast World Heritage Site. Onshore, it is of Late Jurassic (Kimmeridgian) age and outcrops across England, in a band stretching from Dorset in the south-west, north-east to North Yorkshire. Offshore, it extends into the Lower Cretaceous (Berriasian Stage) and it is found throughout the Southern, Central and Northern North Sea.
The foundations of the Humber Bridge on the southern (Barton) side of the bridge are on Kimmeridge Clay beneath superficial deposits, under the Humber estuary.
Economic importance
Kimmeridge Clay is of great economic importance, being the major source rock for oil fields in the North Sea hydrocarbon province. It has distinctive physical properties and log responses.
Vertebrate fauna
Color key
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Notes Uncertain or tentative taxa are in small text; |
Fauna uncovered from the Kimmeridge Clay include:
Ray-finned fish
Ray-finned fishes of the Kimmeridge clay Formation | ||||||
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Genus | Species | Location | Stratigraphic Position | Abundance | Notes | Images |
Indeterminate |
Dorset |
Most common Kimmeridge clay fish, known from several complete specimens |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Dorset |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Dorset |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Dorset |
One specimen, a fin |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Dorset |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Dorset |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Dorset |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Dorset |
Housed at the etches collection, discovered by Steve Etches |
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H.tenuirostris |
Dorset |
Rare |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Dorset |
Rare |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Dorset |
Rare, one complete specimen |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Dorset |
Fairly common, multiple near complete specimens. |
Housed at the etches collection, discovered by Steve Etches |
Lobe-finned fish
Lobe-finned fishes of the Kimmeridge clay Formation | ||||||
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Genus | Species | Location | Stratigraphic Position | Abundance | Notes | Images |
Indeterminate |
Dorset |
One specimen, cranial material |
Coelacanth. Housed at the etches collection, discovered by Steve Etches. More than 2 metres long |
Cartilaginous fish
Cartilaginous fishes of the Kimmeridge clay Formation | ||||||
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Genus | Species | Location | Stratigraphic Position | Abundance | Notes | Images |
Indeterminate |
Dorset |
Known from many dorsal spines |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Known from many dorsal spines |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Known from many dorsal spines, perhaps a complete head |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
One specimen |
Housed at the etches collection, discovered by Steve Etches |
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Indeterminate |
Known from a complete specimen, and other isolated remains |
Housed at the etches collection, discovered by Steve Etches |
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Kimmerobatis |
K. etchesi |
Known from multiple partial skeletons |
A spathobatid ray | |||
Durnonovariaodus | D. maiseyi | Pectinatites pectinatus ammonite zone | One partial skeleton | A hybodontid |
Turtles
Turtles of the Kimmeridge clay Formation | ||||||
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Genus | Species | Location | Stratigraphic Position | Abundance | Notes | Images |
Craspedochelys | C. passmorei | Swindon | "NHMUK R5871 (holotype), subcomplete shell with associated postcranial remains, including parts of the girdles, the left humerus, and partial cervical vertebrae" | Thalassochelydian sea turtle | ||
Achelonia | A. formosa | Ely, Cambridgeshire | "CAMSM J29898 to CAMSM J29955 (holotype), a partial, disarticulated skeleton" | Thalassochelydian sea turtle, formerly considered the distinct species "Enaliochelys chelonia" | ||
Pelobatochelys | P. blakii | Weymouth | Carapace fragments | Thalassochelydian sea turtle | ||
Plesiochelys | P. etalloni | "basicranium with partial otic chambers and fragment of the right maxilla" | Thalassochelydian sea turtle | |||
Thalassemys | T. bruntrutana, T. hugii | Isle of Purbeck (bruntrutana), Abingdon, Oxfordshire (hugii) | "A partial carapace and associated limb and girdle elements (NHMUK R8699)" (Purbeck) "A large shell (OUMNH J.66966)" (Oxfordshire) | Thalassochelydian sea turtle | ||
Tropidemys | P. langii | Weymouth | "NHMUK OR44178b, an isolated neural; NHMUK OR45920, right costals 1–3; NHMUK OR45921, a left first costal; NHMUK R2733, a left fourth costal" | Thalassochelydian sea turtle |
Archosaurs
Thalattosuchians
Genus | Species | Location | Member | Abundance | Notes | Images |
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B. megarhinus |
A pelagic teleosaurid. |
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C. gracilis |
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D. maximus |
A geosaurine metriorhynchid | |||||
M. brevirostris |
A metriorhynchine metriorhynchid | |||||
P. manseli |
A geosaurine metriorhynchid | |||||
T. carpenteri |
A geosaurine metriorhynchid | |||||
T. coryphaeus |
A geosaurine metriorhynchid |
Ornithischians
Indeterminate ankylosaur osteoderms have been found in Wiltshire, England. Indeterminate stegosaurid remains have been found in Dorset and Wiltshire, England.
Genus | Species | Location | Member | Abundance | Notes | Images |
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C. prestwichii |
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"Fragmentary skull and skeleton." |
Iguanodontian | |||
D. armatus |
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vertebrae, a massive right femur (thigh bone), ribs and a near complete pelvis. |
Stegosaur. Wiltshire remains include specimens previously referred to Omosaurus armatus and O. hastiger. | |||
Indeterminate |
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Kimmeridge clay remains considered to represent a possible close relative of Bugenasaura are now regarded as the remains of an indeterminate euornithopod.(The specimen may have had its locality and horizon mislabelled.) | ||||
O.armatus |
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Reclassified as Dacentrurus armatus because the generic name Omosaurus was preoccupied. | ||||
O. hastiger |
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Saurischians
Indeterminate ornithomimmid remains have been found in Dorset, England. An undescribed theropod genus was found in Dorset.
Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
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B. suffosus |
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"[Seven] dorsal and sacral centra." |
Considered a nomen dubium. | |||
C. humerocristatus |
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Now Duriatitan. | ||||
Indeterminate |
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Remains previously referred to an indeterminate species of Cetiosaurus are now regarded as indeterminate sauropod material. | ||||
D. humerocristatus |
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G. megalonyx |
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Remains previously referred to Gigantosaurus megalonyx are now regarded as indeterminate sauropod material. | ||||
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"Humerus." |
Remains previously referred to Ischyrosaurus manseli are now regarded as indeterminate sauropod material. | ||||
J. langhami |
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Partial skeleton |
A primitive tyrannosaur | |||
Torvosaurus | Indeterminate | Swindon, Dorset | Tibia (OUMNH J.29886) and maxilla fragment, collected separately | A megalosaurid | ||
Indeterminate |
|
A tooth from Foxhangers, Wiltshire (NHMUK 46388), phalanges from an unspecified locality in Wiltshire (DZSWS 3009), and a proximal caudal verte-
bra from Shotover, Oxfordshire (OUMNH J.47134). |
Remains previously referred to Megalosaurus are now regarded as indeterminate theropod material. | |||
Indeterminate |
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Remains previously attributed to one or more indeterminate species of Ornithopsis (incl. O. leedsii) are now regarded as possible indeterminate sauropod material. |
Pterosaurs
Genus | Species | location | Material | Notes | Images |
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Cuspicephalus | C. scarfi |
Dorset |
Partial Skull | Missing Crest, lower jaw and dentition | |
R.etchesi |
Dorset |
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indeterminate |
Dorset |
Plesiosaurs
Genus | Species | Location | Member | Abundance | Notes | Images |
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B. swindoniensis |
Plesiosaur of unknown affinities |
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C. megadeirus |
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C. trochantericus |
Nomen dubium | |||||
K. langhami |
A cryptoclidid | |||||
"P." manseli |
Distinct from Colymbosaurus. | |||||
P. brachydeirus |
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P. brachyspondylus |
Nomen dubium | |||||
P. carpenteri |
A thalassophonean pliosaurid | |||||
P. kevani |
A thalassophonean pliosaurid | |||||
P. portentificus |
A nomen dubium | |||||
P. ?rossicus |
A thalassophonean pliosaurid; taxonomic identification of specimens tentative | |||||
P. westburyensis |
A thalassophonean pliosaurid | |||||
P. sp. 1 |
Partial skeleton, CAMSM J.35991 |
A thalassophonean pliosaurid; previously assigned to the nomen dubium P. brachyspondylus | ||||
P. sp. 2 |
Mandible, NHMUK PV OR 39362 |
A thalassophonean pliosaurid; previously assigned to the nomen dubium P. macromerus | ||||
Indeterminate |
Ichthyosaurs
Genus | Species | Location | Stratigraphic Position | Abundance | Notes | Images |
---|---|---|---|---|---|---|
B.extremus |
Dorset |
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G.mordax |
Dorset |
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Indeterminate |
Dorset |
Giant, near complete specimen. Proposed to have been 6 metres long when complete. Housed at the Etches collection in dorset. | ||||
M.trigonus |
Dorset |
Nomen dubium - classified by a single vertebra | ||||
N.enthekiodon |
Dorset |
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T. etchesi |
Dorset |
The Pectinatites pectinatus ammonite zone |
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Indeterminate |
Dorset |
Invertebrates
The invertebrate fauna of the Kimmeridge Clay includes:
- Mollusca:
- Cardium striatulum
- Ostrea deltoidea
- Gryphaea (Exogyra) virgula
- Trigonellites
- Belemnotheutis
- Etchesia
- Arthropoda:
- Phlyctosoma sp.
- Eryma sp.
- Magitalatimana sp.
- Mechochirus sp.
- Archaeolepas redtenbacheri
See also
- Geologic formations of England
- Jurassic System of Europe
- Jurassic England
- Kimmeridgian Stage
- Tithonian Stage
- Lower Cretaceous Series of Europe
- Cretaceous England
- Berriasian Stage
- Shale formations
- Shallow marine deposits
- Source rock formations
- Fossiliferous stratigraphic units of Europe
- Paleontology in England
- Geography of Dorset
- Geology of the North Sea
- Energy in Europe